Loops and HTTP control server rework (#308)

- CRUD REST HTTP server
- `/v1` HTTP server prefix
- Retrocompatible with older routes (redirects to v1 or handles the requests directly)
- DNS, Updater and Openvpn refactored to have a REST-like state with new methods to change their states synchronously
- Openvpn, Unbound and Updater status, see #287

cmd/gluetun/main.go

@@ -217,15 +217,14 @@ func _main(background context.Context, args []string) int { //nolint:gocognit,go
 
 	go collectStreamLines(ctx, streamMerger, logger, signalTunnelReady)
 
-	openvpnLooper := openvpn.NewLooper(allSettings.VPNSP, allSettings.OpenVPN, uid, gid, allServers,
+	openvpnLooper := openvpn.NewLooper(allSettings.OpenVPN, uid, gid, allServers,
 		ovpnConf, firewallConf, routingConf, logger, httpClient, fileManager, streamMerger, cancel)
 	wg.Add(1)
 	// wait for restartOpenvpn
 	go openvpnLooper.Run(ctx, wg)
 
-	updaterOptions := updater.NewOptions("127.0.0.1")
-	updaterLooper := updater.NewLooper(updaterOptions, allSettings.UpdaterPeriod,
-		allServers, storage, openvpnLooper.SetAllServers, httpClient, logger)
+	updaterLooper := updater.NewLooper(allSettings.Updater,
+		allServers, storage, openvpnLooper.SetServers, httpClient, logger)
 	wg.Add(1)
 	// wait for updaterLooper.Restart() or its ticket launched with RunRestartTicker
 	go updaterLooper.Run(ctx, wg)
@@ -276,8 +275,9 @@ func _main(background context.Context, args []string) int { //nolint:gocognit,go
 	wg.Add(1)
 	go healthcheckServer.Run(ctx, wg)
 
-	// Start openvpn for the first time
-	openvpnLooper.Restart()
+	// Start openvpn for the first time in a blocking call
+	// until openvpn is launched
+	_, _ = openvpnLooper.SetStatus(constants.Running) // TODO option to disable with variable
 
 	signalsCh := make(chan os.Signal, 1)
 	signal.Notify(signalsCh,
@@ -401,7 +401,7 @@ func routeReadyEvents(ctx context.Context, wg *sync.WaitGroup, tunnelReadyCh, dn
 			tickerWg.Wait()
 			return
 		case <-tunnelReadyCh: // blocks until openvpn is connected
-			unboundLooper.Restart()
+			_, _ = unboundLooper.SetStatus(constants.Running)
 			restartTickerCancel() // stop previous restart tickers
 			tickerWg.Wait()
 			restartTickerContext, restartTickerCancel = context.WithCancel(ctx)

internal/cli/cli.go

@@ -83,7 +83,7 @@ func OpenvpnConfig() error {
 }
 
 func Update(args []string) error {
-	options := updater.Options{CLI: true}
+	options := settings.Updater{CLI: true}
 	var flushToFile bool
 	flagSet := flag.NewFlagSet("update", flag.ExitOnError)
 	flagSet.BoolVar(&flushToFile, "file", false, "Write results to /gluetun/servers.json (for end users)")

internal/constants/status.go

@@ -0,0 +1,14 @@
+package constants
+
+import (
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+const (
+	Starting  models.LoopStatus = "starting"
+	Running   models.LoopStatus = "running"
+	Stopping  models.LoopStatus = "stopping"
+	Stopped   models.LoopStatus = "stopped"
+	Crashed   models.LoopStatus = "crashed"
+	Completed models.LoopStatus = "completed"
+)

internal/dns/loop.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/settings"
 	"github.com/qdm12/golibs/command"
 	"github.com/qdm12/golibs/logging"
@@ -15,24 +16,24 @@ import (
 type Looper interface {
 	Run(ctx context.Context, wg *sync.WaitGroup, signalDNSReady func())
 	RunRestartTicker(ctx context.Context, wg *sync.WaitGroup)
-	Restart()
-	Start()
-	Stop()
+	GetStatus() (status models.LoopStatus)
+	SetStatus(status models.LoopStatus) (outcome string, err error)
 	GetSettings() (settings settings.DNS)
-	SetSettings(settings settings.DNS)
+	SetSettings(settings settings.DNS) (outcome string)
 }
 
 type looper struct {
+	state        state
 	conf         Configurator
-	settings      settings.DNS
-	settingsMutex sync.RWMutex
 	logger       logging.Logger
 	streamMerger command.StreamMerger
 	uid          int
 	gid          int
-	restart       chan struct{}
+	loopLock     sync.Mutex
 	start        chan struct{}
+	running      chan models.LoopStatus
 	stop         chan struct{}
+	stopped      chan struct{}
 	updateTicker chan struct{}
 	timeNow      func() time.Time
 	timeSince    func(time.Time) time.Duration
@@ -41,54 +42,25 @@ type looper struct {
 func NewLooper(conf Configurator, settings settings.DNS, logger logging.Logger,
 	streamMerger command.StreamMerger, uid, gid int) Looper {
 	return &looper{
-		conf:         conf,
+		state: state{
+			status:   constants.Stopped,
 			settings: settings,
+		},
+		conf:         conf,
 		logger:       logger.WithPrefix("dns over tls: "),
 		uid:          uid,
 		gid:          gid,
 		streamMerger: streamMerger,
-		restart:      make(chan struct{}),
 		start:        make(chan struct{}),
+		running:      make(chan models.LoopStatus),
 		stop:         make(chan struct{}),
+		stopped:      make(chan struct{}),
 		updateTicker: make(chan struct{}),
 		timeNow:      time.Now,
 		timeSince:    time.Since,
 	}
 }
 
-func (l *looper) Restart() { l.restart <- struct{}{} }
-func (l *looper) Start()   { l.start <- struct{}{} }
-func (l *looper) Stop()    { l.stop <- struct{}{} }
-
-func (l *looper) GetSettings() (settings settings.DNS) {
-	l.settingsMutex.RLock()
-	defer l.settingsMutex.RUnlock()
-	return l.settings
-}
-
-func (l *looper) SetSettings(settings settings.DNS) {
-	l.settingsMutex.Lock()
-	defer l.settingsMutex.Unlock()
-	updatePeriodDiffers := l.settings.UpdatePeriod != settings.UpdatePeriod
-	l.settings = settings
-	l.settingsMutex.Unlock()
-	if updatePeriodDiffers {
-		l.updateTicker <- struct{}{}
-	}
-}
-
-func (l *looper) isEnabled() bool {
-	l.settingsMutex.RLock()
-	defer l.settingsMutex.RUnlock()
-	return l.settings.Enabled
-}
-
-func (l *looper) setEnabled(enabled bool) {
-	l.settingsMutex.Lock()
-	defer l.settingsMutex.Unlock()
-	l.settings.Enabled = enabled
-}
-
 func (l *looper) logAndWait(ctx context.Context, err error) {
 	l.logger.Warn(err)
 	l.logger.Info("attempting restart in 10 seconds")
@@ -103,96 +75,42 @@ func (l *looper) logAndWait(ctx context.Context, err error) {
 	}
 }
 
-func (l *looper) waitForFirstStart(ctx context.Context, signalDNSReady func()) {
-	for {
-		select {
-		case <-l.stop:
-			l.setEnabled(false)
-			l.logger.Info("not started yet")
-		case <-l.restart:
-			if l.isEnabled() {
-				return
-			}
-			signalDNSReady()
-			l.logger.Info("not restarting because disabled")
-		case <-l.start:
-			l.setEnabled(true)
-			return
-		case <-ctx.Done():
-			return
-		}
-	}
-}
-
-func (l *looper) waitForSubsequentStart(ctx context.Context, unboundCancel context.CancelFunc) {
-	if l.isEnabled() {
-		return
-	}
-	for {
-		// wait for a signal to re-enable
-		select {
-		case <-l.stop:
-			l.logger.Info("already disabled")
-		case <-l.restart:
-			if !l.isEnabled() {
-				l.logger.Info("not restarting because disabled")
-			} else {
-				return
-			}
-		case <-l.start:
-			l.setEnabled(true)
-			return
-		case <-ctx.Done():
-			unboundCancel()
-			return
-		}
-	}
-}
-
 func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup, signalDNSReady func()) {
 	defer wg.Done()
+
 	const fallback = false
-	l.useUnencryptedDNS(fallback)
-	l.waitForFirstStart(ctx, signalDNSReady)
-	if ctx.Err() != nil {
+	l.useUnencryptedDNS(fallback) // TODO remove? Use default DNS by default for Docker resolution?
+
+	select {
+	case <-l.start:
+	case <-ctx.Done():
 		return
 	}
+
 	defer l.logger.Warn("loop exited")
 
