chore(all): memory and thread safe storage

- settings: get filter choices from storage for settings validation
- updater: update servers to the storage
- storage: minimal deep copying and data duplication
- storage: add merged servers mutex for thread safety
- connection: filter servers in storage
- formatter: format servers to Markdown in storage
- PIA: get server by name from storage directly
- Updater: get servers count from storage directly
- Updater: equality check done in storage, fix #882

cmd/gluetun/main.go

@@ -215,9 +215,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		return err
 	}
 
-	allServers := storage.GetServers()
-
-	err = allSettings.Validate(allServers)
+	err = allSettings.Validate(storage)
 	if err != nil {
 		return err
 	}
@@ -378,7 +376,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 
 	vpnLogger := logger.New(log.SetComponent("vpn"))
 	vpnLooper := vpn.NewLoop(allSettings.VPN, allSettings.Firewall.VPNInputPorts,
-		allServers, ovpnConf, netLinker, firewallConf, routingConf, portForwardLooper,
+		storage, ovpnConf, netLinker, firewallConf, routingConf, portForwardLooper,
 		cmder, publicIPLooper, unboundLooper, vpnLogger, httpClient,
 		buildInfo, *allSettings.Version.Enabled)
 	vpnHandler, vpnCtx, vpnDone := goshutdown.NewGoRoutineHandler(
@@ -386,8 +384,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 	go vpnLooper.Run(vpnCtx, vpnDone)
 
 	updaterLooper := updater.NewLooper(allSettings.Updater,
-		allServers, storage, vpnLooper.SetServers, httpClient,
-		logger.New(log.SetComponent("updater")))
+		storage, httpClient, logger.New(log.SetComponent("updater")))
 	updaterHandler, updaterCtx, updaterDone := goshutdown.NewGoRoutineHandler(
 		"updater", goroutine.OptionTimeout(defaultShutdownTimeout))
 	// wait for updaterLooper.Restart() or its ticket launched with RunRestartTicker

internal/cli/formatservers.go

@@ -10,7 +10,6 @@ import (
 
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/storage"
 	"golang.org/x/text/cases"
 	"golang.org/x/text/language"
@@ -80,9 +79,8 @@ func (c *CLI) FormatServers(args []string) error {
 	if err != nil {
 		return fmt.Errorf("cannot create servers storage: %w", err)
 	}
-	currentServers := storage.GetServers()
 
-	formatted := formatServers(currentServers, providerToFormat)
+	formatted := storage.FormatToMarkdown(providerToFormat)
 
 	output = filepath.Clean(output)
 	file, err := os.OpenFile(output, os.O_TRUNC|os.O_WRONLY|os.O_CREATE, 0644)
@@ -103,11 +101,3 @@ func (c *CLI) FormatServers(args []string) error {
 
 	return nil
 }
-
-func formatServers(allServers models.AllServers, provider string) (formatted string) {
-	servers, ok := allServers.ProviderToServers[provider]
-	if !ok {
-		panic(fmt.Sprintf("unknown provider in format map: %s", provider))
-	}
-	return servers.ToMarkdown(provider)
-}

internal/cli/openvpnconfig.go

@@ -25,18 +25,17 @@ func (c *CLI) OpenvpnConfig(logger OpenvpnConfigLogger, source sources.Source) e
 	if err != nil {
 		return err
 	}
-	allServers := storage.GetServers()
 
 	allSettings, err := source.Read()
 	if err != nil {
 		return err
 	}
 
-	if err = allSettings.Validate(allServers); err != nil {
+	if err = allSettings.Validate(storage); err != nil {
 		return err
 	}
 
-	providerConf := provider.New(*allSettings.VPN.Provider.Name, allServers, time.Now)
+	providerConf := provider.New(*allSettings.VPN.Provider.Name, storage, time.Now)
 	connection, err := providerConf.GetConnection(allSettings.VPN.Provider.ServerSelection)
 	if err != nil {
 		return err

internal/cli/update.go

@@ -2,20 +2,17 @@ package cli
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
 	"net"
 	"net/http"
-	"os"
 	"strings"
 	"time"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/storage"
 	"github.com/qdm12/gluetun/internal/updater"
 )
@@ -83,41 +80,19 @@ func (c *CLI) Update(ctx context.Context, args []string, logger UpdaterLogger) e
 	if err != nil {
 		return fmt.Errorf("cannot create servers storage: %w", err)
 	}
-	currentServers := storage.GetServers()
 
-	updater := updater.New(options, httpClient, currentServers, logger)
-	allServers, err := updater.UpdateServers(ctx)
+	updater := updater.New(options, httpClient, storage, logger)
+	err = updater.UpdateServers(ctx)
 	if err != nil {
 		return fmt.Errorf("cannot update server information: %w", err)
 	}
 
-	if endUserMode {
-		if err := storage.FlushToFile(&allServers); err != nil {
-			return fmt.Errorf("cannot write updated information to file: %w", err)
-		}
-	}
-
 	if maintainerMode {
-		if err := writeToEmbeddedJSON(c.repoServersPath, &allServers); err != nil {
-			return fmt.Errorf("cannot write updated information to file: %w", err)
+		err := storage.FlushToFile(c.repoServersPath)
+		if err != nil {
+			return fmt.Errorf("cannot write servers data to embedded JSON file: %w", err)
 		}
 	}
 
 	return nil
 }
-
-func writeToEmbeddedJSON(repoServersPath string,
-	allServers *models.AllServers) error {
-	const perms = 0600
-	f, err := os.OpenFile(repoServersPath,
-		os.O_TRUNC|os.O_WRONLY|os.O_CREATE, perms)
-	if err != nil {
-		return err
-	}
-
-	defer f.Close()
-
-	encoder := json.NewEncoder(f)
-	encoder.SetIndent("", "  ")
-	return encoder.Encode(allServers)
-}

internal/configuration/settings/provider.go

@@ -6,7 +6,6 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/constants/vpn"
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gotree"
 )
 
@@ -23,7 +22,7 @@ type Provider struct {
 }
 
 // TODO v4 remove pointer for receiver (because of Surfshark).
-func (p *Provider) validate(vpnType string, allServers models.AllServers) (err error) {
+func (p *Provider) validate(vpnType string, storage Storage) (err error) {
 	// Validate Name
 	var validNames []string
 	if vpnType == vpn.OpenVPN {
@@ -42,7 +41,7 @@ func (p *Provider) validate(vpnType string, allServers models.AllServers) (err e
 			ErrVPNProviderNameNotValid, *p.Name, helpers.ChoicesOrString(validNames))
 	}
 
-	err = p.ServerSelection.validate(*p.Name, allServers)
+	err = p.ServerSelection.validate(*p.Name, storage)
 	if err != nil {
 		return fmt.Errorf("server selection: %w", err)
 	}

internal/configuration/settings/serverselection.go

@@ -68,21 +68,19 @@ var (
 )
 
 func (ss *ServerSelection) validate(vpnServiceProvider string,
-	allServers models.AllServers) (err error) {
+	storage Storage) (err error) {
 	switch ss.VPN {
 	case vpn.OpenVPN, vpn.Wireguard:
 	default:
 		return fmt.Errorf("%w: %s", ErrVPNTypeNotValid, ss.VPN)
 	}
 
-	countryChoices, regionChoices, cityChoices,
-		ispChoices, nameChoices, hostnameChoices, err := getLocationFilterChoices(vpnServiceProvider, ss, allServers)
+	filterChoices, err := getLocationFilterChoices(vpnServiceProvider, ss, storage)
 	if err != nil {
 		return err // already wrapped error
 	}
 
-	err = validateServerFilters(*ss, countryChoices, regionChoices, cityChoices,
-		ispChoices, nameChoices, hostnameChoices)
+	err = validateServerFilters(*ss, filterChoices)
 	if err != nil {
 		if errors.Is(err, helpers.ErrNoChoice) {
 			return fmt.Errorf("for VPN service provider %s: %w", vpnServiceProvider, err)
@@ -135,63 +133,48 @@ func (ss *ServerSelection) validate(vpnServiceProvider string,
 	return nil
 }
 
-func getLocationFilterChoices(vpnServiceProvider string, ss *ServerSelection,
-	allServers models.AllServers) (
-	countryChoices, regionChoices, cityChoices,
-	ispChoices, nameChoices, hostnameChoices []string,
+func getLocationFilterChoices(vpnServiceProvider string,
+	ss *ServerSelection, storage Storage) (filterChoices models.FilterChoices,
 	err error) {
-	providerServers, ok := allServers.ProviderToServers[vpnServiceProvider]
-	if !ok && vpnServiceProvider != providers.Custom {
-		panic(fmt.Sprintf("VPN service provider unknown: %s", vpnServiceProvider))
-	}
-	servers := providerServers.Servers
-	countryChoices = validation.ExtractCountries(servers)
-	regionChoices = validation.ExtractRegions(servers)
-	cityChoices = validation.ExtractCities(servers)
-	ispChoices = validation.ExtractISPs(servers)
-	nameChoices = validation.ExtractServerNames(servers)
-	hostnameChoices = validation.ExtractHostnames(servers)
+	filterChoices = storage.GetFilterChoices(vpnServiceProvider)
 
 	if vpnServiceProvider == providers.Surfshark {
 		// // Retro compatibility
 		// TODO v4 remove
-		regionChoices = append(regionChoices, validation.SurfsharkRetroLocChoices()...)
-		if err := helpers.AreAllOneOf(ss.Regions, regionChoices); err != nil {
-			return nil, nil, nil, nil, nil, nil, fmt.Errorf("%w: %s", ErrRegionNotValid, err)
+		filterChoices.Regions = append(filterChoices.Regions, validation.SurfsharkRetroLocChoices()...)
+		if err := helpers.AreAllOneOf(ss.Regions, filterChoices.Regions); err != nil {
+			return models.FilterChoices{}, fmt.Errorf("%w: %s", ErrRegionNotValid, err)
 		}
 		*ss = surfsharkRetroRegion(*ss)
 	}
 
-	return countryChoices, regionChoices, cityChoices,
-		ispChoices, nameChoices, hostnameChoices, nil
+	return filterChoices, nil
 }
 
 // validateServerFilters validates filters against the choices given as arguments.
 // Set an argument to nil to pass the check for a particular filter.
-func validateServerFilters(settings ServerSelection,
-	countryChoices, regionChoices, cityChoices, ispChoices,
-	nameChoices, hostnameChoices []string) (err error) {
-	if err := helpers.AreAllOneOf(settings.Countries, countryChoices); err != nil {
+func validateServerFilters(settings ServerSelection, filterChoices models.FilterChoices) (err error) {
+	if err := helpers.AreAllOneOf(settings.Countries, filterChoices.Countries); err != nil {
 		return fmt.Errorf("%w: %s", ErrCountryNotValid, err)
 	}
 
-	if err := helpers.AreAllOneOf(settings.Regions, regionChoices); err != nil {
+	if err := helpers.AreAllOneOf(settings.Regions, filterChoices.Regions); err != nil {
 		return fmt.Errorf("%w: %s", ErrRegionNotValid, err)
 	}
 
