Code maintenance: Unix abstraction interface

- Used for creating the tun device if it does not exist
- Mocks generated for testing

.golangci.yml

@@ -14,7 +14,10 @@ issues:
       linters:
         - gochecknoglobals
       text: IsNotExist is a global variable
-
+    - path: internal/unix/constants\.go
+      linters:
+        - golint
+      text: don't use ALL_CAPS in Go names; use CamelCase
 linters:
   disable-all: true
   enable:

cmd/gluetun/main.go

@@ -30,6 +30,7 @@ import (
 	"github.com/qdm12/gluetun/internal/settings"
 	"github.com/qdm12/gluetun/internal/shadowsocks"
 	"github.com/qdm12/gluetun/internal/storage"
+	"github.com/qdm12/gluetun/internal/unix"
 	"github.com/qdm12/gluetun/internal/updater"
 	versionpkg "github.com/qdm12/gluetun/internal/version"
 	"github.com/qdm12/golibs/command"
@@ -86,7 +87,8 @@ func _main(background context.Context, args []string, os os.OS) int {
 	client := network.NewClient(clientTimeout)
 	// Create configurators
 	alpineConf := alpine.NewConfigurator(os.OpenFile)
-	ovpnConf := openvpn.NewConfigurator(logger, os)
+	unix := unix.New()
+	ovpnConf := openvpn.NewConfigurator(logger, os, unix)
 	dnsConf := dns.NewConfigurator(logger, client, os.OpenFile)
 	routingConf := routing.NewRouting(logger)
 	firewallConf := firewall.NewConfigurator(logger, routingConf, os.OpenFile)

internal/openvpn/openvpn.go

@@ -5,9 +5,9 @@ import (
 	"io"
 
 	"github.com/qdm12/gluetun/internal/os"
+	"github.com/qdm12/gluetun/internal/unix"
 	"github.com/qdm12/golibs/command"
 	"github.com/qdm12/golibs/logging"
-	"golang.org/x/sys/unix"
 )
 
 type Configurator interface {
@@ -22,16 +22,14 @@ type configurator struct {
 	logger    logging.Logger
 	commander command.Commander
 	os        os.OS
-	mkDev     func(major uint32, minor uint32) uint64
-	mkNod     func(path string, mode uint32, dev int) error
+	unix      unix.Unix
 }
 
-func NewConfigurator(logger logging.Logger, os os.OS) Configurator {
+func NewConfigurator(logger logging.Logger, os os.OS, unix unix.Unix) Configurator {
 	return &configurator{
 		logger:    logger.WithPrefix("openvpn configurator: "),
 		commander: command.NewCommander(),
 		os:        os,
-		mkDev:     unix.Mkdev,
-		mkNod:     unix.Mknod,
+		unix:      unix,
 	}
 }

internal/openvpn/tun.go

@@ -5,7 +5,7 @@ import (
 	"os"
 
 	"github.com/qdm12/gluetun/internal/constants"
-	"golang.org/x/sys/unix"
+	"github.com/qdm12/gluetun/internal/unix"
 )
 
 // CheckTUN checks the tunnel device is present and accessible.
@@ -31,8 +31,8 @@ func (c *configurator) CreateTUN() error {
 		major = 10
 		minor = 200
 	)
-	dev := c.mkDev(major, minor)
-	if err := c.mkNod(string(constants.TunnelDevice), unix.S_IFCHR, int(dev)); err != nil {
+	dev := c.unix.Mkdev(major, minor)
+	if err := c.unix.Mknod(string(constants.TunnelDevice), unix.S_IFCHR, int(dev)); err != nil {
 		return err
 	}
 

internal/unix/constants.go

@@ -0,0 +1,9 @@
+package unix
+
+import sysunix "golang.org/x/sys/unix"
+
+// Constants used for convenience so "os" does not have to be imported
+
+const (
+	S_IFCHR = sysunix.S_IFCHR
+)

internal/unix/mock_unix/unix.go

@@ -0,0 +1,61 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/qdm12/gluetun/internal/unix (interfaces: Unix)
+
+// Package mock_unix is a generated GoMock package.
+package mock_unix
+
+import (
+	gomock "github.com/golang/mock/gomock"
+	reflect "reflect"
+)
+
+// MockUnix is a mock of Unix interface
+type MockUnix struct {
+	ctrl     *gomock.Controller
+	recorder *MockUnixMockRecorder
+}
+
+// MockUnixMockRecorder is the mock recorder for MockUnix
+type MockUnixMockRecorder struct {
+	mock *MockUnix
+}
+
+// NewMockUnix creates a new mock instance
+func NewMockUnix(ctrl *gomock.Controller) *MockUnix {
+	mock := &MockUnix{ctrl: ctrl}
+	mock.recorder = &MockUnixMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockUnix) EXPECT() *MockUnixMockRecorder {
+	return m.recorder
+}
+
+// Mkdev mocks base method
+func (m *MockUnix) Mkdev(arg0, arg1 uint32) uint64 {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Mkdev", arg0, arg1)
+	ret0, _ := ret[0].(uint64)
+	return ret0
+}
+
+// Mkdev indicates an expected call of Mkdev
+func (mr *MockUnixMockRecorder) Mkdev(arg0, arg1 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Mkdev", reflect.TypeOf((*MockUnix)(nil).Mkdev), arg0, arg1)
+}
+
+// Mknod mocks base method
+func (m *MockUnix) Mknod(arg0 string, arg1 uint32, arg2 int) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Mknod", arg0, arg1, arg2)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Mknod indicates an expected call of Mknod
+func (mr *MockUnixMockRecorder) Mknod(arg0, arg1, arg2 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Mknod", reflect.TypeOf((*MockUnix)(nil).Mknod), arg0, arg1, arg2)
+}

internal/unix/unix.go

@@ -0,0 +1,24 @@
+package unix
+
+import sysunix "golang.org/x/sys/unix"
+
+//go:generate mockgen -destination=mock_$GOPACKAGE/$GOFILE . Unix
+
+type Unix interface {
+	Mkdev(major uint32, minor uint32) uint64
+	Mknod(path string, mode uint32, dev int) (err error)
+}
+
+func New() Unix {
+	return &unix{}
+}
+
+type unix struct{}
+
+func (u *unix) Mkdev(major uint32, minor uint32) uint64 {
+	return sysunix.Mkdev(major, minor)
+}
+
+func (u *unix) Mknod(path string, mode uint32, dev int) (err error) {
+	return sysunix.Mknod(path, mode, dev)
+}