-	var unboundCtx context.Context
-	var unboundCancel context.CancelFunc = func() {}
-	var waitError chan error
-	triggeredRestart := false
-	l.setEnabled(true)
 	for ctx.Err() == nil {
-		l.waitForSubsequentStart(ctx, unboundCancel)
+		err := l.updateFiles(ctx)
+		if err == nil {
+			break
+		}
+		l.state.setStatusWithLock(constants.Crashed)
+		l.logAndWait(ctx, err)
+	}
 
+	crashed := false
+
+	for ctx.Err() == nil {
 		settings := l.GetSettings()
 
-		// Setup
-		if err := l.conf.DownloadRootHints(ctx, l.uid, l.gid); err != nil {
-			l.logAndWait(ctx, err)
-			continue
-		}
-		if err := l.conf.DownloadRootKey(ctx, l.uid, l.gid); err != nil {
-			l.logAndWait(ctx, err)
-			continue
-		}
-		if err := l.conf.MakeUnboundConf(ctx, settings, l.uid, l.gid); err != nil {
-			l.logAndWait(ctx, err)
-			continue
-		}
-
-		if triggeredRestart {
-			triggeredRestart = false
-			unboundCancel()
-			<-waitError
-			close(waitError)
-		}
-		unboundCtx, unboundCancel = context.WithCancel(context.Background())
+		unboundCtx, unboundCancel := context.WithCancel(context.Background())
 		stream, waitFn, err := l.conf.Start(unboundCtx, settings.VerbosityDetailsLevel)
 		if err != nil {
 			unboundCancel()
+			if !crashed {
+				l.running <- constants.Crashed
+			}
+			crashed = true
 			const fallback = true
 			l.useUnencryptedDNS(fallback)
 			l.logAndWait(ctx, err)
@@ -201,23 +119,37 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup, signalDNSReady fun
 
 		// Started successfully
 		go l.streamMerger.Merge(unboundCtx, stream, command.MergeName("unbound"))
+
 		l.conf.UseDNSInternally(net.IP{127, 0, 0, 1})                                                  // use Unbound
 		if err := l.conf.UseDNSSystemWide(net.IP{127, 0, 0, 1}, settings.KeepNameserver); err != nil { // use Unbound
 			l.logger.Error(err)
 		}
+
 		if err := l.conf.WaitForUnbound(); err != nil {
+			if !crashed {
+				l.running <- constants.Crashed
+				crashed = true
+			}
 			unboundCancel()
 			const fallback = true
 			l.useUnencryptedDNS(fallback)
 			l.logAndWait(ctx, err)
 			continue
 		}
-		waitError = make(chan error)
+
+		waitError := make(chan error)
 		go func() {
 			err := waitFn() // blocking
 			waitError <- err
 		}()
+
 		l.logger.Info("DNS over TLS is ready")
+		if !crashed {
+			l.running <- constants.Running
+			crashed = false
+		} else {
+			l.state.setStatusWithLock(constants.Running)
+		}
 		signalDNSReady()
 
 		stayHere := true
@@ -229,32 +161,29 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup, signalDNSReady fun
 				<-waitError
 				close(waitError)
 				return
-			case <-l.restart: // triggered restart
-				l.logger.Info("restarting")
-				// unboundCancel occurs next loop run when the setup is complete
-				triggeredRestart = true
-				stayHere = false
-			case <-l.start:
-				l.logger.Info("already started")
 			case <-l.stop:
 				l.logger.Info("stopping")
+				const fallback = false
+				l.useUnencryptedDNS(fallback)
 				unboundCancel()
 				<-waitError
-				close(waitError)
-				l.setEnabled(false)
+				l.stopped <- struct{}{}
+			case <-l.start:
+				l.logger.Info("starting")
 				stayHere = false
 			case err := <-waitError: // unexpected error
-				close(waitError)
 				unboundCancel()
+				l.state.setStatusWithLock(constants.Crashed)
 				const fallback = true
 				l.useUnencryptedDNS(fallback)
 				l.logAndWait(ctx, err)
 				stayHere = false
 			}
 		}
-	}
+		close(waitError)
 		unboundCancel()
 	}
+}
 
 func (l *looper) useUnencryptedDNS(fallback bool) {
 	settings := l.GetSettings()
@@ -279,7 +208,11 @@ func (l *looper) useUnencryptedDNS(fallback bool) {
 		data := constants.DNSProviderMapping()[provider]
 		for _, targetIP = range data.IPs {
 			if targetIP.To4() != nil {
+				if fallback {
 					l.logger.Info("falling back on plaintext DNS at address %s", targetIP)
+				} else {
+					l.logger.Info("using plaintext DNS at address %s", targetIP)
+				}
 				l.conf.UseDNSInternally(targetIP)
 				if err := l.conf.UseDNSSystemWide(targetIP, settings.KeepNameserver); err != nil {
 					l.logger.Error(err)
@@ -314,7 +247,20 @@ func (l *looper) RunRestartTicker(ctx context.Context, wg *sync.WaitGroup) {
 			return
 		case <-timer.C:
 			lastTick = l.timeNow()
-			l.restart <- struct{}{}
+
+			status := l.GetStatus()
+			if status == constants.Running {
+				if err := l.updateFiles(ctx); err != nil {
+					l.state.setStatusWithLock(constants.Crashed)
+					l.logger.Error(err)
+					l.logger.Warn("skipping Unbound restart due to failed files update")
+					continue
+				}
+			}
+
+			_, _ = l.SetStatus(constants.Stopped)
+			_, _ = l.SetStatus(constants.Running)
+
 			settings := l.GetSettings()
 			timer.Reset(settings.UpdatePeriod)
 		case <-l.updateTicker:
@@ -337,3 +283,17 @@ func (l *looper) RunRestartTicker(ctx context.Context, wg *sync.WaitGroup) {
 		}
 	}
 }
+
+func (l *looper) updateFiles(ctx context.Context) (err error) {
+	if err := l.conf.DownloadRootHints(ctx, l.uid, l.gid); err != nil {
+		return err
+	}
+	if err := l.conf.DownloadRootKey(ctx, l.uid, l.gid); err != nil {
+		return err
+	}
+	settings := l.GetSettings()
+	if err := l.conf.MakeUnboundConf(ctx, settings, l.uid, l.gid); err != nil {
+		return err
+	}
+	return nil
+}

internal/dns/state.go

@@ -0,0 +1,96 @@
+package dns
+
+import (
+	"fmt"
+	"reflect"
+	"sync"
+
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/settings"
+)
+
+type state struct {
+	status     models.LoopStatus
+	settings   settings.DNS
+	statusMu   sync.RWMutex
+	settingsMu sync.RWMutex
+}
+
+func (s *state) setStatusWithLock(status models.LoopStatus) {
+	s.statusMu.Lock()
+	defer s.statusMu.Unlock()
+	s.status = status
+}
+
+func (l *looper) GetStatus() (status models.LoopStatus) {
+	l.state.statusMu.RLock()
+	defer l.state.statusMu.RUnlock()
+	return l.state.status
+}
+
+func (l *looper) SetStatus(status models.LoopStatus) (outcome string, err error) {
+	l.state.statusMu.Lock()
+	defer l.state.statusMu.Unlock()
+	existingStatus := l.state.status
+
+	switch status {
+	case constants.Running:
+		switch existingStatus {
+		case constants.Starting, constants.Running, constants.Stopping, constants.Crashed:
+			return fmt.Sprintf("already %s", existingStatus), nil
+		}
+		l.loopLock.Lock()
+		defer l.loopLock.Unlock()
+		l.state.status = constants.Starting
+		l.state.statusMu.Unlock()
+		l.start <- struct{}{}
+		newStatus := <-l.running
+		l.state.statusMu.Lock()
+		l.state.status = newStatus
+		return newStatus.String(), nil
+	case constants.Stopped:
+		switch existingStatus {
+		case constants.Starting, constants.Stopping, constants.Stopped, constants.Crashed:
+			return fmt.Sprintf("already %s", existingStatus), nil
+		}
+		l.loopLock.Lock()
+		defer l.loopLock.Unlock()
+		l.state.status = constants.Stopping
+		l.state.statusMu.Unlock()
+		l.stop <- struct{}{}
+		<-l.stopped
+		l.state.statusMu.Lock()
+		l.state.status = constants.Stopped
+		return status.String(), nil
+	default:
+		return "", fmt.Errorf("status %q can only be %q or %q",
+			status, constants.Running, constants.Stopped)
+	}
+}
+
+func (l *looper) GetSettings() (settings settings.DNS) {
+	l.state.settingsMu.RLock()
+	defer l.state.settingsMu.RUnlock()
+	return l.state.settings
+}
+
+func (l *looper) SetSettings(settings settings.DNS) (outcome string) {
+	l.state.settingsMu.Lock()
+	settingsUnchanged := reflect.DeepEqual(l.state.settings, settings)
+	if settingsUnchanged {
+		l.state.settingsMu.Unlock()
+		return "settings left unchanged"
+	}
+	tempSettings := l.state.settings
+	tempSettings.UpdatePeriod = settings.UpdatePeriod
+	onlyUpdatePeriodChanged := reflect.DeepEqual(tempSettings, settings)
+	l.state.settings = settings
+	if onlyUpdatePeriodChanged {
+		l.updateTicker <- struct{}{}
+		return "update period changed"
+	}
+	_, _ = l.SetStatus(constants.Stopped)
+	outcome, _ = l.SetStatus(constants.Running)
+	return outcome
+}

internal/models/alias.go

@@ -20,8 +20,14 @@ type (
 	VPNProvider string
 	// NetworkProtocol contains the network protocol to be used to communicate with the VPN servers.
 	NetworkProtocol string
+	// Loop status such as stopped or running.
+	LoopStatus string
 )
 