-	if err := helpers.AreAllOneOf(settings.Cities, cityChoices); err != nil {
+	if err := helpers.AreAllOneOf(settings.Cities, filterChoices.Cities); err != nil {
 		return fmt.Errorf("%w: %s", ErrCityNotValid, err)
 	}
 
-	if err := helpers.AreAllOneOf(settings.ISPs, ispChoices); err != nil {
+	if err := helpers.AreAllOneOf(settings.ISPs, filterChoices.ISPs); err != nil {
 		return fmt.Errorf("%w: %s", ErrISPNotValid, err)
 	}
 
-	if err := helpers.AreAllOneOf(settings.Hostnames, hostnameChoices); err != nil {
+	if err := helpers.AreAllOneOf(settings.Hostnames, filterChoices.Hostnames); err != nil {
 		return fmt.Errorf("%w: %s", ErrHostnameNotValid, err)
 	}
 
-	if err := helpers.AreAllOneOf(settings.Names, nameChoices); err != nil {
+	if err := helpers.AreAllOneOf(settings.Names, filterChoices.Names); err != nil {
 		return fmt.Errorf("%w: %s", ErrNameNotValid, err)
 	}
 

internal/configuration/settings/settings.go

@@ -24,10 +24,14 @@ type Settings struct {
 	Pprof         pprof.Settings
 }
 
+type Storage interface {
+	GetFilterChoices(provider string) models.FilterChoices
+}
+
 // Validate validates all the settings and returns an error
 // if one of them is not valid.
 // TODO v4 remove pointer for receiver (because of Surfshark).
-func (s *Settings) Validate(allServers models.AllServers) (err error) {
+func (s *Settings) Validate(storage Storage) (err error) {
 	nameToValidation := map[string]func() error{
 		"control server":  s.ControlServer.validate,
 		"dns":             s.DNS.validate,
@@ -42,7 +46,7 @@ func (s *Settings) Validate(allServers models.AllServers) (err error) {
 		"version":         s.Version.validate,
 		// Pprof validation done in pprof constructor
 		"VPN": func() error {
-			return s.VPN.validate(allServers)
+			return s.VPN.validate(storage)
 		},
 	}
 
@@ -91,7 +95,7 @@ func (s *Settings) MergeWith(other Settings) {
 }
 
 func (s *Settings) OverrideWith(other Settings,
-	allServers models.AllServers) (err error) {
+	storage Storage) (err error) {
 	patchedSettings := s.copy()
 	patchedSettings.ControlServer.overrideWith(other.ControlServer)
 	patchedSettings.DNS.overrideWith(other.DNS)
@@ -106,7 +110,7 @@ func (s *Settings) OverrideWith(other Settings,
 	patchedSettings.Version.overrideWith(other.Version)
 	patchedSettings.VPN.overrideWith(other.VPN)
 	patchedSettings.Pprof.MergeWith(other.Pprof)
-	err = patchedSettings.Validate(allServers)
+	err = patchedSettings.Validate(storage)
 	if err != nil {
 		return err
 	}

internal/configuration/settings/updater.go

@@ -35,17 +35,18 @@ func (u Updater) Validate() (err error) {
 			ErrUpdaterPeriodTooSmall, *u.Period, minPeriod)
 	}
 
-	for i, provider := range u.Providers {
+	validProviders := providers.All()
+	for _, provider := range u.Providers {
 		valid := false
-		for _, validProvider := range providers.All() {
+		for _, validProvider := range validProviders {
 			if provider == validProvider {
 				valid = true
 				break
 			}
 		}
 		if !valid {
-			return fmt.Errorf("%w: %s at index %d",
-				ErrVPNProviderNameNotValid, provider, i)
+			return fmt.Errorf("%w: %q can only be one of %s",
+				ErrVPNProviderNameNotValid, provider, helpers.ChoicesOrString(validProviders))
 		}
 	}
 

internal/configuration/settings/vpn.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
 	"github.com/qdm12/gluetun/internal/constants/vpn"
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gotree"
 )
 
@@ -21,7 +20,7 @@ type VPN struct {
 }
 
 // TODO v4 remove pointer for receiver (because of Surfshark).
-func (v *VPN) validate(allServers models.AllServers) (err error) {
+func (v *VPN) validate(storage Storage) (err error) {
 	// Validate Type
 	validVPNTypes := []string{vpn.OpenVPN, vpn.Wireguard}
 	if !helpers.IsOneOf(v.Type, validVPNTypes...) {
@@ -29,7 +28,7 @@ func (v *VPN) validate(allServers models.AllServers) (err error) {
 			ErrVPNTypeNotValid, v.Type, strings.Join(validVPNTypes, ", "))
 	}
 
-	err = v.Provider.validate(v.Type, allServers)
+	err = v.Provider.validate(v.Type, storage)
 	if err != nil {
 		return fmt.Errorf("provider settings: %w", err)
 	}

internal/models/filters.go

@@ -0,0 +1,10 @@
+package models
+
+type FilterChoices struct {
+	Countries []string
+	Regions   []string
+	Cities    []string
+	ISPs      []string
+	Names     []string
+	Hostnames []string
+}

internal/models/getservers.go

@@ -1,51 +0,0 @@
-package models
-
-import (
-	"net"
-)
-
-func (a AllServers) GetCopy() (allServersCopy AllServers) {
-	allServersCopy.Version = a.Version
-	allServersCopy.ProviderToServers = make(map[string]Servers, len(a.ProviderToServers))
-	for provider, servers := range a.ProviderToServers {
-		allServersCopy.ProviderToServers[provider] = Servers{
-			Version:   servers.Version,
-			Timestamp: servers.Timestamp,
-			Servers:   copyServers(servers.Servers),
-		}
-	}
-	return allServersCopy
-}
-
-func copyServers(servers []Server) (serversCopy []Server) {
-	if servers == nil {
-		return nil
-	}
-
-	serversCopy = make([]Server, len(servers))
-	for i, server := range servers {
-		serversCopy[i] = server
-		serversCopy[i].IPs = copyIPs(server.IPs)
-	}
-
-	return serversCopy
-}
-
-func copyIPs(toCopy []net.IP) (copied []net.IP) {
-	if toCopy == nil {
-		return nil
-	}
-
-	copied = make([]net.IP, len(toCopy))
-	for i := range toCopy {
-		copied[i] = copyIP(toCopy[i])
-	}
-
-	return copied
-}
-
-func copyIP(toCopy net.IP) (copied net.IP) {
-	copied = make(net.IP, len(toCopy))
-	copy(copied, toCopy)
-	return copied
-}

internal/models/getservers_test.go

@@ -1,173 +0,0 @@
-package models
-
-import (
-	"net"
-	"testing"
-
-	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-func Test_AllServers_GetCopy(t *testing.T) {
-	allServers := AllServers{
-		Version: 1,
-		ProviderToServers: map[string]Servers{
-			providers.Cyberghost: {
-				Version: 2,
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Expressvpn: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Fastestvpn: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.HideMyAss: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Ipvanish: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Ivpn: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Mullvad: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Nordvpn: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Perfectprivacy: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Privado: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.PrivateInternetAccess: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Privatevpn: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Protonvpn: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Purevpn: {
-				Version: 1,
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Surfshark: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Torguard: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.VPNUnlimited: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Vyprvpn: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Wevpn: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-			providers.Windscribe: {
-				Servers: []Server{{
-					IPs: []net.IP{{1, 2, 3, 4}},
-				}},
-			},
-		},
-	}
-
-	servers := allServers.GetCopy()
-
-	assert.Equal(t, allServers, servers)
-}
-
-func Test_copyIPs(t *testing.T) {
-	t.Parallel()
-
-	testCases := map[string]struct {
-		toCopy []net.IP
-		copied []net.IP
-	}{
-		"nil": {},
-		"empty": {
-			toCopy: []net.IP{},
-			copied: []net.IP{},
-		},
-		"single IP": {
-			toCopy: []net.IP{{1, 1, 1, 1}},
-			copied: []net.IP{{1, 1, 1, 1}},
-		},
-		"two IPs": {
-			toCopy: []net.IP{{1, 1, 1, 1}, {2, 2, 2, 2}},
-			copied: []net.IP{{1, 1, 1, 1}, {2, 2, 2, 2}},
-		},
-	}
-
-	for name, testCase := range testCases {
-		testCase := testCase
-		t.Run(name, func(t *testing.T) {
-			t.Parallel()
-
-			// Reserver leading 9 for copy modifications below
-			for _, ipToCopy := range testCase.toCopy {
-				require.NotEqual(t, 9, ipToCopy[0])
-			}
-
-			copied := copyIPs(testCase.toCopy)
-
-			assert.Equal(t, testCase.copied, copied)
-
-			if len(copied) > 0 {
-				original := testCase.toCopy[0][0]
-				testCase.toCopy[0][0] = 9
-				assert.NotEqual(t, 9, copied[0][0])
-				testCase.toCopy[0][0] = original
-
-				copied[0][0] = 9
-				assert.NotEqual(t, 9, testCase.toCopy[0][0])
-			}
-		})
-	}
-}

internal/models/server.go

@@ -2,6 +2,7 @@ package models
 
 import (
 	"net"
+	"reflect"
 )
 
 type Server struct {
@@ -26,3 +27,28 @@ type Server struct {
 	PortForward bool     `json:"port_forward,omitempty"`
 	IPs         []net.IP `json:"ips,omitempty"`
 }
+
+func (s *Server) Equal(other Server) (equal bool) {
+	if !ipsAreEqual(s.IPs, other.IPs) {
+		return false
+	}
+
+	serverCopy := *s
+	serverCopy.IPs = nil
+	other.IPs = nil
+	return reflect.DeepEqual(serverCopy, other)
+}
+
+func ipsAreEqual(a, b []net.IP) (equal bool) {
+	if len(a) != len(b) {
+		return false
+	}
+
+	for i := range a {
+		if !a[i].Equal(b[i]) {
+			return false
+		}
+	}
+
+	return true
+}