+func (ls LoopStatus) String() string {
+	return string(ls)
+}
+
 func marshalJSONString(s string) (data []byte, err error) {
 	return []byte(fmt.Sprintf("%q", s)), nil
 }

internal/models/build.go

@@ -3,5 +3,5 @@ package models
 type BuildInformation struct {
 	Version   string `json:"version"`
 	Commit    string `json:"commit"`
-	BuildDate string `json:"buildDate"`
+	BuildDate string `json:"build_date"`
 }

internal/models/openvpn.go

@@ -1,6 +1,8 @@
 package models
 
-import "net"
+import (
+	"net"
+)
 
 type OpenVPNConnection struct {
 	IP       net.IP

internal/models/selection.go

@@ -9,15 +9,15 @@ import (
 // ProviderSettings contains settings specific to a VPN provider.
 type ProviderSettings struct {
 	Name               VPNProvider        `json:"name"`
-	ServerSelection    ServerSelection    `json:"serverSelection"`
-	ExtraConfigOptions ExtraConfigOptions `json:"extraConfig"`
-	PortForwarding     PortForwarding     `json:"portForwarding"`
+	ServerSelection    ServerSelection    `json:"server_selection"`
+	ExtraConfigOptions ExtraConfigOptions `json:"extra_config"`
+	PortForwarding     PortForwarding     `json:"port_forwarding"`
 }
 
 type ServerSelection struct {
 	// Common
-	Protocol NetworkProtocol `json:"networkProtocol"`
-	TargetIP net.IP          `json:"targetIP,omitempty"`
+	Protocol NetworkProtocol `json:"network_protocol"`
+	TargetIP net.IP          `json:"target_ip,omitempty"`
 
 	// Cyberghost, PIA, Surfshark, Windscribe, Vyprvpn, NordVPN
 	Regions []string `json:"regions"`
@@ -34,20 +34,20 @@ type ServerSelection struct {
 	Owned bool     `json:"owned"`
 
 	// Mullvad, Windscribe
-	CustomPort uint16 `json:"customPort"`
+	CustomPort uint16 `json:"custom_port"`
 
 	// NordVPN
 	Numbers []uint16 `json:"numbers"`
 
 	// PIA
-	EncryptionPreset string `json:"encryptionPreset"`
+	EncryptionPreset string `json:"encryption_preset"`
 }
 
 type ExtraConfigOptions struct {
 	ClientCertificate string `json:"-"`                 // Cyberghost
 	ClientKey         string `json:"-"`                 // Cyberghost
-	EncryptionPreset  string `json:"encryptionPreset"` // PIA
-	OpenVPNIPv6       bool   `json:"openvpnIPv6"`      // Mullvad
+	EncryptionPreset  string `json:"encryption_preset"` // PIA
+	OpenVPNIPv6       bool   `json:"openvpn_ipv6"`      // Mullvad
 }
 
 // PortForwarding contains settings for port forwarding.

internal/openvpn/loop.go

@@ -20,23 +20,18 @@ import (
 
 type Looper interface {
 	Run(ctx context.Context, wg *sync.WaitGroup)
-	Restart()
-	PortForward(vpnGatewayIP net.IP)
+	GetStatus() (status models.LoopStatus)
+	SetStatus(status models.LoopStatus) (outcome string, err error)
 	GetSettings() (settings settings.OpenVPN)
-	SetSettings(settings settings.OpenVPN)
-	GetPortForwarded() (portForwarded uint16)
-	SetAllServers(allServers models.AllServers)
+	SetSettings(settings settings.OpenVPN) (outcome string)
+	GetServers() (servers models.AllServers)
+	SetServers(servers models.AllServers)
+	GetPortForwarded() (port uint16)
+	PortForward(vpnGatewayIP net.IP)
 }
 
 type looper struct {
-	// Variable parameters
-	provider           models.VPNProvider
-	settings           settings.OpenVPN
-	settingsMutex      sync.RWMutex
-	portForwarded      uint16
-	portForwardedMutex sync.RWMutex
-	allServers         models.AllServers
-	allServersMutex    sync.RWMutex
+	state state
 	// Fixed parameters
 	uid int
 	gid int
@@ -50,22 +45,27 @@ type looper struct {
 	fileManager      files.FileManager
 	streamMerger     command.StreamMerger
 	cancel           context.CancelFunc
-	// Internal channels
-	restart            chan struct{}
+	// Internal channels and locks
+	loopLock           sync.Mutex
+	running            chan models.LoopStatus
+	stop, stopped      chan struct{}
+	start              chan struct{}
 	portForwardSignals chan net.IP
 }
 
-func NewLooper(provider models.VPNProvider, settings settings.OpenVPN,
+func NewLooper(settings settings.OpenVPN,
 	uid, gid int, allServers models.AllServers,
 	conf Configurator, fw firewall.Configurator, routing routing.Routing,
 	logger logging.Logger, client *http.Client, fileManager files.FileManager,
 	streamMerger command.StreamMerger, cancel context.CancelFunc) Looper {
 	return &looper{
-		provider:           provider,
+		state: state{
+			status:     constants.Stopped,
 			settings:   settings,
+			allServers: allServers,
+		},
 		uid:                uid,
 		gid:                gid,
-		allServers:         allServers,
 		conf:               conf,
 		fw:                 fw,
 		routing:            routing,
@@ -75,46 +75,29 @@ func NewLooper(provider models.VPNProvider, settings settings.OpenVPN,
 		fileManager:        fileManager,
 		streamMerger:       streamMerger,
 		cancel:             cancel,
-		restart:            make(chan struct{}),
+		start:              make(chan struct{}),
+		running:            make(chan models.LoopStatus),
+		stop:               make(chan struct{}),
+		stopped:            make(chan struct{}),
 		portForwardSignals: make(chan net.IP),
 	}
 }
 
-func (l *looper) Restart()                      { l.restart <- struct{}{} }
 func (l *looper) PortForward(vpnGateway net.IP) { l.portForwardSignals <- vpnGateway }
 
-func (l *looper) GetSettings() (settings settings.OpenVPN) {
-	l.settingsMutex.RLock()
-	defer l.settingsMutex.RUnlock()
-	return l.settings
-}
-
-func (l *looper) SetSettings(settings settings.OpenVPN) {
-	l.settingsMutex.Lock()
-	defer l.settingsMutex.Unlock()
-	l.settings = settings
-}
-
-func (l *looper) SetAllServers(allServers models.AllServers) {
-	l.allServersMutex.Lock()
-	defer l.allServersMutex.Unlock()
-	l.allServers = allServers
-}
-
 func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
 	defer wg.Done()
+	crashed := false
 	select {
-	case <-l.restart:
+	case <-l.start:
 	case <-ctx.Done():
 		return
 	}
 	defer l.logger.Warn("loop exited")
 
 	for ctx.Err() == nil {
-		settings := l.GetSettings()
-		l.allServersMutex.RLock()
-		providerConf := provider.New(l.provider, l.allServers, time.Now)
-		l.allServersMutex.RUnlock()
+		settings, allServers := l.state.getSettingsAndServers()
+		providerConf := provider.New(settings.Provider.Name, allServers, time.Now)
 		connection, err := providerConf.GetOpenVPNConnection(settings.Provider.ServerSelection)
 		if err != nil {
 			l.logger.Error(err)
@@ -155,6 +138,10 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
 		stream, waitFn, err := l.conf.Start(openvpnCtx)
 		if err != nil {
 			openvpnCancel()
+			if !crashed {
+				l.running <- constants.Crashed
+				crashed = true
+			}
 			l.logAndWait(ctx, err)
 			continue
 		}
@@ -179,6 +166,16 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
 			err := waitFn() // blocking
 			waitError <- err
 		}()
+
+		if !crashed {
+			l.running <- constants.Running
+			crashed = false
+		} else {
+			l.state.setStatusWithLock(constants.Running)
+		}
+
+		stayHere := true
+		for stayHere {
 			select {
 			case <-ctx.Done():
 				l.logger.Warn("context canceled: exiting loop")
@@ -186,17 +183,25 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
 				<-waitError
 				close(waitError)
 				return
-		case <-l.restart: // triggered restart
-			l.logger.Info("restarting")
+			case <-l.stop:
+				l.logger.Info("stopping")
 				openvpnCancel()
 				<-waitError
-			close(waitError)
+				l.stopped <- struct{}{}
+			case <-l.start:
+				l.logger.Info("starting")
+				stayHere = false
 			case err := <-waitError: // unexpected error
 				openvpnCancel()
-			close(waitError)
+				l.state.setStatusWithLock(constants.Crashed)
 				l.logAndWait(ctx, err)
+				crashed = true
+				stayHere = false
 			}
 		}
+		close(waitError)
+		openvpnCancel() // just for the linter
+	}
 }
 