internal/models/server_test.go

@@ -0,0 +1,120 @@
+package models
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Server_Equal(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		a     *Server
+		b     Server
+		equal bool
+	}{
+		"same IPs": {
+			a: &Server{
+				IPs: []net.IP{net.IPv4(1, 2, 3, 4)},
+			},
+			b: Server{
+				IPs: []net.IP{net.IPv4(1, 2, 3, 4)},
+			},
+			equal: true,
+		},
+		"same IP strings": {
+			a: &Server{
+				IPs: []net.IP{net.IPv4(1, 2, 3, 4)},
+			},
+			b: Server{
+				IPs: []net.IP{{1, 2, 3, 4}},
+			},
+			equal: true,
+		},
+		"different IPs": {
+			a: &Server{
+				IPs: []net.IP{{1, 2, 3, 4}, {2, 3, 4, 5}},
+			},
+			b: Server{
+				IPs: []net.IP{{1, 2, 3, 4}, {1, 2, 3, 4}},
+			},
+		},
+		"all fields equal": {
+			a: &Server{
+				VPN:         "vpn",
+				Country:     "country",
+				Region:      "region",
+				City:        "city",
+				ISP:         "isp",
+				Owned:       true,
+				Number:      1,
+				ServerName:  "server_name",
+				Hostname:    "hostname",
+				TCP:         true,
+				UDP:         true,
+				OvpnX509:    "x509",
+				RetroLoc:    "retroloc",
+				MultiHop:    true,
+				WgPubKey:    "wgpubkey",
+				Free:        true,
+				Stream:      true,
+				PortForward: true,
+				IPs:         []net.IP{net.IPv4(1, 2, 3, 4)},
+			},
+			b: Server{
+				VPN:         "vpn",
+				Country:     "country",
+				Region:      "region",
+				City:        "city",
+				ISP:         "isp",
+				Owned:       true,
+				Number:      1,
+				ServerName:  "server_name",
+				Hostname:    "hostname",
+				TCP:         true,
+				UDP:         true,
+				OvpnX509:    "x509",
+				RetroLoc:    "retroloc",
+				MultiHop:    true,
+				WgPubKey:    "wgpubkey",
+				Free:        true,
+				Stream:      true,
+				PortForward: true,
+				IPs:         []net.IP{net.IPv4(1, 2, 3, 4)},
+			},
+			equal: true,
+		},
+		"different field": {
+			a: &Server{
+				VPN: "vpn",
+			},
+			b: Server{
+				VPN: "other vpn",
+			},
+		},
+	}
+
+	for name, testCase := range testCases {
+		testCase := testCase
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			ipsOfANotNil := testCase.a.IPs != nil
+			ipsOfBNotNil := testCase.b.IPs != nil
+
+			equal := testCase.a.Equal(testCase.b)
+
+			assert.Equal(t, testCase.equal, equal)
+
+			// Ensure IPs field is not modified
+			if ipsOfANotNil {
+				assert.NotNil(t, testCase.a)
+			}
+			if ipsOfBNotNil {
+				assert.NotNil(t, testCase.b)
+			}
+		})
+	}
+}

internal/models/servers.go

@@ -15,18 +15,6 @@ type AllServers struct {
 	ProviderToServers map[string]Servers
 }
 
-func (a *AllServers) ServersSlice(provider string) []Server {
-	if provider == providers.Custom {
-		return nil
-	}
-
-	servers, ok := a.ProviderToServers[provider]
-	if !ok {
-		panic(fmt.Sprintf("provider %s not found in all servers", provider))
-	}
-	return copyServers(servers.Servers)
-}
-
 var _ json.Marshaler = (*AllServers)(nil)
 
 // MarshalJSON marshals all servers to JSON.

internal/provider/common/mocks.go

@@ -0,0 +1,66 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/qdm12/gluetun/internal/provider/common (interfaces: Storage)
+
+// Package common is a generated GoMock package.
+package common
+
+import (
+	reflect "reflect"
+
+	gomock "github.com/golang/mock/gomock"
+	settings "github.com/qdm12/gluetun/internal/configuration/settings"
+	models "github.com/qdm12/gluetun/internal/models"
+)
+
+// MockStorage is a mock of Storage interface.
+type MockStorage struct {
+	ctrl     *gomock.Controller
+	recorder *MockStorageMockRecorder
+}
+
+// MockStorageMockRecorder is the mock recorder for MockStorage.
+type MockStorageMockRecorder struct {
+	mock *MockStorage
+}
+
+// NewMockStorage creates a new mock instance.
+func NewMockStorage(ctrl *gomock.Controller) *MockStorage {
+	mock := &MockStorage{ctrl: ctrl}
+	mock.recorder = &MockStorageMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use.
+func (m *MockStorage) EXPECT() *MockStorageMockRecorder {
+	return m.recorder
+}
+
+// FilterServers mocks base method.
+func (m *MockStorage) FilterServers(arg0 string, arg1 settings.ServerSelection) ([]models.Server, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "FilterServers", arg0, arg1)
+	ret0, _ := ret[0].([]models.Server)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// FilterServers indicates an expected call of FilterServers.
+func (mr *MockStorageMockRecorder) FilterServers(arg0, arg1 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "FilterServers", reflect.TypeOf((*MockStorage)(nil).FilterServers), arg0, arg1)
+}
+
+// GetServerByName mocks base method.
+func (m *MockStorage) GetServerByName(arg0, arg1 string) (models.Server, bool) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "GetServerByName", arg0, arg1)
+	ret0, _ := ret[0].(models.Server)
+	ret1, _ := ret[1].(bool)
+	return ret0, ret1
+}
+
+// GetServerByName indicates an expected call of GetServerByName.
+func (mr *MockStorageMockRecorder) GetServerByName(arg0, arg1 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetServerByName", reflect.TypeOf((*MockStorage)(nil).GetServerByName), arg0, arg1)
+}

internal/provider/common/mocks_generate_test.go

@@ -0,0 +1,5 @@
+package common
+
+// Exceptionally, the storage mock is exported since it is used by all
+// provider subpackages tests, and it reduces test code duplication a lot.
+//go:generate mockgen -destination=mocks.go -package $GOPACKAGE . Storage

internal/provider/common/storage.go

@@ -0,0 +1,12 @@
+package common
+
+import (
+	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+type Storage interface {
+	FilterServers(provider string, selection settings.ServerSelection) (
+		servers []models.Server, err error)
+	GetServerByName(provider, name string) (server models.Server, ok bool)
+}

internal/provider/cyberghost/connection.go

@@ -2,6 +2,7 @@ package cyberghost
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(443, 443, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Cyberghost,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/cyberghost/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Cyberghost),
 	}

internal/provider/expressvpn/connection.go

@@ -2,6 +2,7 @@ package expressvpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(0, 1195, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Expressvpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/expressvpn/connection_test.go

@@ -1,41 +1,63 @@
 package expressvpn
 
 import (
+	"errors"
 	"math/rand"
 	"net"
 	"testing"
 
+	"github.com/golang/mock/gomock"
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
-	"github.com/qdm12/gluetun/internal/provider/utils"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_Provider_GetConnection(t *testing.T) {
 	t.Parallel()
 
+	const provider = providers.Expressvpn
+
+	errTest := errors.New("test error")
+	boolPtr := func(b bool) *bool { return &b }
+
 	testCases := map[string]struct {
-		servers    []models.Server
+		filteredServers []models.Server
+		storageErr      error
 		selection       settings.ServerSelection
 		connection      models.Connection
 		errWrapped      error
 		errMessage      string
+		panicMessage    string
 	}{
-		"no server": {
-			selection:  settings.ServerSelection{}.WithDefaults(providers.Expressvpn),
-			errWrapped: utils.ErrNoServer,
-			errMessage: "no server",
+		"error": {
+			storageErr: errTest,
+			errWrapped: errTest,
+			errMessage: "cannot filter servers: test error",
 		},
-		"no filter": {
-			servers: []models.Server{
-				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
+		"default OpenVPN TCP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
 			},
-			selection: settings.ServerSelection{}.WithDefaults(providers.Expressvpn),
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(true),
+				},
+			}.WithDefaults(provider),
+			panicMessage: "no default OpenVPN TCP port is defined!",
+		},
+		"default OpenVPN UDP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(false),
+				},
+			}.WithDefaults(provider),
 			connection: models.Connection{
 				Type:     vpn.OpenVPN,
 				IP:       net.IPv4(1, 1, 1, 1),
@@ -43,38 +65,14 @@ func Test_Provider_GetConnection(t *testing.T) {
 				Protocol: constants.UDP,
 			},
 		},
-		"target IP": {
+		"default Wireguard port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
 			selection: settings.ServerSelection{
-				TargetIP: net.IPv4(2, 2, 2, 2),
-			}.WithDefaults(providers.Expressvpn),
-			servers: []models.Server{
-				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
-			},
-			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1195,
-				Protocol: constants.UDP,
-			},
-		},
-		"with filter": {
-			selection: settings.ServerSelection{
-				Hostnames: []string{"b"},
-			}.WithDefaults(providers.Expressvpn),
-			servers: []models.Server{
-				{Hostname: "a", IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{Hostname: "b", IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{Hostname: "a", IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
-			},
-			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1195,
-				Protocol: constants.UDP,
-				Hostname: "b",
-			},
+				VPN: vpn.Wireguard,
+			}.WithDefaults(provider),
+			panicMessage: "no default Wireguard port is defined!",
 		},
 	}
 
@@ -82,12 +80,23 @@ func Test_Provider_GetConnection(t *testing.T) {
 		testCase := testCase
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			ctrl := gomock.NewController(t)
 
+			storage := common.NewMockStorage(ctrl)
+			storage.EXPECT().FilterServers(provider, testCase.selection).
+				Return(testCase.filteredServers, testCase.storageErr)
 			randSource := rand.NewSource(0)
 
-			m := New(testCase.servers, randSource)
+			provider := New(storage, randSource)
 
-			connection, err := m.GetConnection(testCase.selection)
+			if testCase.panicMessage != "" {
+				assert.PanicsWithValue(t, testCase.panicMessage, func() {
+					_, _ = provider.GetConnection(testCase.selection)
+				})
+				return
+			}
+
+			connection, err := provider.GetConnection(testCase.selection)
 
 			assert.ErrorIs(t, err, testCase.errWrapped)
 			if testCase.errWrapped != nil {

internal/provider/expressvpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Expressvpn),
 	}

internal/provider/fastestvpn/connection.go

@@ -2,6 +2,7 @@ package fastestvpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(4443, 4443, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Fastestvpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/fastestvpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Fastestvpn),
 	}

internal/provider/hidemyass/connection.go

@@ -2,6 +2,7 @@ package hidemyass
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(8080, 553, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.HideMyAss,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/hidemyass/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.HideMyAss),
 	}

internal/provider/ipvanish/connection.go

@@ -2,6 +2,7 @@ package ipvanish
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(0, 443, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Ipvanish,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/ipvanish/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Ipvanish),
 	}

internal/provider/ivpn/connection.go

@@ -2,6 +2,7 @@ package ivpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(443, 1194, 58237) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Ivpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/ivpn/connection_test.go

@@ -1,41 +1,67 @@
 package ivpn
 
 import (
+	"errors"
 	"math/rand"
 	"net"
 	"testing"
 
+	"github.com/golang/mock/gomock"
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
-	"github.com/qdm12/gluetun/internal/provider/utils"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_Provider_GetConnection(t *testing.T) {
 	t.Parallel()
 
+	const provider = providers.Ivpn
+
+	errTest := errors.New("test error")
+	boolPtr := func(b bool) *bool { return &b }
+
 	testCases := map[string]struct {
-		servers    []models.Server
+		filteredServers []models.Server
+		storageErr      error
 		selection       settings.ServerSelection
 		connection      models.Connection
 		errWrapped      error
 		errMessage      string
 	}{
-		"no server available": {
-			selection:  settings.ServerSelection{}.WithDefaults(providers.Ivpn),
-			errWrapped: utils.ErrNoServer,
-			errMessage: "no server",
+		"error": {
+			storageErr: errTest,
+			errWrapped: errTest,
+			errMessage: "cannot filter servers: test error",
 		},
-		"no filter": {
-			servers: []models.Server{
-				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
+		"default OpenVPN TCP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
 			},
-			selection: settings.ServerSelection{}.WithDefaults(providers.Ivpn),
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(true),
+				},
+			}.WithDefaults(provider),
+			connection: models.Connection{
+				Type:     vpn.OpenVPN,
+				IP:       net.IPv4(1, 1, 1, 1),
+				Port:     443,
+				Protocol: constants.TCP,
+			},
+		},
+		"default OpenVPN UDP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(false),
+				},
+			}.WithDefaults(provider),
 			connection: models.Connection{
 				Type:     vpn.OpenVPN,
 				IP:       net.IPv4(1, 1, 1, 1),
@@ -43,51 +69,36 @@ func Test_Provider_GetConnection(t *testing.T) {
 				Protocol: constants.UDP,
 			},
 		},
-		"target IP": {
+		"default Wireguard port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
 			selection: settings.ServerSelection{
-				TargetIP: net.IPv4(2, 2, 2, 2),
-			}.WithDefaults(providers.Ivpn),
-			servers: []models.Server{
-				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
-			},
+				VPN: vpn.Wireguard,
+			}.WithDefaults(provider),
 			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1194,
+				Type:     vpn.Wireguard,
+				IP:       net.IPv4(1, 1, 1, 1),
+				Port:     58237,
 				Protocol: constants.UDP,
 			},
 		},
-		"with filter": {
-			selection: settings.ServerSelection{
-				Hostnames: []string{"b"},
-			}.WithDefaults(providers.Ivpn),
-			servers: []models.Server{
-				{Hostname: "a", IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{Hostname: "b", IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{Hostname: "a", IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
-			},
-			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1194,
-				Protocol: constants.UDP,
-				Hostname: "b",
-			},
-		},
 	}
 
 	for name, testCase := range testCases {
 		testCase := testCase
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			ctrl := gomock.NewController(t)
 
+			storage := common.NewMockStorage(ctrl)
+			storage.EXPECT().FilterServers(provider, testCase.selection).
+				Return(testCase.filteredServers, testCase.storageErr)
 			randSource := rand.NewSource(0)
 
-			m := New(testCase.servers, randSource)
+			provider := New(storage, randSource)
 
-			connection, err := m.GetConnection(testCase.selection)
+			connection, err := provider.GetConnection(testCase.selection)
 
 			assert.ErrorIs(t, err, testCase.errWrapped)
 			if testCase.errWrapped != nil {

internal/provider/ivpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Ivpn),
 	}

internal/provider/mullvad/connection.go

@@ -2,6 +2,7 @@ package mullvad
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(443, 1194, 51820) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Mullvad,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/mullvad/connection_test.go

@@ -1,41 +1,67 @@
 package mullvad
 
 import (
+	"errors"
 	"math/rand"
 	"net"
 	"testing"
 
+	"github.com/golang/mock/gomock"
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
-	"github.com/qdm12/gluetun/internal/provider/utils"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_Provider_GetConnection(t *testing.T) {
 	t.Parallel()
 
+	const provider = providers.Mullvad
+
+	errTest := errors.New("test error")
+	boolPtr := func(b bool) *bool { return &b }
+
 	testCases := map[string]struct {
-		servers    []models.Server
+		filteredServers []models.Server
+		storageErr      error
 		selection       settings.ServerSelection
 		connection      models.Connection
 		errWrapped      error
 		errMessage      string
 	}{
-		"no server available": {
-			selection:  settings.ServerSelection{}.WithDefaults(providers.Mullvad),
-			errWrapped: utils.ErrNoServer,
-			errMessage: "no server",
+		"error": {
+			storageErr: errTest,
+			errWrapped: errTest,
+			errMessage: "cannot filter servers: test error",
 		},
-		"no filter": {
-			servers: []models.Server{
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(2, 2, 2, 2)}},
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(3, 3, 3, 3)}},
+		"default OpenVPN TCP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
 			},
-			selection: settings.ServerSelection{}.WithDefaults(providers.Mullvad),
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(true),
+				},
+			}.WithDefaults(provider),
+			connection: models.Connection{
+				Type:     vpn.OpenVPN,
+				IP:       net.IPv4(1, 1, 1, 1),
+				Port:     443,
+				Protocol: constants.TCP,
+			},
+		},
+		"default OpenVPN UDP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(false),
+				},
+			}.WithDefaults(provider),
 			connection: models.Connection{
 				Type:     vpn.OpenVPN,
 				IP:       net.IPv4(1, 1, 1, 1),
@@ -43,36 +69,17 @@ func Test_Provider_GetConnection(t *testing.T) {
 				Protocol: constants.UDP,
 			},
 		},
-		"target IP": {
+		"default Wireguard port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
 			selection: settings.ServerSelection{
-				TargetIP: net.IPv4(2, 2, 2, 2),
-			}.WithDefaults(providers.Mullvad),
-			servers: []models.Server{
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(2, 2, 2, 2)}},
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(3, 3, 3, 3)}},
-			},
+				VPN: vpn.Wireguard,
+			}.WithDefaults(provider),
 			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1194,
-				Protocol: constants.UDP,
-			},
-		},
-		"with filter": {
-			selection: settings.ServerSelection{
-				Hostnames: []string{"b"},
-			}.WithDefaults(providers.Mullvad),
-			servers: []models.Server{
-				{VPN: vpn.OpenVPN, UDP: true, Hostname: "a", IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
-				{VPN: vpn.OpenVPN, UDP: true, Hostname: "b", IPs: []net.IP{net.IPv4(2, 2, 2, 2)}},
-				{VPN: vpn.OpenVPN, UDP: true, Hostname: "a", IPs: []net.IP{net.IPv4(3, 3, 3, 3)}},
-			},
-			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1194,
-				Hostname: "b",
+				Type:     vpn.Wireguard,
+				IP:       net.IPv4(1, 1, 1, 1),
+				Port:     51820,
 				Protocol: constants.UDP,
 			},
 		},
@@ -82,12 +89,16 @@ func Test_Provider_GetConnection(t *testing.T) {
 		testCase := testCase
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			ctrl := gomock.NewController(t)
 
+			storage := common.NewMockStorage(ctrl)
+			storage.EXPECT().FilterServers(provider, testCase.selection).
+				Return(testCase.filteredServers, testCase.storageErr)
 			randSource := rand.NewSource(0)
 
-			m := New(testCase.servers, randSource)
+			provider := New(storage, randSource)
 
-			connection, err := m.GetConnection(testCase.selection)
+			connection, err := provider.GetConnection(testCase.selection)
 
 			assert.ErrorIs(t, err, testCase.errWrapped)
 			if testCase.errWrapped != nil {

internal/provider/mullvad/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Mullvad),
 	}

internal/provider/nordvpn/connection.go

@@ -2,6 +2,7 @@ package nordvpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(443, 1194, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Nordvpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/nordvpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Nordvpn),
 	}

internal/provider/perfectprivacy/connection.go

@@ -2,6 +2,7 @@ package perfectprivacy
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(443, 443, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Perfectprivacy,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/perfectprivacy/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Perfectprivacy),
 	}

internal/provider/privado/connection.go

@@ -2,6 +2,7 @@ package privado
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(0, 1194, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Privado,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/privado/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Privado),
 	}

internal/provider/privateinternetaccess/connection.go

@@ -2,6 +2,7 @@ package privateinternetaccess
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/privateinternetaccess/presets"
 	"github.com/qdm12/gluetun/internal/provider/utils"
@@ -20,5 +21,6 @@ func (p *Provider) GetConnection(selection settings.ServerSelection) (
 		defaults.OpenVPNUDPPort = 1197
 	}
 
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.PrivateInternetAccess,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/privateinternetaccess/portforward.go

@@ -15,12 +15,13 @@ import (
 	"strings"
 	"time"
 
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 	"github.com/qdm12/golibs/format"
 )
 
 var (
+	ErrServerNameNotFound = errors.New("server name not found in servers")
 	ErrGatewayIPIsNil     = errors.New("gateway IP address is nil")
 	ErrServerNameEmpty    = errors.New("server name is empty")
 )
@@ -29,11 +30,9 @@ var (
 func (p *Provider) PortForward(ctx context.Context, client *http.Client,
 	logger utils.Logger, gateway net.IP, serverName string) (
 	port uint16, err error) {
-	var server models.Server
-	for _, server = range p.servers {
-		if server.ServerName == serverName {
-			break
-		}
+	server, ok := p.storage.GetServerByName(providers.PrivateInternetAccess, serverName)
+	if !ok {
+		return 0, fmt.Errorf("%w: %s", ErrServerNameNotFound, serverName)
 	}
 
 	if !server.PortForward {

internal/provider/privateinternetaccess/provider.go

@@ -5,11 +5,11 @@ import (
 	"time"
 
 	"github.com/qdm12/gluetun/internal/constants/openvpn"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	timeNow    func() time.Time
 	// Port forwarding
@@ -17,11 +17,11 @@ type Provider struct {
 	authFilePath    string
 }
 
-func New(servers []models.Server, randSource rand.Source,
+func New(storage common.Storage, randSource rand.Source,
 	timeNow func() time.Time) *Provider {
 	const jsonPortForwardPath = "/gluetun/piaportforward.json"
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		timeNow:         timeNow,
 		randSource:      randSource,
 		portForwardPath: jsonPortForwardPath,

internal/provider/privatevpn/connection.go

@@ -2,6 +2,7 @@ package privatevpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(443, 1194, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Privatevpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/privatevpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Privatevpn),
 	}

internal/provider/protonvpn/connection.go

@@ -2,6 +2,7 @@ package protonvpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(443, 1194, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Protonvpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/protonvpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Protonvpn),
 	}

internal/provider/provider.go

@@ -50,52 +50,57 @@ type PortForwarder interface {
 		port uint16, gateway net.IP, serverName string) (err error)
 }
 