 func (l *looper) logAndWait(ctx context.Context, err error) {
@@ -218,24 +223,21 @@ func (l *looper) logAndWait(ctx context.Context, err error) {
 func (l *looper) portForward(ctx context.Context, wg *sync.WaitGroup,
 	providerConf provider.Provider, client *http.Client, gateway net.IP) {
 	defer wg.Done()
-	settings := l.GetSettings()
+	l.state.portForwardedMu.RLock()
+	settings := l.state.settings
+	l.state.portForwardedMu.RUnlock()
 	if !settings.Provider.PortForwarding.Enabled {
 		return
 	}
 	syncState := func(port uint16) (pfFilepath models.Filepath) {
-		l.portForwardedMutex.Lock()
-		l.portForwarded = port
-		l.portForwardedMutex.Unlock()
-		settings := l.GetSettings()
+		l.state.portForwardedMu.Lock()
+		defer l.state.portForwardedMu.Unlock()
+		l.state.portForwarded = port
+		l.state.settingsMu.RLock()
+		defer l.state.settingsMu.RUnlock()
 		return settings.Provider.PortForwarding.Filepath
 	}
 	providerConf.PortForward(ctx,
 		client, l.fileManager, l.pfLogger,
 		gateway, l.fw, syncState)
 }
-
-func (l *looper) GetPortForwarded() (portForwarded uint16) {
-	l.portForwardedMutex.RLock()
-	defer l.portForwardedMutex.RUnlock()
-	return l.portForwarded
-}

internal/openvpn/state.go

@@ -0,0 +1,121 @@
+package openvpn
+
+import (
+	"fmt"
+	"reflect"
+	"sync"
+
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/settings"
+)
+
+type state struct {
+	status          models.LoopStatus
+	settings        settings.OpenVPN
+	allServers      models.AllServers
+	portForwarded   uint16
+	statusMu        sync.RWMutex
+	settingsMu      sync.RWMutex
+	allServersMu    sync.RWMutex
+	portForwardedMu sync.RWMutex
+}
+
+func (s *state) setStatusWithLock(status models.LoopStatus) {
+	s.statusMu.Lock()
+	defer s.statusMu.Unlock()
+	s.status = status
+}
+
+func (s *state) getSettingsAndServers() (settings settings.OpenVPN, allServers models.AllServers) {
+	s.settingsMu.RLock()
+	s.allServersMu.RLock()
+	settings = s.settings
+	allServers = s.allServers
+	s.settingsMu.RLock()
+	s.allServersMu.RLock()
+	return settings, allServers
+}
+
+func (l *looper) GetStatus() (status models.LoopStatus) {
+	l.state.statusMu.RLock()
+	defer l.state.statusMu.RUnlock()
+	return l.state.status
+}
+
+func (l *looper) SetStatus(status models.LoopStatus) (outcome string, err error) {
+	l.state.statusMu.Lock()
+	defer l.state.statusMu.Unlock()
+	existingStatus := l.state.status
+
+	switch status {
+	case constants.Running:
+		switch existingStatus {
+		case constants.Starting, constants.Running, constants.Stopping, constants.Crashed:
+			return fmt.Sprintf("already %s", existingStatus), nil
+		}
+		l.loopLock.Lock()
+		defer l.loopLock.Unlock()
+		l.state.status = constants.Starting
+		l.state.statusMu.Unlock()
+		l.start <- struct{}{}
+		newStatus := <-l.running
+		l.state.statusMu.Lock()
+		l.state.status = newStatus
+		return newStatus.String(), nil
+	case constants.Stopped:
+		switch existingStatus {
+		case constants.Starting, constants.Stopping, constants.Stopped, constants.Crashed:
+			return fmt.Sprintf("already %s", existingStatus), nil
+		}
+		l.loopLock.Lock()
+		defer l.loopLock.Unlock()
+		l.state.status = constants.Stopping
+		l.state.statusMu.Unlock()
+		l.stop <- struct{}{}
+		<-l.stopped
+		l.state.statusMu.Lock()
+		l.state.status = constants.Stopped
+		return status.String(), nil
+	default:
+		return "", fmt.Errorf("status %q can only be %q or %q",
+			status, constants.Running, constants.Stopped)
+	}
+}
+
+func (l *looper) GetSettings() (settings settings.OpenVPN) {
+	l.state.settingsMu.RLock()
+	defer l.state.settingsMu.RUnlock()
+	return l.state.settings
+}
+
+func (l *looper) SetSettings(settings settings.OpenVPN) (outcome string) {
+	l.state.settingsMu.Lock()
+	settingsUnchanged := reflect.DeepEqual(l.state.settings, settings)
+	if settingsUnchanged {
+		l.state.settingsMu.Unlock()
+		return "settings left unchanged"
+	}
+	l.state.settings = settings
+	_, _ = l.SetStatus(constants.Stopped)
+	outcome, _ = l.SetStatus(constants.Running)
+	return outcome
+}
+
+func (l *looper) GetServers() (servers models.AllServers) {
+	l.state.allServersMu.RLock()
+	defer l.state.allServersMu.RUnlock()
+	return l.state.allServers
+}
+
+func (l *looper) SetServers(servers models.AllServers) {
+	l.state.allServersMu.Lock()
+	defer l.state.allServersMu.Unlock()
+	l.state.allServers = servers
+}
+
+func (l *looper) GetPortForwarded() (port uint16) {
+	l.state.portForwardedMu.RLock()
+	defer l.state.portForwardedMu.RUnlock()
+	return port
+}

internal/params/dns.go

@@ -130,8 +130,8 @@ func (r *reader) GetDNSOverTLSPrivateAddresses() (privateAddresses []string, err
 	return privateAddresses, nil
 }
 
-// GetDNSOverTLSIPv6 obtains if Unbound should resolve ipv6 addresses using ipv6 DNS over TLS
-//  servers from the environment variable DOT_IPV6.
+// GetDNSOverTLSIPv6 obtains if Unbound should resolve ipv6 addresses using
+// ipv6 DNS over TLS from the environment variable DOT_IPV6.
 func (r *reader) GetDNSOverTLSIPv6() (ipv6 bool, err error) {
 	return r.envParams.GetOnOff("DOT_IPV6", libparams.Default("off"))
 }

internal/server/dns.go

@@ -0,0 +1,76 @@
+//nolint:dupl
+package server
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/dns"
+	"github.com/qdm12/golibs/logging"
+)
+
+func newDNSHandler(looper dns.Looper, logger logging.Logger) http.Handler {
+	return &dnsHandler{
+		looper: looper,
+		logger: logger,
+	}
+}
+
+type dnsHandler struct {
+	looper dns.Looper
+	logger logging.Logger
+}
+
+func (h *dnsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	r.RequestURI = strings.TrimPrefix(r.RequestURI, "/dns")
+	switch r.RequestURI {
+	case "/status": //nolint:goconst
+		switch r.Method {
+		case http.MethodGet:
+			h.getStatus(w)
+		case http.MethodPut:
+			h.setStatus(w, r)
+		default:
+			http.Error(w, "", http.StatusNotFound)
+		}
+	default:
+		http.Error(w, "", http.StatusNotFound)
+	}
+}
+
+func (h *dnsHandler) getStatus(w http.ResponseWriter) {
+	status := h.looper.GetStatus()
+	encoder := json.NewEncoder(w)
+	data := statusWrapper{Status: string(status)}
+	if err := encoder.Encode(data); err != nil {
+		h.logger.Warn(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+}
+
+func (h *dnsHandler) setStatus(w http.ResponseWriter, r *http.Request) {
+	decoder := json.NewDecoder(r.Body)
+	var data statusWrapper
+	if err := decoder.Decode(&data); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	status, err := data.getStatus()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	outcome, err := h.looper.SetStatus(status)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	encoder := json.NewEncoder(w)
+	if err := encoder.Encode(outcomeWrapper{Outcome: outcome}); err != nil {
+		h.logger.Warn(err)
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+		return
+	}
+}

internal/server/handler.go

@@ -1,8 +1,8 @@
 package server
 
 import (
-	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/qdm12/gluetun/internal/dns"
 	"github.com/qdm12/gluetun/internal/models"
@@ -17,54 +17,33 @@ func newHandler(logger logging.Logger, logging bool,
 	unboundLooper dns.Looper,
 	updaterLooper updater.Looper,
 ) http.Handler {
-	return &handler{
-		logger:        logger,
-		logging:       logging,
-		buildInfo:     buildInfo,
-		openvpnLooper: openvpnLooper,
-		unboundLooper: unboundLooper,
-		updaterLooper: updaterLooper,
-	}
+	handler := &handler{}
+
+	openvpn := newOpenvpnHandler(openvpnLooper, logger)
+	dns := newDNSHandler(unboundLooper, logger)
+	updater := newUpdaterHandler(updaterLooper, logger)
+
+	handler.v0 = newHandlerV0(logger, openvpnLooper, unboundLooper, updaterLooper)
+	handler.v1 = newHandlerV1(logger, buildInfo, openvpn, dns, updater)
+
+	handlerWithLog := withLogMiddleware(handler, logger, logging)
+	handler.setLogEnabled = handlerWithLog.setEnabled
+
+	return handlerWithLog
 }
 
 type handler struct {
-	logger        logging.Logger
-	logging       bool
-	buildInfo     models.BuildInformation
-	openvpnLooper openvpn.Looper
-	unboundLooper dns.Looper
-	updaterLooper updater.Looper
+	v0            http.Handler
+	v1            http.Handler
+	setLogEnabled func(enabled bool)
 }
 
-func (h *handler) ServeHTTP(responseWriter http.ResponseWriter, request *http.Request) {
-	if h.logging {
-		h.logger.Info("HTTP %s %s", request.Method, request.RequestURI)
-	}
-	switch request.Method {
-	case http.MethodGet:
-		switch request.RequestURI {
-		case "/version":
-			h.getVersion(responseWriter)
-			responseWriter.WriteHeader(http.StatusOK)
-		case "/openvpn/actions/restart":
-			h.openvpnLooper.Restart()
-			responseWriter.WriteHeader(http.StatusOK)
-		case "/unbound/actions/restart":
-			h.unboundLooper.Restart()
-			responseWriter.WriteHeader(http.StatusOK)
-		case "/openvpn/portforwarded":
-			h.getPortForwarded(responseWriter)
-		case "/openvpn/settings":
-			h.getOpenvpnSettings(responseWriter)
-		case "/updater/restart":
-			h.updaterLooper.Restart()
-			responseWriter.WriteHeader(http.StatusOK)
-		default:
-			errString := fmt.Sprintf("Nothing here for %s %s", request.Method, request.RequestURI)
-			http.Error(responseWriter, errString, http.StatusBadRequest)
-		}
-	default:
-		errString := fmt.Sprintf("Nothing here for %s %s", request.Method, request.RequestURI)
-		http.Error(responseWriter, errString, http.StatusBadRequest)
+func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	r.RequestURI = strings.TrimSuffix(r.RequestURI, "/")
+	if !strings.HasPrefix(r.RequestURI, "/v1/") && r.RequestURI != "/v1" {
+		h.v0.ServeHTTP(w, r)
+		return
 	}
+	r.RequestURI = strings.TrimPrefix(r.RequestURI, "/v1")
+	h.v1.ServeHTTP(w, r)
 }

internal/server/handlerv0.go

@@ -0,0 +1,69 @@
+package server
+
+import (
+	"net/http"
+
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/dns"
+	"github.com/qdm12/gluetun/internal/openvpn"
+	"github.com/qdm12/gluetun/internal/updater"
+	"github.com/qdm12/golibs/logging"
+)
+
+func newHandlerV0(logger logging.Logger,
+	openvpn openvpn.Looper, dns dns.Looper, updater updater.Looper) http.Handler {
+	return &handlerV0{
+		logger:  logger,
+		openvpn: openvpn,
+		dns:     dns,
+		updater: updater,
+	}
+}
+
+type handlerV0 struct {
+	logger  logging.Logger
+	openvpn openvpn.Looper
+	dns     dns.Looper
+	updater updater.Looper
+}
+
+func (h *handlerV0) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "unversioned API: only supports GET method", http.StatusNotFound)
+		return
+	}
+	switch r.RequestURI {
+	case "/version":
+		http.Redirect(w, r, "/v1/version", http.StatusPermanentRedirect)
+	case "/openvpn/actions/restart":
+		outcome, _ := h.openvpn.SetStatus(constants.Stopped)
+		h.logger.Info("openvpn: %s", outcome)
+		outcome, _ = h.openvpn.SetStatus(constants.Running)
+		h.logger.Info("openvpn: %s", outcome)
+		if _, err := w.Write([]byte("openvpn restarted, please consider using the /v1/ API in the future.")); err != nil {
+			h.logger.Warn(err)
+		}
+	case "/unbound/actions/restart":
+		outcome, _ := h.dns.SetStatus(constants.Stopped)
+		h.logger.Info("dns: %s", outcome)
+		outcome, _ = h.dns.SetStatus(constants.Running)
+		h.logger.Info("dns: %s", outcome)
+		if _, err := w.Write([]byte("dns restarted, please consider using the /v1/ API in the future.")); err != nil {
+			h.logger.Warn(err)
+		}
+	case "/openvpn/portforwarded":
+		http.Redirect(w, r, "/v1/openvpn/portforwarded", http.StatusPermanentRedirect)
+	case "/openvpn/settings":
+		http.Redirect(w, r, "/v1/openvpn/settings", http.StatusPermanentRedirect)
+	case "/updater/restart":
+		outcome, _ := h.updater.SetStatus(constants.Stopped)
+		h.logger.Info("updater: %s", outcome)
+		outcome, _ = h.updater.SetStatus(constants.Running)
+		h.logger.Info("updater: %s", outcome)
+		if _, err := w.Write([]byte("updater restarted, please consider using the /v1/ API in the future.")); err != nil {
+			h.logger.Warn(err)
+		}
+	default:
+		http.Error(w, "unversioned API: requested URI not found", http.StatusNotFound)
+	}
+}

internal/server/handlerv1.go

@@ -0,0 +1,58 @@
+package server
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/golibs/logging"
+)
+
+func newHandlerV1(logger logging.Logger, buildInfo models.BuildInformation,
+	openvpn, dns, updater http.Handler) http.Handler {
+	return &handlerV1{
+		logger:    logger,
+		buildInfo: buildInfo,
+		openvpn:   openvpn,
+		dns:       dns,
+		updater:   updater,
+	}
+}
+
+type handlerV1 struct {
+	logger    logging.Logger
+	buildInfo models.BuildInformation
+	openvpn   http.Handler
+	dns       http.Handler
+	updater   http.Handler
+}
+
+func (h *handlerV1) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	switch {
+	case r.RequestURI == "/version" && r.Method == http.MethodGet:
+		h.getVersion(w)
+	case strings.HasPrefix(r.RequestURI, "/openvpn"):
+		h.openvpn.ServeHTTP(w, r)
+	case strings.HasPrefix(r.RequestURI, "/dns"):
+		h.dns.ServeHTTP(w, r)
+	case strings.HasPrefix(r.RequestURI, "/updater"):
+		h.updater.ServeHTTP(w, r)
+	default:
+		errString := fmt.Sprintf("%s %s not found", r.Method, r.RequestURI)
+		http.Error(w, errString, http.StatusNotFound)
+	}
+}
+
+func (h *handlerV1) getVersion(w http.ResponseWriter) {
+	data, err := json.Marshal(h.buildInfo)
+	if err != nil {
+		h.logger.Warn(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	if _, err := w.Write(data); err != nil {
+		h.logger.Warn(err)
+	}
+}