-func New(provider string, allServers models.AllServers, timeNow func() time.Time) Provider {
-	serversSlice := allServers.ServersSlice(provider)
+type Storage interface {
+	FilterServers(provider string, selection settings.ServerSelection) (
+		servers []models.Server, err error)
+	GetServerByName(provider, name string) (server models.Server, ok bool)
+}
+
+func New(provider string, storage Storage, timeNow func() time.Time) Provider {
 	randSource := rand.NewSource(timeNow().UnixNano())
 	switch provider {
 	case providers.Custom:
 		return custom.New()
 	case providers.Cyberghost:
-		return cyberghost.New(serversSlice, randSource)
+		return cyberghost.New(storage, randSource)
 	case providers.Expressvpn:
-		return expressvpn.New(serversSlice, randSource)
+		return expressvpn.New(storage, randSource)
 	case providers.Fastestvpn:
-		return fastestvpn.New(serversSlice, randSource)
+		return fastestvpn.New(storage, randSource)
 	case providers.HideMyAss:
-		return hidemyass.New(serversSlice, randSource)
+		return hidemyass.New(storage, randSource)
 	case providers.Ipvanish:
-		return ipvanish.New(serversSlice, randSource)
+		return ipvanish.New(storage, randSource)
 	case providers.Ivpn:
-		return ivpn.New(serversSlice, randSource)
+		return ivpn.New(storage, randSource)
 	case providers.Mullvad:
-		return mullvad.New(serversSlice, randSource)
+		return mullvad.New(storage, randSource)
 	case providers.Nordvpn:
-		return nordvpn.New(serversSlice, randSource)
+		return nordvpn.New(storage, randSource)
 	case providers.Perfectprivacy:
-		return perfectprivacy.New(serversSlice, randSource)
+		return perfectprivacy.New(storage, randSource)
 	case providers.Privado:
-		return privado.New(serversSlice, randSource)
+		return privado.New(storage, randSource)
 	case providers.PrivateInternetAccess:
-		return privateinternetaccess.New(serversSlice, randSource, timeNow)
+		return privateinternetaccess.New(storage, randSource, timeNow)
 	case providers.Privatevpn:
-		return privatevpn.New(serversSlice, randSource)
+		return privatevpn.New(storage, randSource)
 	case providers.Protonvpn:
-		return protonvpn.New(serversSlice, randSource)
+		return protonvpn.New(storage, randSource)
 	case providers.Purevpn:
-		return purevpn.New(serversSlice, randSource)
+		return purevpn.New(storage, randSource)
 	case providers.Surfshark:
-		return surfshark.New(serversSlice, randSource)
+		return surfshark.New(storage, randSource)
 	case providers.Torguard:
-		return torguard.New(serversSlice, randSource)
+		return torguard.New(storage, randSource)
 	case providers.VPNUnlimited:
-		return vpnunlimited.New(serversSlice, randSource)
+		return vpnunlimited.New(storage, randSource)
 	case providers.Vyprvpn:
-		return vyprvpn.New(serversSlice, randSource)
+		return vyprvpn.New(storage, randSource)
 	case providers.Wevpn:
-		return wevpn.New(serversSlice, randSource)
+		return wevpn.New(storage, randSource)
 	case providers.Windscribe:
-		return windscribe.New(serversSlice, randSource)
+		return windscribe.New(storage, randSource)
 	default:
 		panic("provider " + provider + " is unknown") // should never occur
 	}

internal/provider/purevpn/connection.go

@@ -2,6 +2,7 @@ package purevpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(80, 53, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Purevpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/purevpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Purevpn),
 	}

internal/provider/surfshark/connection.go

@@ -2,6 +2,7 @@ package surfshark
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(1443, 1194, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Surfshark,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/surfshark/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Surfshark),
 	}

internal/provider/torguard/connection.go

@@ -2,6 +2,7 @@ package torguard
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(1912, 1912, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Torguard,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/torguard/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Torguard),
 	}

internal/provider/utils/connection.go

@@ -1,7 +1,7 @@
 package utils
 
 import (
-	"errors"
+	"fmt"
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
@@ -24,20 +24,20 @@ func NewConnectionDefaults(openvpnTCPPort, openvpnUDPPort,
 	}
 }
 
-var ErrNoServer = errors.New("no server")
+type Storage interface {
+	FilterServers(provider string, selection settings.ServerSelection) (
+		servers []models.Server, err error)
+}
 
-func GetConnection(servers []models.Server,
+func GetConnection(provider string,
+	storage Storage,
 	selection settings.ServerSelection,
 	defaults ConnectionDefaults,
 	randSource rand.Source) (
 	connection models.Connection, err error) {
-	if len(servers) == 0 {
-		return connection, ErrNoServer
-	}
-
-	servers = filterServers(servers, selection)
-	if len(servers) == 0 {
-		return connection, noServerFoundError(selection)
+	servers, err := storage.FilterServers(provider, selection)
+	if err != nil {
+		return connection, fmt.Errorf("cannot filter servers: %w", err)
 	}
 
 	protocol := getProtocol(selection)

internal/provider/utils/connection_test.go

@@ -1,23 +1,30 @@
 package utils
 
 import (
+	"errors"
 	"math/rand"
 	"net"
 	"testing"
 
+	"github.com/golang/mock/gomock"
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_GetConnection(t *testing.T) {
 	t.Parallel()
 
+	errTest := errors.New("test error")
+
 	testCases := map[string]struct {
-		servers         []models.Server
+		provider        string
+		filteredServers []models.Server
+		filterError     error
 		serverSelection settings.ServerSelection
 		defaults        ConnectionDefaults
 		randSource      rand.Source
@@ -25,25 +32,13 @@ func Test_GetConnection(t *testing.T) {
 		errWrapped      error
 		errMessage      string
 	}{
-		"no server": {
-			serverSelection: settings.ServerSelection{}.
-				WithDefaults(providers.Mullvad),
-			errWrapped: ErrNoServer,
-			errMessage: "no server",
-		},
-		"all servers filtered": {
-			servers: []models.Server{
-				{VPN: vpn.Wireguard},
-				{VPN: vpn.Wireguard},
-			},
-			serverSelection: settings.ServerSelection{
-				VPN: vpn.OpenVPN,
-			}.WithDefaults(providers.Mullvad),
-			errWrapped: ErrNoServerFound,
-			errMessage: "no server found: for VPN openvpn; protocol udp",
+		"storage filter error": {
+			filterError: errTest,
+			errWrapped:  errTest,
+			errMessage:  "cannot filter servers: test error",
 		},
 		"server without IPs": {
-			servers: []models.Server{
+			filteredServers: []models.Server{
 				{VPN: vpn.OpenVPN, UDP: true},
 				{VPN: vpn.OpenVPN, UDP: true},
 			},
@@ -58,7 +53,7 @@ func Test_GetConnection(t *testing.T) {
 			errMessage: "no connection to pick from",
 		},
 		"OpenVPN server with hostname": {
-			servers: []models.Server{
+			filteredServers: []models.Server{
 				{
 					VPN:      vpn.OpenVPN,
 					UDP:      true,
@@ -79,7 +74,7 @@ func Test_GetConnection(t *testing.T) {
 			},
 		},
 		"OpenVPN server with x509": {
-			servers: []models.Server{
+			filteredServers: []models.Server{
 				{
 					VPN:      vpn.OpenVPN,
 					UDP:      true,
@@ -101,7 +96,7 @@ func Test_GetConnection(t *testing.T) {
 			},
 		},
 		"server with IPv4 and IPv6": {
-			servers: []models.Server{
+			filteredServers: []models.Server{
 				{
 					VPN: vpn.OpenVPN,
 					UDP: true,
@@ -128,7 +123,7 @@ func Test_GetConnection(t *testing.T) {
 			},
 		},
 		"mixed servers": {
-			servers: []models.Server{
+			filteredServers: []models.Server{
 				{
 					VPN:      vpn.OpenVPN,
 					UDP:      true,
@@ -169,8 +164,14 @@ func Test_GetConnection(t *testing.T) {
 		testCase := testCase
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			ctrl := gomock.NewController(t)
 
-			connection, err := GetConnection(testCase.servers,
+			storage := common.NewMockStorage(ctrl)
+			storage.EXPECT().
+				FilterServers(testCase.provider, testCase.serverSelection).
+				Return(testCase.filteredServers, testCase.filterError)
+
+			connection, err := GetConnection(testCase.provider, storage,
 				testCase.serverSelection, testCase.defaults,
 				testCase.randSource)
 

internal/provider/vpnunlimited/connection.go

@@ -2,6 +2,7 @@ package vpnunlimited
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(0, 1194, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.VPNUnlimited,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/vpnunlimited/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.VPNUnlimited),
 	}

internal/provider/vyprvpn/connection.go

@@ -2,6 +2,7 @@ package vyprvpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(0, 443, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Vyprvpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/vyprvpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Vyprvpn),
 	}

internal/provider/wevpn/connection.go

@@ -2,6 +2,7 @@ package wevpn
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(1195, 1194, 0) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Wevpn,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/wevpn/connection_test.go

@@ -1,43 +1,68 @@
 package wevpn
 
 import (
+	"errors"
 	"math/rand"
 	"net"
 	"testing"
 
+	"github.com/golang/mock/gomock"
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
-	"github.com/qdm12/gluetun/internal/provider/utils"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_Provider_GetConnection(t *testing.T) {
 	t.Parallel()
 
+	const provider = providers.Wevpn
+
+	errTest := errors.New("test error")
+	boolPtr := func(b bool) *bool { return &b }
+
 	testCases := map[string]struct {
-		servers    []models.Server
+		filteredServers []models.Server
+		storageErr      error
 		selection       settings.ServerSelection
 		connection      models.Connection
 		errWrapped      error
 		errMessage      string
+		panicMessage    string
 	}{
-		"no server available": {
+		"error": {
+			storageErr: errTest,
+			errWrapped: errTest,
+			errMessage: "cannot filter servers: test error",
+		},
+		"default OpenVPN TCP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
 			selection: settings.ServerSelection{
-				VPN: vpn.OpenVPN,
-			}.WithDefaults(providers.Wevpn),
-			errWrapped: utils.ErrNoServer,
-			errMessage: "no server",
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(true),
 				},
-		"no filter": {
-			servers: []models.Server{
-				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
+			}.WithDefaults(provider),
+			connection: models.Connection{
+				Type:     vpn.OpenVPN,
+				IP:       net.IPv4(1, 1, 1, 1),
+				Port:     1195,
+				Protocol: constants.TCP,
 			},
-			selection: settings.ServerSelection{}.WithDefaults(providers.Wevpn),
+		},
+		"default OpenVPN UDP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(false),
+				},
+			}.WithDefaults(provider),
 			connection: models.Connection{
 				Type:     vpn.OpenVPN,
 				IP:       net.IPv4(1, 1, 1, 1),
@@ -45,38 +70,14 @@ func Test_Provider_GetConnection(t *testing.T) {
 				Protocol: constants.UDP,
 			},
 		},
-		"target IP": {
+		"default Wireguard port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
 			selection: settings.ServerSelection{
-				TargetIP: net.IPv4(2, 2, 2, 2),
-			}.WithDefaults(providers.Wevpn),
-			servers: []models.Server{
-				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
-			},
-			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1194,
-				Protocol: constants.UDP,
-			},
-		},
-		"with filter": {
-			selection: settings.ServerSelection{
-				Hostnames: []string{"b"},
-			}.WithDefaults(providers.Wevpn),
-			servers: []models.Server{
-				{Hostname: "a", IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{Hostname: "b", IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{Hostname: "a", IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
-			},
-			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1194,
-				Hostname: "b",
-				Protocol: constants.UDP,
-			},
+				VPN: vpn.Wireguard,
+			}.WithDefaults(provider),
+			panicMessage: "no default Wireguard port is defined!",
 		},
 	}
 