internal/server/log.go

@@ -0,0 +1,75 @@
+package server
+
+import (
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/qdm12/golibs/logging"
+)
+
+func withLogMiddleware(childHandler http.Handler, logger logging.Logger, enabled bool) *logMiddleware {
+	return &logMiddleware{
+		childHandler: childHandler,
+		logger:       logger,
+		timeNow:      time.Now,
+		enabled:      enabled,
+	}
+}
+
+type logMiddleware struct {
+	childHandler http.Handler
+	logger       logging.Logger
+	timeNow      func() time.Time
+	enabled      bool
+	enabledMu    sync.RWMutex
+}
+
+func (m *logMiddleware) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if !m.isEnabled() {
+		m.childHandler.ServeHTTP(w, r)
+		return
+	}
+	tStart := m.timeNow()
+	statefulWriter := &statefulResponseWriter{httpWriter: w}
+	m.childHandler.ServeHTTP(statefulWriter, r)
+	duration := m.timeNow().Sub(tStart)
+	m.logger.Info("%d %s %s wrote %dB to %s in %s",
+		statefulWriter.statusCode, r.Method, r.RequestURI, statefulWriter.length, r.RemoteAddr, duration)
+}
+
+func (m *logMiddleware) setEnabled(enabled bool) {
+	m.enabledMu.Lock()
+	defer m.enabledMu.Unlock()
+	m.enabled = enabled
+}
+
+func (m *logMiddleware) isEnabled() (enabled bool) {
+	m.enabledMu.RLock()
+	defer m.enabledMu.RUnlock()
+	return m.enabled
+}
+
+type statefulResponseWriter struct {
+	httpWriter http.ResponseWriter
+	statusCode int
+	length     int
+}
+
+func (w *statefulResponseWriter) Write(b []byte) (n int, err error) {
+	n, err = w.httpWriter.Write(b)
+	if w.statusCode == 0 {
+		w.statusCode = http.StatusOK
+	}
+	w.length += n
+	return n, err
+}
+
+func (w *statefulResponseWriter) WriteHeader(statusCode int) {
+	w.statusCode = statusCode
+	w.httpWriter.WriteHeader(statusCode)
+}
+
+func (w *statefulResponseWriter) Header() http.Header {
+	return w.httpWriter.Header()
+}

internal/server/openvpn.go

@@ -3,34 +3,110 @@ package server
 import (
 	"encoding/json"
 	"net/http"
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/openvpn"
+	"github.com/qdm12/golibs/logging"
 )
 
-func (h *handler) getPortForwarded(w http.ResponseWriter) {
-	port := h.openvpnLooper.GetPortForwarded()
-	data, err := json.Marshal(struct {
-		Port uint16 `json:"port"`
-	}{port})
-	if err != nil {
-		h.logger.Warn(err)
-		w.WriteHeader(http.StatusInternalServerError)
-		return
-	}
-	if _, err := w.Write(data); err != nil {
-		h.logger.Warn(err)
-		w.WriteHeader(http.StatusInternalServerError)
+func newOpenvpnHandler(looper openvpn.Looper, logger logging.Logger) http.Handler {
+	return &openvpnHandler{
+		looper: looper,
+		logger: logger,
 	}
 }
 
-func (h *handler) getOpenvpnSettings(w http.ResponseWriter) {
-	settings := h.openvpnLooper.GetSettings()
-	data, err := json.Marshal(settings)
-	if err != nil {
+type openvpnHandler struct {
+	looper openvpn.Looper
+	logger logging.Logger
+}
+
+func (h *openvpnHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	r.RequestURI = strings.TrimPrefix(r.RequestURI, "/openvpn")
+	switch r.RequestURI {
+	case "/status":
+		switch r.Method {
+		case http.MethodGet:
+			h.getStatus(w)
+		case http.MethodPut:
+			h.setStatus(w, r)
+		default:
+			http.Error(w, "", http.StatusNotFound)
+		}
+	case "/settings":
+		switch r.Method {
+		case http.MethodGet:
+			h.getSettings(w)
+		default:
+			http.Error(w, "", http.StatusNotFound)
+		}
+	case "/portforwarded":
+		switch r.Method {
+		case http.MethodGet:
+			h.getPortForwarded(w)
+		default:
+			http.Error(w, "", http.StatusNotFound)
+		}
+	default:
+		http.Error(w, "", http.StatusNotFound)
+	}
+}
+
+func (h *openvpnHandler) getStatus(w http.ResponseWriter) {
+	status := h.looper.GetStatus()
+	encoder := json.NewEncoder(w)
+	data := statusWrapper{Status: string(status)}
+	if err := encoder.Encode(data); err != nil {
 		h.logger.Warn(err)
 		w.WriteHeader(http.StatusInternalServerError)
 		return
 	}
-	if _, err := w.Write(data); err != nil {
+}
+
+func (h *openvpnHandler) setStatus(w http.ResponseWriter, r *http.Request) { //nolint:dupl
+	decoder := json.NewDecoder(r.Body)
+	var data statusWrapper
+	if err := decoder.Decode(&data); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	status, err := data.getStatus()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	outcome, err := h.looper.SetStatus(status)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	encoder := json.NewEncoder(w)
+	if err := encoder.Encode(outcomeWrapper{Outcome: outcome}); err != nil {
+		h.logger.Warn(err)
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+		return
+	}
+}
+
+func (h *openvpnHandler) getSettings(w http.ResponseWriter) {
+	settings := h.looper.GetSettings()
+	settings.User = "redacted"
+	settings.Password = "redacted"
+	encoder := json.NewEncoder(w)
+	if err := encoder.Encode(settings); err != nil {
 		h.logger.Warn(err)
 		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+}
+
+func (h *openvpnHandler) getPortForwarded(w http.ResponseWriter) {
+	port := h.looper.GetPortForwarded()
+	encoder := json.NewEncoder(w)
+	data := portWrapper{Port: port}
+	if err := encoder.Encode(data); err != nil {
+		h.logger.Warn(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
 	}
 }

internal/server/server.go

@@ -23,7 +23,8 @@ type server struct {
 	handler http.Handler
 }
 
-func New(address string, logging bool, logger logging.Logger, buildInfo models.BuildInformation,
+func New(address string, logging bool, logger logging.Logger,
+	buildInfo models.BuildInformation,
 	openvpnLooper openvpn.Looper, unboundLooper dns.Looper, updaterLooper updater.Looper) Server {
 	serverLogger := logger.WithPrefix("http server: ")
 	handler := newHandler(serverLogger, logging, buildInfo, openvpnLooper, unboundLooper, updaterLooper)

internal/server/updater.go

@@ -0,0 +1,78 @@
+//nolint:dupl
+package server
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/updater"
+	"github.com/qdm12/golibs/logging"
+)
+
+func newUpdaterHandler(
+	looper updater.Looper,
+	logger logging.Logger) http.Handler {
+	return &updaterHandler{
+		looper: looper,
+		logger: logger,
+	}
+}
+
+type updaterHandler struct {
+	looper updater.Looper
+	logger logging.Logger
+}
+
+func (h *updaterHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	r.RequestURI = strings.TrimPrefix(r.RequestURI, "/updater")
+	switch r.RequestURI {
+	case "/status":
+		switch r.Method {
+		case http.MethodGet:
+			h.getStatus(w)
+		case http.MethodPut:
+			h.setStatus(w, r)
+		default:
+			http.Error(w, "", http.StatusNotFound)
+		}
+	default:
+		http.Error(w, "", http.StatusNotFound)
+	}
+}
+
+func (h *updaterHandler) getStatus(w http.ResponseWriter) {
+	status := h.looper.GetStatus()
+	encoder := json.NewEncoder(w)
+	data := statusWrapper{Status: string(status)}
+	if err := encoder.Encode(data); err != nil {
+		h.logger.Warn(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+}
+
+func (h *updaterHandler) setStatus(w http.ResponseWriter, r *http.Request) {
+	decoder := json.NewDecoder(r.Body)
+	var data statusWrapper
+	if err := decoder.Decode(&data); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	status, err := data.getStatus()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	outcome, err := h.looper.SetStatus(status)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	encoder := json.NewEncoder(w)
+	if err := encoder.Encode(outcomeWrapper{Outcome: outcome}); err != nil {
+		h.logger.Warn(err)
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+		return
+	}
+}

internal/server/version.go

@@ -1,19 +0,0 @@
-package server
-
-import (
-	"encoding/json"
-	"net/http"
-)
-
-func (h *handler) getVersion(w http.ResponseWriter) {
-	data, err := json.Marshal(h.buildInfo)
-	if err != nil {
-		h.logger.Warn(err)
-		w.WriteHeader(http.StatusInternalServerError)
-		return
-	}
-	if _, err := w.Write(data); err != nil {
-		h.logger.Warn(err)
-		w.WriteHeader(http.StatusInternalServerError)
-	}
-}

internal/server/wrappers.go

@@ -0,0 +1,32 @@
+package server
+
+import (
+	"fmt"
+
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+type statusWrapper struct {
+	Status string `json:"status"`
+}
+
+func (sw *statusWrapper) getStatus() (status models.LoopStatus, err error) {
+	status = models.LoopStatus(sw.Status)
+	switch status {
+	case constants.Stopped, constants.Running:
+		return status, nil
+	default:
+		return "", fmt.Errorf(
+			"invalid status %q: possible values are: %s, %s",
+			sw.Status, constants.Stopped, constants.Running)
+	}
+}
+
+type portWrapper struct {
+	Port uint16 `json:"port"`
+}
+
+type outcomeWrapper struct {
+	Outcome string `json:"outcome"`
+}

internal/settings/openvpn.go

@@ -12,9 +12,9 @@ import (
 // OpenVPN contains settings to configure the OpenVPN client.
 type OpenVPN struct {
 	User      string                  `json:"user"`
-	Password  string                  `json:"-"`
+	Password  string                  `json:"password"`
 	Verbosity int                     `json:"verbosity"`
-	Root      bool                    `json:"runAsRoot"`
+	Root      bool                    `json:"run_as_root"`
 	Cipher    string                  `json:"cipher"`
 	Auth      string                  `json:"auth"`
 	Provider  models.ProviderSettings `json:"provider"`

internal/settings/openvpn_test.go

@@ -20,7 +20,7 @@ func Test_OpenVPN_JSON(t *testing.T) {
 	data, err := json.Marshal(in)
 	require.NoError(t, err)
 	//nolint:lll
-	assert.Equal(t, `{"user":"","verbosity":0,"runAsRoot":true,"cipher":"","auth":"","provider":{"name":"name","serverSelection":{"networkProtocol":"","regions":null,"group":"","countries":null,"cities":null,"hostnames":null,"isps":null,"owned":false,"customPort":0,"numbers":null,"encryptionPreset":""},"extraConfig":{"encryptionPreset":"","openvpnIPv6":false},"portForwarding":{"enabled":false,"filepath":""}}}`, string(data))
+	assert.Equal(t, `{"user":"","password":"","verbosity":0,"run_as_root":true,"cipher":"","auth":"","provider":{"name":"name","server_selection":{"network_protocol":"","regions":null,"group":"","countries":null,"cities":null,"hostnames":null,"isps":null,"owned":false,"custom_port":0,"numbers":null,"encryption_preset":""},"extra_config":{"encryption_preset":"","openvpn_ipv6":false},"port_forwarding":{"enabled":false,"filepath":""}}}`, string(data))
 	var out OpenVPN
 	err = json.Unmarshal(data, &out)
 	require.NoError(t, err)

internal/settings/settings.go

@@ -1,7 +1,6 @@
 package settings
 
 import (
-	"fmt"
 	"strings"
 	"time"
 
@@ -24,7 +23,7 @@ type Settings struct {
 	HTTPProxy          HTTPProxy
 	ShadowSocks        ShadowSocks
 	PublicIPPeriod     time.Duration
-	UpdaterPeriod      time.Duration
+	Updater            Updater
 	VersionInformation bool
 	ControlServer      ControlServer
 }
@@ -34,10 +33,6 @@ func (s *Settings) String() string {
 	if s.VersionInformation {
 		versionInformation = enabled
 	}
-	updaterLine := "Updater: disabled"
-	if s.UpdaterPeriod > 0 {
-		updaterLine = fmt.Sprintf("Updater period: %s", s.UpdaterPeriod)
-	}
 	return strings.Join([]string{
 		"Settings summary below:",
 		s.OpenVPN.String(),
@@ -47,9 +42,9 @@ func (s *Settings) String() string {
 		s.HTTPProxy.String(),
 		s.ShadowSocks.String(),
 		s.ControlServer.String(),
+		s.Updater.String(),
 		"Public IP check period: " + s.PublicIPPeriod.String(), // TODO print disabled if 0
 		"Version information: " + versionInformation,
-		updaterLine,
 		"", // new line at the end
 	}, "\n")
 }
@@ -93,7 +88,7 @@ func GetAllSettings(paramsReader params.Reader) (settings Settings, err error) {
 	if err != nil {
 		return settings, err
 	}
-	settings.UpdaterPeriod, err = paramsReader.GetUpdaterPeriod()
+	settings.Updater, err = GetUpdaterSettings(paramsReader)
 	if err != nil {
 		return settings, err
 	}

internal/settings/updater.go

@@ -0,0 +1,59 @@
+package settings
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/qdm12/gluetun/internal/params"
+)
+
+type Updater struct {
+	Period     time.Duration `json:"period"`
+	DNSAddress string        `json:"dns_address"`
+	Cyberghost bool          `json:"cyberghost"`
+	Mullvad    bool          `json:"mullvad"`
+	Nordvpn    bool          `json:"nordvpn"`
+	PIA        bool          `json:"pia"`
+	Privado    bool          `json:"privado"`
+	Purevpn    bool          `json:"purevpn"`
+	Surfshark  bool          `json:"surfshark"`
+	Vyprvpn    bool          `json:"vyprvpn"`
+	Windscribe bool          `json:"windscribe"`
+	// The two below should be used in CLI mode only
+	Stdout bool `json:"-"` // in order to update constants file (maintainer side)
+	CLI    bool `json:"-"`
+}
+
+// GetUpdaterSettings obtains the server updater settings using the params functions.
+func GetUpdaterSettings(paramsReader params.Reader) (settings Updater, err error) {
+	settings = Updater{
+		Cyberghost: true,
+		Mullvad:    true,
+		Nordvpn:    true,
+		PIA:        true,
+		Purevpn:    true,
+		Surfshark:  true,
+		Vyprvpn:    true,
+		Windscribe: true,
+		Stdout:     false,
+		CLI:        false,
+		DNSAddress: "127.0.0.1",
+	}
+	settings.Period, err = paramsReader.GetUpdaterPeriod()
+	if err != nil {
+		return settings, err
+	}
+	return settings, nil
+}
+
+func (s *Updater) String() string {
+	if s.Period == 0 {
+		return "Server updater settings: disabled"
+	}
+	settingsList := []string{
+		"Server updater settings:",
+		fmt.Sprintf("Period: %s", s.Period),
+	}
+	return strings.Join(settingsList, "\n|--")
+}

internal/updater/loop.go

@@ -6,7 +6,9 @@ import (
 	"sync"
 	"time"
 
+	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/settings"
 	"github.com/qdm12/gluetun/internal/storage"
 	"github.com/qdm12/golibs/logging"
 )
@@ -14,60 +16,54 @@ import (
 type Looper interface {
 	Run(ctx context.Context, wg *sync.WaitGroup)
 	RunRestartTicker(ctx context.Context, wg *sync.WaitGroup)
-	Restart()
-	Stop()
-	GetPeriod() (period time.Duration)
-	SetPeriod(period time.Duration)
+	GetStatus() (status models.LoopStatus)
+	SetStatus(status models.LoopStatus) (outcome string, err error)
+	GetSettings() (settings settings.Updater)
+	SetSettings(settings settings.Updater) (outcome string)
 }
 
 type looper struct {
-	period        time.Duration
-	periodMutex   sync.RWMutex
+	state state
+	// Objects
 	updater       Updater
 	storage       storage.Storage
 	setAllServers func(allServers models.AllServers)
 	logger        logging.Logger
-	restart       chan struct{}
+	// Internal channels and locks
+	loopLock     sync.Mutex
+	start        chan struct{}
+	running      chan models.LoopStatus
 	stop         chan struct{}
+	stopped      chan struct{}
 	updateTicker chan struct{}
+	// Mock functions
 	timeNow   func() time.Time
 	timeSince func(time.Time) time.Duration
 }
 
-func NewLooper(options Options, period time.Duration, currentServers models.AllServers,
+func NewLooper(settings settings.Updater, currentServers models.AllServers,
 	storage storage.Storage, setAllServers func(allServers models.AllServers),
 	client *http.Client, logger logging.Logger) Looper {
 	loggerWithPrefix := logger.WithPrefix("updater: ")
 	return &looper{
-		period:        period,
-		updater:       New(options, client, currentServers, loggerWithPrefix),
+		state: state{
+			status:   constants.Stopped,
+			settings: settings,
+		},
+		updater:       New(settings, client, currentServers, loggerWithPrefix),
 		storage:       storage,
 		setAllServers: setAllServers,
 		logger:        loggerWithPrefix,
-		restart:       make(chan struct{}),
+		start:         make(chan struct{}),
+		running:       make(chan models.LoopStatus),
 		stop:          make(chan struct{}),
+		stopped:       make(chan struct{}),
 		updateTicker:  make(chan struct{}),
 		timeNow:       time.Now,
 		timeSince:     time.Since,
 	}
 }
 
-func (l *looper) Restart() { l.restart <- struct{}{} }
-func (l *looper) Stop()    { l.stop <- struct{}{} }
-
-func (l *looper) GetPeriod() (period time.Duration) {
-	l.periodMutex.RLock()
-	defer l.periodMutex.RUnlock()
-	return l.period
-}
-
-func (l *looper) SetPeriod(period time.Duration) {
-	l.periodMutex.Lock()
-	l.period = period
-	l.periodMutex.Unlock()
-	l.updateTicker <- struct{}{}
-}
-
 func (l *looper) logAndWait(ctx context.Context, err error) {
 	l.logger.Error(err)
 	const waitTime = 5 * time.Minute
@@ -84,53 +80,72 @@ func (l *looper) logAndWait(ctx context.Context, err error) {
 
 func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
 	defer wg.Done()
+	crashed := false
 	select {
-	case <-l.restart:
-		l.logger.Info("starting...")
+	case <-l.start:
 	case <-ctx.Done():
 		return
 	}
 	defer l.logger.Warn("loop exited")
 