@@ -84,12 +85,23 @@ func Test_Provider_GetConnection(t *testing.T) {
 		testCase := testCase
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			ctrl := gomock.NewController(t)
 
+			storage := common.NewMockStorage(ctrl)
+			storage.EXPECT().FilterServers(provider, testCase.selection).
+				Return(testCase.filteredServers, testCase.storageErr)
 			randSource := rand.NewSource(0)
 
-			m := New(testCase.servers, randSource)
+			provider := New(storage, randSource)
 
-			connection, err := m.GetConnection(testCase.selection)
+			if testCase.panicMessage != "" {
+				assert.PanicsWithValue(t, testCase.panicMessage, func() {
+					_, _ = provider.GetConnection(testCase.selection)
+				})
+				return
+			}
+
+			connection, err := provider.GetConnection(testCase.selection)
 
 			assert.ErrorIs(t, err, testCase.errWrapped)
 			if testCase.errWrapped != nil {

internal/provider/wevpn/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Wevpn),
 	}

internal/provider/windscribe/connection.go

@@ -2,6 +2,7 @@ package windscribe
 
 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
@@ -9,5 +10,6 @@ import (
 func (p *Provider) GetConnection(selection settings.ServerSelection) (
 	connection models.Connection, err error) {
 	defaults := utils.NewConnectionDefaults(443, 1194, 1194) //nolint:gomnd
-	return utils.GetConnection(p.servers, selection, defaults, p.randSource)
+	return utils.GetConnection(providers.Windscribe,
+		p.storage, selection, defaults, p.randSource)
 }

internal/provider/windscribe/connection_test.go

@@ -1,41 +1,68 @@
 package windscribe
 
 import (
+	"errors"
 	"math/rand"
 	"net"
 	"testing"
 
+	"github.com/golang/mock/gomock"
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
-	"github.com/qdm12/gluetun/internal/provider/utils"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_Provider_GetConnection(t *testing.T) {
 	t.Parallel()
 
+	const provider = providers.Windscribe
+
+	errTest := errors.New("test error")
+	boolPtr := func(b bool) *bool { return &b }
+
 	testCases := map[string]struct {
-		servers    []models.Server
+		filteredServers []models.Server
+		storageErr      error
 		selection       settings.ServerSelection
 		connection      models.Connection
 		errWrapped      error
 		errMessage      string
+		panicMessage    string
 	}{
-		"no server available": {
-			selection:  settings.ServerSelection{}.WithDefaults(providers.Windscribe),
-			errWrapped: utils.ErrNoServer,
-			errMessage: "no server",
+		"error": {
+			storageErr: errTest,
+			errWrapped: errTest,
+			errMessage: "cannot filter servers: test error",
 		},
-		"no filter": {
-			servers: []models.Server{
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(2, 2, 2, 2)}},
-				{VPN: vpn.OpenVPN, UDP: true, IPs: []net.IP{net.IPv4(3, 3, 3, 3)}},
+		"default OpenVPN TCP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
 			},
-			selection: settings.ServerSelection{}.WithDefaults(providers.Windscribe),
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(true),
+				},
+			}.WithDefaults(provider),
+			connection: models.Connection{
+				Type:     vpn.OpenVPN,
+				IP:       net.IPv4(1, 1, 1, 1),
+				Port:     443,
+				Protocol: constants.TCP,
+			},
+		},
+		"default OpenVPN UDP port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
+			selection: settings.ServerSelection{
+				OpenVPN: settings.OpenVPNSelection{
+					TCP: boolPtr(false),
+				},
+			}.WithDefaults(provider),
 			connection: models.Connection{
 				Type:     vpn.OpenVPN,
 				IP:       net.IPv4(1, 1, 1, 1),
@@ -43,49 +70,41 @@ func Test_Provider_GetConnection(t *testing.T) {
 				Protocol: constants.UDP,
 			},
 		},
-		"target IP": {
+		"default Wireguard port": {
+			filteredServers: []models.Server{
+				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}},
+			},
 			selection: settings.ServerSelection{
-				TargetIP: net.IPv4(2, 2, 2, 2),
-			}.WithDefaults(providers.Windscribe),
-			servers: []models.Server{
-				{IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
-			},
+				VPN: vpn.Wireguard,
+			}.WithDefaults(provider),
 			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
+				Type:     vpn.Wireguard,
+				IP:       net.IPv4(1, 1, 1, 1),
 				Port:     1194,
 				Protocol: constants.UDP,
 			},
 		},
-		"with filter": {
-			selection: settings.ServerSelection{
-				Hostnames: []string{"b"},
-			}.WithDefaults(providers.Windscribe),
-			servers: []models.Server{
-				{Hostname: "a", IPs: []net.IP{net.IPv4(1, 1, 1, 1)}, VPN: vpn.OpenVPN, UDP: true},
-				{Hostname: "b", IPs: []net.IP{net.IPv4(2, 2, 2, 2)}, VPN: vpn.OpenVPN, UDP: true},
-				{Hostname: "a", IPs: []net.IP{net.IPv4(3, 3, 3, 3)}, VPN: vpn.OpenVPN, UDP: true},
-			},
-			connection: models.Connection{
-				Type:     vpn.OpenVPN,
-				IP:       net.IPv4(2, 2, 2, 2),
-				Port:     1194,
-				Hostname: "b",
-				Protocol: constants.UDP,
-			},
-		},
 	}
 
 	for name, testCase := range testCases {
 		testCase := testCase
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			ctrl := gomock.NewController(t)
 
+			storage := common.NewMockStorage(ctrl)
+			storage.EXPECT().FilterServers(provider, testCase.selection).
+				Return(testCase.filteredServers, testCase.storageErr)
 			randSource := rand.NewSource(0)
 
-			provider := New(testCase.servers, randSource)
+			provider := New(storage, randSource)
+
+			if testCase.panicMessage != "" {
+				assert.PanicsWithValue(t, testCase.panicMessage, func() {
+					_, _ = provider.GetConnection(testCase.selection)
+				})
+				return
+			}
 
 			connection, err := provider.GetConnection(testCase.selection)
 
@@ -93,6 +112,7 @@ func Test_Provider_GetConnection(t *testing.T) {
 			if testCase.errWrapped != nil {
 				assert.EqualError(t, err, testCase.errMessage)
 			}
+
 			assert.Equal(t, testCase.connection, connection)
 		})
 	}

internal/provider/windscribe/provider.go

@@ -4,19 +4,19 @@ import (
 	"math/rand"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
 type Provider struct {
-	servers    []models.Server
+	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
 }
 
-func New(servers []models.Server, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source) *Provider {
 	return &Provider{
-		servers:         servers,
+		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Windscribe),
 	}

internal/storage/choices.go

@@ -0,0 +1,27 @@
+package storage
+
+import (
+	"github.com/qdm12/gluetun/internal/configuration/settings/validation"
+	"github.com/qdm12/gluetun/internal/constants/providers"
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+func (s *Storage) GetFilterChoices(provider string) models.FilterChoices {
+	if provider == providers.Custom {
+		return models.FilterChoices{}
+	}
+
+	s.mergedMutex.RLock()
+	defer s.mergedMutex.RUnlock()
+
+	serversObject := s.getMergedServersObject(provider)
+	servers := serversObject.Servers
+	return models.FilterChoices{
+		Countries: validation.ExtractCountries(servers),
+		Regions:   validation.ExtractRegions(servers),
+		Cities:    validation.ExtractCities(servers),
+		ISPs:      validation.ExtractISPs(servers),
+		Names:     validation.ExtractServerNames(servers),
+		Hostnames: validation.ExtractHostnames(servers),
+	}
+}

internal/storage/copy.go

@@ -0,0 +1,32 @@
+package storage
+
+import (
+	"net"
+
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+func copyServer(server models.Server) (serverCopy models.Server) {
+	serverCopy = server
+	serverCopy.IPs = copyIPs(server.IPs)
+	return serverCopy
+}
+
+func copyIPs(toCopy []net.IP) (copied []net.IP) {
+	if toCopy == nil {
+		return nil
+	}
+
+	copied = make([]net.IP, len(toCopy))
+	for i := range toCopy {
+		copied[i] = copyIP(toCopy[i])
+	}
+
+	return copied
+}
+
+func copyIP(toCopy net.IP) (copied net.IP) {
+	copied = make(net.IP, len(toCopy))
+	copy(copied, toCopy)
+	return copied
+}

internal/storage/copy_test.go

@@ -0,0 +1,75 @@
+package storage
+
+import (
+	"net"
+	"testing"
+
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_copyServer(t *testing.T) {
+	t.Parallel()
+
+	server := models.Server{
+		Country: "a",
+		IPs:     []net.IP{{1, 2, 3, 4}},
+	}
+
+	serverCopy := copyServer(server)
+
+	assert.Equal(t, server, serverCopy)
+	// Check for mutation
+	serverCopy.IPs[0][0] = 9
+	assert.NotEqual(t, server, serverCopy)
+}
+
+func Test_copyIPs(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		toCopy []net.IP
+		copied []net.IP
+	}{
+		"nil": {},
+		"empty": {
+			toCopy: []net.IP{},
+			copied: []net.IP{},
+		},
+		"single IP": {
+			toCopy: []net.IP{{1, 1, 1, 1}},
+			copied: []net.IP{{1, 1, 1, 1}},
+		},
+		"two IPs": {
+			toCopy: []net.IP{{1, 1, 1, 1}, {2, 2, 2, 2}},
+			copied: []net.IP{{1, 1, 1, 1}, {2, 2, 2, 2}},
+		},
+	}
+
+	for name, testCase := range testCases {
+		testCase := testCase
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			// Reserver leading 9 for copy modifications below
+			for _, ipToCopy := range testCase.toCopy {
+				require.NotEqual(t, 9, ipToCopy[0])
+			}
+
+			copied := copyIPs(testCase.toCopy)
+
+			assert.Equal(t, testCase.copied, copied)
+
+			if len(copied) > 0 {
+				original := testCase.toCopy[0][0]
+				testCase.toCopy[0][0] = 9
+				assert.NotEqual(t, 9, copied[0][0])
+				testCase.toCopy[0][0] = original
+
+				copied[0][0] = 9
+				assert.NotEqual(t, 9, testCase.toCopy[0][0])
+			}
+		})
+	}
+}

internal/storage/filter.go

@@ -0,0 +1,143 @@
+package storage
+
+import (
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/constants/providers"
+	"github.com/qdm12/gluetun/internal/constants/vpn"
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+// FilterServers filter servers for the given provider and according
+// to the given selection. The filtered servers are deep copied so they
+// are safe for mutation by the caller.
+func (s *Storage) FilterServers(provider string, selection settings.ServerSelection) (
+	servers []models.Server, err error) {
+	if provider == providers.Custom {
+		return nil, nil
+	}
+
+	s.mergedMutex.RLock()
+	defer s.mergedMutex.RUnlock()
+
+	serversObject := s.getMergedServersObject(provider)
+	allServers := serversObject.Servers
+
+	if len(allServers) == 0 {
+		return nil, ErrNoServerFound
+	}
+
+	for _, server := range allServers {
+		if filterServer(server, selection) {
+			continue
+		}
+
+		server = copyServer(server)
+		servers = append(servers, server)
+	}
+
+	if len(servers) == 0 {
+		return nil, noServerFoundError(selection)
+	}
+
+	return servers, nil
+}
+
+func filterServer(server models.Server,
+	selection settings.ServerSelection) (filtered bool) {
+	// Note each condition is split to make sure
+	// we have full testing coverage.
+	if server.VPN != selection.VPN {
+		return true
+	}
+
+	if filterByProtocol(selection, server.TCP, server.UDP) {
+		return true
+	}
+
+	if *selection.MultiHopOnly && !server.MultiHop {
+		return true
+	}
+
+	if *selection.FreeOnly && !server.Free {
+		return true
+	}
+
+	if *selection.StreamOnly && !server.Stream {
+		return true
+	}
+
+	if *selection.OwnedOnly && !server.Owned {
+		return true
+	}
+
+	if filterByPossibilities(server.Country, selection.Countries) {
+		return true
+	}
+
+	if filterByPossibilities(server.Region, selection.Regions) {
+		return true
+	}
+
+	if filterByPossibilities(server.City, selection.Cities) {
+		return true
+	}
+
+	if filterByPossibilities(server.ISP, selection.ISPs) {
+		return true
+	}
+
+	if filterByPossibilitiesUint16(server.Number, selection.Numbers) {
+		return true
+	}
+
+	if filterByPossibilities(server.ServerName, selection.Names) {
+		return true
+	}
+
+	if filterByPossibilities(server.Hostname, selection.Hostnames) {
+		return true
+	}
+
+	// TODO filter port forward server for PIA
+
+	return false
+}
+
+func filterByPossibilities(value string, possibilities []string) (filtered bool) {
+	if len(possibilities) == 0 {
+		return false
+	}
+	for _, possibility := range possibilities {
+		if strings.EqualFold(value, possibility) {
+			return false
+		}
+	}
+	return true
+}
+
+// TODO merge with filterByPossibilities with generics in Go 1.18.
+func filterByPossibilitiesUint16(value uint16, possibilities []uint16) (filtered bool) {
+	if len(possibilities) == 0 {
+		return false
+	}
+	for _, possibility := range possibilities {
+		if value == possibility {
+			return false
+		}
+	}
+	return true
+}
+
+func filterByProtocol(selection settings.ServerSelection,
+	serverTCP, serverUDP bool) (filtered bool) {
+	switch selection.VPN {
+	case vpn.Wireguard:
+		return !serverUDP
+	default: // OpenVPN
+		wantTCP := *selection.OpenVPN.TCP
+		wantUDP := !wantTCP
+		return (wantTCP && !serverTCP) || (wantUDP && !serverUDP)
+	}
+}

internal/storage/flush.go

@@ -4,21 +4,20 @@ import (
 	"encoding/json"
 	"os"
 	"path/filepath"
-
-	"github.com/qdm12/gluetun/internal/models"
 )
 
-var _ Flusher = (*Storage)(nil)
+// FlushToFile flushes the merged servers data to the file
+// specified by path, as indented JSON.
+func (s *Storage) FlushToFile(path string) error {
+	s.mergedMutex.RLock()
+	defer s.mergedMutex.RUnlock()
 
-type Flusher interface {
-	FlushToFile(allServers *models.AllServers) error
+	return s.flushToFile(path)
 }
 
-func (s *Storage) FlushToFile(allServers *models.AllServers) error {
-	return flushToFile(s.filepath, allServers)
-}
-
-func flushToFile(path string, servers *models.AllServers) error {
+// flushToFile flushes the merged servers data to the file
+// specified by path, as indented JSON. It is not thread-safe.
+func (s *Storage) flushToFile(path string) error {
 	dirPath := filepath.Dir(path)
 	if err := os.MkdirAll(dirPath, 0644); err != nil {
 		return err
@@ -28,11 +27,15 @@ func flushToFile(path string, servers *models.AllServers) error {
 	if err != nil {
 		return err
 	}
+
 	encoder := json.NewEncoder(file)
 	encoder.SetIndent("", "  ")
-	if err := encoder.Encode(servers); err != nil {
+
+	err = encoder.Encode(&s.mergedServers)
+	if err != nil {
 		_ = file.Close()
 		return err
 	}
+
 	return file.Close()
 }

internal/storage/formatting.go

@@ -1,4 +1,4 @@
-package utils
+package storage
 
 import (
 	"errors"

internal/storage/servers.go

@@ -1,7 +1,118 @@
 package storage
 
-import "github.com/qdm12/gluetun/internal/models"
+import (
+	"fmt"
+	"time"
 
-func (s *Storage) GetServers() models.AllServers {
-	return s.mergedServers.GetCopy()
+	"github.com/qdm12/gluetun/internal/constants/providers"
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+// SetServers sets the given servers for the given provider
+// in the storage in-memory map and saves all the servers
+// to file.
+// Note the servers given are not copied so the caller must
+// NOT MUTATE them after calling this method.
+func (s *Storage) SetServers(provider string, servers []models.Server) (err error) {
+	if provider == providers.Custom {
+		return
+	}
+
+	s.mergedMutex.Lock()
+	defer s.mergedMutex.Unlock()
+
+	serversObject := s.getMergedServersObject(provider)
+	serversObject.Timestamp = time.Now().Unix()
+	serversObject.Servers = servers
+	s.mergedServers.ProviderToServers[provider] = serversObject
+
+	err = s.flushToFile(s.filepath)
+	if err != nil {
+		return fmt.Errorf("cannot save servers to file: %w", err)
+	}
+	return nil
+}
+
+// GetServerByName returns the server for the given provider
+// and server name. It returns `ok` as false if the server is
+// not found. The returned server is also deep copied so it is
+// safe for mutation and/or thread safe use.
+func (s *Storage) GetServerByName(provider, name string) (
+	server models.Server, ok bool) {
+	if provider == providers.Custom {
+		return server, false
+	}
+
+	s.mergedMutex.RLock()
+	defer s.mergedMutex.RUnlock()
+
+	serversObject := s.getMergedServersObject(provider)
+	for _, server := range serversObject.Servers {
+		if server.ServerName == name {
+			return copyServer(server), true
+		}
+	}
+
+	return server, false
+}
+
+// GetServersCount returns the number of servers for the provider given.
+func (s *Storage) GetServersCount(provider string) (count int) {
+	if provider == providers.Custom {
+		return 0
+	}
+
+	s.mergedMutex.RLock()
+	defer s.mergedMutex.RUnlock()
+
+	serversObject := s.getMergedServersObject(provider)
+	return len(serversObject.Servers)
+}
+
+// FormatToMarkdown Markdown formats the servers for the provider given
+// and returns the resulting string.
+func (s *Storage) FormatToMarkdown(provider string) (formatted string) {
+	if provider == providers.Custom {
+		return ""
+	}
+
+	s.mergedMutex.RLock()
+	defer s.mergedMutex.RUnlock()
+
+	serversObject := s.getMergedServersObject(provider)
+	formatted = serversObject.ToMarkdown(provider)
+	return formatted
+}
+
+// GetServersCount returns the number of servers for the provider given.
+func (s *Storage) ServersAreEqual(provider string, servers []models.Server) (equal bool) {
+	if provider == providers.Custom {
+		return true
+	}
+
+	s.mergedMutex.RLock()
+	defer s.mergedMutex.RUnlock()
+
+	serversObject := s.getMergedServersObject(provider)
+	existingServers := serversObject.Servers
+
+	if len(existingServers) != len(servers) {
+		return false
+	}
+
+	for i := range existingServers {
+		if !existingServers[i].Equal(servers[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (s *Storage) getMergedServersObject(provider string) (serversObject models.Servers) {
+	serversObject, ok := s.mergedServers.ProviderToServers[provider]
+	if !ok {
+		panic(fmt.Sprintf("provider %s not found in in-memory servers map", provider))
+	}
+	return serversObject
 }

internal/storage/storage.go

@@ -2,11 +2,14 @@
 package storage
 
 import (
+	"sync"
+
 	"github.com/qdm12/gluetun/internal/models"
 )
 
 type Storage struct {
 	mergedServers models.AllServers
+	mergedMutex   sync.RWMutex
 	// this is stored in memory to avoid re-parsing
 	// the embedded JSON file on every call to the
 	// SyncServers method.

internal/storage/sync.go

@@ -29,6 +29,9 @@ func (s *Storage) syncServers() (err error) {
 	hardcodedCount := countServers(s.hardcodedServers)
 	countOnFile := countServers(serversOnFile)
 
+	s.mergedMutex.Lock()
+	defer s.mergedMutex.Unlock()
+
 	if countOnFile == 0 {
 		s.logger.Info(fmt.Sprintf(
 			"creating %s with %d hardcoded servers",
@@ -47,7 +50,8 @@ func (s *Storage) syncServers() (err error) {
 		return nil
 	}
 
-	if err := flushToFile(s.filepath, &s.mergedServers); err != nil {
+	err = s.flushToFile(s.filepath)
+	if err != nil {
 		return fmt.Errorf("cannot write servers to file: %w", err)
 	}
 	return nil

internal/updater/loop/loop.go

@@ -9,7 +9,6 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/models"
-	"github.com/qdm12/gluetun/internal/storage"
 	"github.com/qdm12/gluetun/internal/updater"
 )
 
@@ -24,15 +23,13 @@ type Looper interface {
 }
 
 type Updater interface {
-	UpdateServers(ctx context.Context) (allServers models.AllServers, err error)
+	UpdateServers(ctx context.Context) (err error)
 }
 
 type looper struct {
 	state state
 	// Objects
 	updater Updater
-	flusher       storage.Flusher
-	setAllServers func(allServers models.AllServers)
 	logger  Logger
 	// Internal channels and locks
 	loopLock     sync.Mutex
@@ -49,23 +46,26 @@ type looper struct {
 
 const defaultBackoffTime = 5 * time.Second
 
+type Storage interface {
+	SetServers(provider string, servers []models.Server) (err error)
+	GetServersCount(provider string) (count int)
+	ServersAreEqual(provider string, servers []models.Server) (equal bool)
+}
+
 type Logger interface {
 	Info(s string)
 	Warn(s string)
 	Error(s string)
 }
 
-func NewLooper(settings settings.Updater, currentServers models.AllServers,
-	flusher storage.Flusher, setAllServers func(allServers models.AllServers),
+func NewLooper(settings settings.Updater, storage Storage,
 	client *http.Client, logger Logger) Looper {
 	return &looper{
 		state: state{
 			status:   constants.Stopped,
 			settings: settings,
 		},
-		updater:       updater.New(settings, client, currentServers, logger),
-		flusher:       flusher,
-		setAllServers: setAllServers,
+		updater:      updater.New(settings, client, storage, logger),
 		logger:       logger,
 		start:        make(chan struct{}),
 		running:      make(chan models.LoopStatus),
@@ -106,20 +106,19 @@ func (l *looper) Run(ctx context.Context, done chan<- struct{}) {
 	for ctx.Err() == nil {
 		updateCtx, updateCancel := context.WithCancel(ctx)
 