-	enabled := true
-
 	for ctx.Err() == nil {
-		for !enabled {
-			// wait for a signal to re-enable
-			select {
-			case <-l.stop:
-				l.logger.Info("already disabled")
-			case <-l.restart:
-				enabled = true
-			case <-ctx.Done():
-				return
-			}
-		}
-
-		// Enabled and has a period set
-
-		servers, err := l.updater.UpdateServers(ctx)
+		updateCtx, updateCancel := context.WithCancel(ctx)
+		defer updateCancel()
+		serversCh := make(chan models.AllServers)
+		errorCh := make(chan error)
+		go func() {
+			servers, err := l.updater.UpdateServers(updateCtx)
 			if err != nil {
-			if ctx.Err() != nil {
+				errorCh <- err
 				return
 			}
-			l.logAndWait(ctx, err)
-			continue
+			serversCh <- servers
+		}()
+
+		if !crashed {
+			l.running <- constants.Running
+			crashed = false
+		} else {
+			l.state.setStatusWithLock(constants.Running)
 		}
+
+		stayHere := true
+		for stayHere {
+			select {
+			case <-ctx.Done():
+				l.logger.Warn("context canceled: exiting loop")
+				updateCancel()
+				close(errorCh)
+				return
+			case <-l.start:
+				l.logger.Info("starting")
+				updateCancel()
+				stayHere = false
+			case <-l.stop:
+				l.logger.Info("stopping")
+				updateCancel()
+				<-errorCh
+				l.stopped <- struct{}{}
+			case servers := <-serversCh:
+				updateCancel()
+				close(serversCh)
 				l.setAllServers(servers)
 				if err := l.storage.FlushToFile(servers); err != nil {
 					l.logger.Error(err)
 				}
+				l.state.setStatusWithLock(constants.Completed)
 				l.logger.Info("Updated servers information")
-
-		select {
-		case <-l.restart: // triggered restart
-		case <-l.stop:
-			enabled = false
-		case <-ctx.Done():
-			return
+			case err := <-errorCh:
+				updateCancel()
+				close(serversCh)
+				l.state.setStatusWithLock(constants.Crashed)
+				l.logAndWait(ctx, err)
+				crashed = true
+				stayHere = false
 			}
 		}
+		close(errorCh)
+	}
 }
 
 func (l *looper) RunRestartTicker(ctx context.Context, wg *sync.WaitGroup) {
@@ -138,7 +153,7 @@ func (l *looper) RunRestartTicker(ctx context.Context, wg *sync.WaitGroup) {
 	timer := time.NewTimer(time.Hour)
 	timer.Stop()
 	timerIsStopped := true
-	if period := l.GetPeriod(); period > 0 {
+	if period := l.GetSettings().Period; period > 0 {
 		timerIsStopped = false
 		timer.Reset(period)
 	}
@@ -152,14 +167,14 @@ func (l *looper) RunRestartTicker(ctx context.Context, wg *sync.WaitGroup) {
 			return
 		case <-timer.C:
 			lastTick = l.timeNow()
-			l.restart <- struct{}{}
-			timer.Reset(l.GetPeriod())
+			l.start <- struct{}{}
+			timer.Reset(l.GetSettings().Period)
 		case <-l.updateTicker:
 			if !timerIsStopped && !timer.Stop() {
 				<-timer.C
 			}
 			timerIsStopped = true
-			period := l.GetPeriod()
+			period := l.GetSettings().Period
 			if period == 0 {
 				continue
 			}

internal/updater/options.go

@@ -1,32 +0,0 @@
-package updater
-
-type Options struct {
-	Cyberghost bool
-	Mullvad    bool
-	Nordvpn    bool
-	PIA        bool
-	Privado    bool
-	Purevpn    bool
-	Surfshark  bool
-	Vyprvpn    bool
-	Windscribe bool
-	Stdout     bool // in order to update constants file (maintainer side)
-	CLI        bool
-	DNSAddress string
-}
-
-func NewOptions(dnsAddress string) Options {
-	return Options{
-		Cyberghost: true,
-		Mullvad:    true,
-		Nordvpn:    true,
-		PIA:        true,
-		Purevpn:    true,
-		Surfshark:  true,
-		Vyprvpn:    true,
-		Windscribe: true,
-		Stdout:     false,
-		CLI:        false,
-		DNSAddress: dnsAddress,
-	}
-}

internal/updater/state.go

@@ -0,0 +1,88 @@
+package updater
+
+import (
+	"fmt"
+	"reflect"
+	"sync"
+
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/settings"
+)
+
+type state struct {
+	status   models.LoopStatus
+	settings settings.Updater
+	statusMu sync.RWMutex
+	periodMu sync.RWMutex
+}
+
+func (s *state) setStatusWithLock(status models.LoopStatus) {
+	s.statusMu.Lock()
+	defer s.statusMu.Unlock()
+	s.status = status
+}
+
+func (l *looper) GetStatus() (status models.LoopStatus) {
+	l.state.statusMu.RLock()
+	defer l.state.statusMu.RUnlock()
+	return l.state.status
+}
+
+func (l *looper) SetStatus(status models.LoopStatus) (outcome string, err error) {
+	l.state.statusMu.Lock()
+	defer l.state.statusMu.Unlock()
+	existingStatus := l.state.status
+
+	switch status {
+	case constants.Running:
+		switch existingStatus {
+		case constants.Starting, constants.Running, constants.Stopping, constants.Crashed:
+			return fmt.Sprintf("already %s", existingStatus), nil
+		}
+		l.loopLock.Lock()
+		defer l.loopLock.Unlock()
+		l.state.status = constants.Starting
+		l.state.statusMu.Unlock()
+		l.start <- struct{}{}
+		newStatus := <-l.running
+		l.state.statusMu.Lock()
+		l.state.status = newStatus
+		return newStatus.String(), nil
+	case constants.Stopped:
+		switch existingStatus {
+		case constants.Stopped, constants.Stopping, constants.Starting, constants.Crashed:
+			return fmt.Sprintf("already %s", existingStatus), nil
+		}
+		l.loopLock.Lock()
+		defer l.loopLock.Unlock()
+		l.state.status = constants.Stopping
+		l.state.statusMu.Unlock()
+		l.stop <- struct{}{}
+		<-l.stopped
+		l.state.statusMu.Lock()
+		l.state.status = status
+		return status.String(), nil
+	default:
+		return "", fmt.Errorf("status %q can only be %q or %q",
+			status, constants.Running, constants.Stopped)
+	}
+}
+
+func (l *looper) GetSettings() (settings settings.Updater) {
+	l.state.periodMu.RLock()
+	defer l.state.periodMu.RUnlock()
+	return l.state.settings
+}
+
+func (l *looper) SetSettings(settings settings.Updater) (outcome string) {
+	l.state.periodMu.Lock()
+	defer l.state.periodMu.Unlock()
+	settingsUnchanged := reflect.DeepEqual(settings, l.state.settings)
+	if settingsUnchanged {
+		return "settings left unchanged"
+	}
+	l.state.settings = settings
+	l.updateTicker <- struct{}{}
+	return "settings updated"
+}

internal/updater/updater.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/settings"
 	"github.com/qdm12/golibs/logging"
 	"github.com/qdm12/golibs/network"
 )
@@ -17,7 +18,7 @@ type Updater interface {
 
 type updater struct {
 	// configuration
-	options Options
+	options settings.Updater
 
 	// state
 	servers models.AllServers
@@ -30,11 +31,12 @@ type updater struct {
 	client   network.Client
 }
 
-func New(options Options, httpClient *http.Client, currentServers models.AllServers, logger logging.Logger) Updater {
-	if len(options.DNSAddress) == 0 {
-		options.DNSAddress = "1.1.1.1"
+func New(settings settings.Updater, httpClient *http.Client,
+	currentServers models.AllServers, logger logging.Logger) Updater {
+	if len(settings.DNSAddress) == 0 {
+		settings.DNSAddress = "1.1.1.1"
 	}
-	resolver := newResolver(options.DNSAddress)
+	resolver := newResolver(settings.DNSAddress)
 	const clientTimeout = 10 * time.Second
 	return &updater{
 		logger:   logger,
@@ -42,7 +44,7 @@ func New(options Options, httpClient *http.Client, currentServers models.AllServ
 		println:  func(s string) { fmt.Println(s) },
 		lookupIP: newLookupIP(resolver),
 		client:   network.NewClient(clientTimeout),
-		options:  options,
+		options:  settings,
 		servers:  currentServers,
 	}
 }