-		serversCh := make(chan models.AllServers)
 		errorCh := make(chan error)
 		runWg := &sync.WaitGroup{}
 		runWg.Add(1)
 		go func() {
 			defer runWg.Done()
-			servers, err := l.updater.UpdateServers(updateCtx)
+			err := l.updater.UpdateServers(updateCtx)
 			if err != nil {
 				if updateCtx.Err() == nil {
 					errorCh <- err
 				}
 				return
 			}
-			serversCh <- servers
+			l.state.setStatusWithLock(constants.Completed)
 		}()
 
 		if !crashed {
@@ -148,16 +147,7 @@ func (l *looper) Run(ctx context.Context, done chan<- struct{}) {
 				updateCancel()
 				runWg.Wait()
 				l.stopped <- struct{}{}
-			case servers := <-serversCh:
-				l.setAllServers(servers)
-				if err := l.flusher.FlushToFile(&servers); err != nil {
-					l.logger.Error(err.Error())
-				}
-				runWg.Wait()
-				l.state.setStatusWithLock(constants.Completed)
-				l.logger.Info("Updated servers information")
 			case err := <-errorCh:
-				close(serversCh)
 				runWg.Wait()
 				l.state.setStatusWithLock(constants.Crashed)
 				l.logAndWait(ctx, err)

internal/updater/providers.go

@@ -3,8 +3,6 @@ package updater
 import (
 	"context"
 	"fmt"
-	"reflect"
-	"time"
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/models"
@@ -31,18 +29,25 @@ import (
 )
 
 func (u *Updater) updateProvider(ctx context.Context, provider string) (err error) {
-	existingServers := u.getProviderServers(provider)
-	minServers := getMinServers(existingServers)
+	existingServersCount := u.storage.GetServersCount(provider)
+	minServers := getMinServers(existingServersCount)
 	servers, err := u.getServers(ctx, provider, minServers)
 	if err != nil {
-		return err
+		return fmt.Errorf("cannot get servers: %w", err)
 	}
 
-	if reflect.DeepEqual(existingServers, servers) {
+	if u.storage.ServersAreEqual(provider, servers) {
 		return nil
 	}
 
-	u.patchProvider(provider, servers)
+	// Note the servers variable must NOT BE MUTATED after this call,
+	// since the implementation does not deep copy the servers.
+	// TODO set in storage in provider updater directly, server by server,
+	// to avoid accumulating server data in memory.
+	err = u.storage.SetServers(provider, servers)
+	if err != nil {
+		return fmt.Errorf("cannot set servers to storage: %w", err)
+	}
 	return nil
 }
 
@@ -101,25 +106,7 @@ func (u *Updater) getServers(ctx context.Context, provider string,
 	return providerUpdater.GetServers(ctx, minServers)
 }
 
-func (u *Updater) getProviderServers(provider string) (servers []models.Server) {
-	providerServers, ok := u.servers.ProviderToServers[provider]
-	if !ok {
-		panic(fmt.Sprintf("provider %s is unknown", provider))
-	}
-	return providerServers.Servers
-}
-
-func getMinServers(servers []models.Server) (minServers int) {
+func getMinServers(existingServersCount int) (minServers int) {
 	const minRatio = 0.8
-	return int(minRatio * float64(len(servers)))
-}
-
-func (u *Updater) patchProvider(provider string, servers []models.Server) {
-	providerServers, ok := u.servers.ProviderToServers[provider]
-	if !ok {
-		panic(fmt.Sprintf("provider %s is unknown", provider))
-	}
-	providerServers.Timestamp = time.Now().Unix()
-	providerServers.Servers = servers
-	u.servers.ProviderToServers[provider] = providerServers
+	return int(minRatio * float64(existingServersCount))
 }

internal/updater/updater.go

@@ -19,7 +19,7 @@ type Updater struct {
 	options settings.Updater
 
 	// state
-	servers models.AllServers
+	storage Storage
 
 	// Functions for tests
 	logger    Logger
@@ -29,6 +29,12 @@ type Updater struct {
 	unzipper  unzip.Unzipper
 }
 
+type Storage interface {
+	SetServers(provider string, servers []models.Server) (err error)
+	GetServersCount(provider string) (count int)
+	ServersAreEqual(provider string, servers []models.Server) (equal bool)
+}
+
 type Logger interface {
 	Info(s string)
 	Warn(s string)
@@ -36,20 +42,20 @@ type Logger interface {
 }
 
 func New(settings settings.Updater, httpClient *http.Client,
-	currentServers models.AllServers, logger Logger) *Updater {
+	storage Storage, logger Logger) *Updater {
 	unzipper := unzip.New(httpClient)
 	return &Updater{
+		options:   settings,
+		storage:   storage,
 		logger:    logger,
 		timeNow:   time.Now,
 		presolver: resolver.NewParallelResolver(settings.DNSAddress.String()),
 		client:    httpClient,
 		unzipper:  unzipper,
-		options:   settings,
-		servers:   currentServers,
 	}
 }
 
-func (u *Updater) UpdateServers(ctx context.Context) (allServers models.AllServers, err error) {
+func (u *Updater) UpdateServers(ctx context.Context) (err error) {
 	caser := cases.Title(language.English)
 	for _, provider := range u.options.Providers {
 		u.logger.Info("updating " + caser.String(provider) + " servers...")
@@ -62,17 +68,17 @@ func (u *Updater) UpdateServers(ctx context.Context) (allServers models.AllServe
 
 		// return the only error for the single provider.
 		if len(u.options.Providers) == 1 {
-			return allServers, err
+			return err
 		}
 
 		// stop updating the next providers if context is canceled.
 		if ctxErr := ctx.Err(); ctxErr != nil {
-			return allServers, ctxErr
+			return ctxErr
 		}
 
 		// Log the error and continue updating the next provider.
 		u.logger.Error(err.Error())
 	}
 
-	return u.servers, nil
+	return nil
 }

internal/vpn/loop.go

@@ -27,12 +27,12 @@ type Looper interface {
 	loopstate.Getter
 	loopstate.Applier
 	SettingsGetSetter
-	ServersGetterSetter
 }
 
 type Loop struct {
 	statusManager loopstate.Manager
 	state         state.Manager
+	storage       Storage
 	// Fixed parameters
 	buildInfo     models.BuildInformation
 	versionInfo   bool
@@ -64,12 +64,17 @@ type firewallConfigurer interface {
 	firewall.PortAllower
 }
 
+type Storage interface {
+	FilterServers(provider string, selection settings.ServerSelection) (servers []models.Server, err error)
+	GetServerByName(provider, name string) (server models.Server, ok bool)
+}
+
 const (
 	defaultBackoffTime = 15 * time.Second
 )
 
 func NewLoop(vpnSettings settings.VPN, vpnInputPorts []uint16,
-	allServers models.AllServers, openvpnConf openvpn.Interface,
+	storage Storage, openvpnConf openvpn.Interface,
 	netLinker netlink.NetLinker, fw firewallConfigurer, routing routing.VPNGetter,
 	portForward portforward.StartStopper, starter command.Starter,
 	publicip publicip.Looper, dnsLooper dns.Looper,
@@ -81,11 +86,12 @@ func NewLoop(vpnSettings settings.VPN, vpnInputPorts []uint16,
 	stopped := make(chan struct{})
 
 	statusManager := loopstate.New(constants.Stopped, start, running, stop, stopped)
-	state := state.New(statusManager, vpnSettings, allServers)
+	state := state.New(statusManager, vpnSettings)
 
 	return &Loop{
 		statusManager: statusManager,
 		state:         state,
+		storage:       storage,
 		buildInfo:     buildInfo,
 		versionInfo:   versionInfo,
 		vpnInputPorts: vpnInputPorts,

internal/vpn/run.go

@@ -28,9 +28,9 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 	}
 
 	for ctx.Err() == nil {
-		settings, allServers := l.state.GetSettingsAndServers()
+		settings := l.state.GetSettings()
 
-		providerConf := provider.New(*settings.Provider.Name, allServers, time.Now)
+		providerConf := provider.New(*settings.Provider.Name, l.storage, time.Now)
 
 		portForwarding := *settings.Provider.PortForwarding.Enabled
 		var vpnRunner vpnRunner

internal/vpn/servers.go

@@ -1,16 +0,0 @@
-package vpn
-
-import (
-	"github.com/qdm12/gluetun/internal/models"
-	"github.com/qdm12/gluetun/internal/vpn/state"
-)
-
-type ServersGetterSetter = state.ServersGetterSetter
-
-func (l *Loop) GetServers() (servers models.AllServers) {
-	return l.state.GetServers()
-}
-
-func (l *Loop) SetServers(servers models.AllServers) {
-	l.state.SetServers(servers)
-}

internal/vpn/state/servers.go

@@ -1,20 +0,0 @@
-package state
-
-import "github.com/qdm12/gluetun/internal/models"
-
-type ServersGetterSetter interface {
-	GetServers() (servers models.AllServers)
-	SetServers(servers models.AllServers)
-}
-
-func (s *State) GetServers() (servers models.AllServers) {
-	s.allServersMu.RLock()
-	defer s.allServersMu.RUnlock()
-	return s.allServers
-}
-
-func (s *State) SetServers(servers models.AllServers) {
-	s.allServersMu.Lock()
-	defer s.allServersMu.Unlock()
-	s.allServers = servers
-}

internal/vpn/state/state.go

@@ -5,23 +5,18 @@ import (
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/loopstate"
-	"github.com/qdm12/gluetun/internal/models"
 )
 
 var _ Manager = (*State)(nil)
 
 type Manager interface {
 	SettingsGetSetter
-	ServersGetterSetter
-	GetSettingsAndServers() (vpn settings.VPN, allServers models.AllServers)
 }
 
-func New(statusApplier loopstate.Applier,
-	vpn settings.VPN, allServers models.AllServers) *State {
+func New(statusApplier loopstate.Applier, vpn settings.VPN) *State {
 	return &State{
 		statusApplier: statusApplier,
 		vpn:           vpn,
-		allServers:    allServers,
 	}
 }
 
@@ -30,18 +25,4 @@ type State struct {
 
 	vpn        settings.VPN
 	settingsMu sync.RWMutex
-
-	allServers   models.AllServers
-	allServersMu sync.RWMutex
-}
-
-func (s *State) GetSettingsAndServers() (vpn settings.VPN,
-	allServers models.AllServers) {
-	s.settingsMu.RLock()
-	s.allServersMu.RLock()
-	vpn = s.vpn
-	allServers = s.allServers
-	s.settingsMu.RUnlock()
-	s.allServersMu.RUnlock()
-	return vpn, allServers
 }