Maint: move OpenVPN configurator to openvpn/config

internal/openvpn/config/auth.go

@@ -0,0 +1,69 @@
+package config
+
+import (
+	"io"
+	"os"
+	"strings"
+)
+
+type AuthWriter interface {
+	WriteAuthFile(user, password string) error
+}
+
+// WriteAuthFile writes the OpenVPN auth file to disk with the right permissions.
+func (c *configurator) WriteAuthFile(user, password string) error {
+	file, err := os.Open(c.authFilePath)
+
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+
+	if os.IsNotExist(err) {
+		file, err = os.OpenFile(c.authFilePath, os.O_WRONLY|os.O_CREATE, 0400)
+		if err != nil {
+			return err
+		}
+		_, err = file.WriteString(user + "\n" + password)
+		if err != nil {
+			_ = file.Close()
+			return err
+		}
+		err = file.Chown(c.puid, c.pgid)
+		if err != nil {
+			_ = file.Close()
+			return err
+		}
+		return file.Close()
+	}
+
+	data, err := io.ReadAll(file)
+	if err != nil {
+		_ = file.Close()
+		return err
+	}
+	if err := file.Close(); err != nil {
+		return err
+	}
+
+	lines := strings.Split(string(data), "\n")
+	if len(lines) > 1 && lines[0] == user && lines[1] == password {
+		return nil
+	}
+
+	c.logger.Info("username and password changed in " + c.authFilePath)
+	file, err = os.OpenFile(c.authFilePath, os.O_TRUNC|os.O_WRONLY, 0400)
+	if err != nil {
+		return err
+	}
+	_, err = file.WriteString(user + "\n" + password)
+	if err != nil {
+		_ = file.Close()
+		return err
+	}
+	err = file.Chown(c.puid, c.pgid)
+	if err != nil {
+		_ = file.Close()
+		return err
+	}
+	return file.Close()
+}

internal/openvpn/config/command.go

@@ -0,0 +1,76 @@
+package config
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+	"syscall"
+
+	"github.com/qdm12/gluetun/internal/constants"
+)
+
+var ErrVersionUnknown = errors.New("OpenVPN version is unknown")
+
+const (
+	binOpenvpn24 = "openvpn2.4"
+	binOpenvpn25 = "openvpn"
+)
+
+type Starter interface {
+	Start(ctx context.Context, version string, flags []string) (
+		stdoutLines, stderrLines chan string, waitError chan error, err error)
+}
+
+func (c *configurator) Start(ctx context.Context, version string, flags []string) (
+	stdoutLines, stderrLines chan string, waitError chan error, err error) {
+	var bin string
+	switch version {
+	case constants.Openvpn24:
+		bin = binOpenvpn24
+	case constants.Openvpn25:
+		bin = binOpenvpn25
+	default:
+		return nil, nil, nil, fmt.Errorf("%w: %s", ErrVersionUnknown, version)
+	}
+
+	c.logger.Info("starting OpenVPN " + version)
+
+	args := []string{"--config", constants.OpenVPNConf}
+	args = append(args, flags...)
+	cmd := exec.CommandContext(ctx, bin, args...)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+
+	return c.cmder.Start(cmd)
+}
+
+type VersionGetter interface {
+	Version24(ctx context.Context) (version string, err error)
+	Version25(ctx context.Context) (version string, err error)
+}
+
+func (c *configurator) Version24(ctx context.Context) (version string, err error) {
+	return c.version(ctx, binOpenvpn24)
+}
+
+func (c *configurator) Version25(ctx context.Context) (version string, err error) {
+	return c.version(ctx, binOpenvpn25)
+}
+
+var ErrVersionTooShort = errors.New("version output is too short")
+
+func (c *configurator) version(ctx context.Context, binName string) (version string, err error) {
+	cmd := exec.CommandContext(ctx, binName, "--version")
+	output, err := c.cmder.Run(cmd)
+	if err != nil && err.Error() != "exit status 1" {
+		return "", err
+	}
+	firstLine := strings.Split(output, "\n")[0]
+	words := strings.Fields(firstLine)
+	const minWords = 2
+	if len(words) < minWords {
+		return "", fmt.Errorf("%w: %s", ErrVersionTooShort, firstLine)
+	}
+	return words[1], nil
+}

internal/openvpn/config/config.go

@@ -0,0 +1,30 @@
+package config
+
+import (
+	"os"
+	"strings"
+)
+
+type Writer interface {
+	WriteConfig(lines []string) error
+}
+
+func (c *configurator) WriteConfig(lines []string) error {
+	file, err := os.OpenFile(c.configPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
+	if err != nil {
+		return err
+	}
+	_, err = file.WriteString(strings.Join(lines, "\n"))
+	if err != nil {
+		_ = file.Close()
+		return err
+	}
+
+	err = file.Chown(c.puid, c.pgid)
+	if err != nil {
+		_ = file.Close()
+		return err
+	}
+
+	return file.Close()
+}

internal/openvpn/config/openvpn.go

@@ -0,0 +1,34 @@
+package config
+
+import (
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/golibs/command"
+	"github.com/qdm12/golibs/logging"
+)
+
+type Configurator interface {
+	VersionGetter
+	AuthWriter
+	Starter
+	Writer
+}
+
+type configurator struct {
+	logger       logging.Logger
+	cmder        command.RunStarter
+	configPath   string
+	authFilePath string
+	puid, pgid   int
+}
+
+func NewConfigurator(logger logging.Logger,
+	cmder command.RunStarter, puid, pgid int) Configurator {
+	return &configurator{
+		logger:       logger,
+		cmder:        cmder,
+		configPath:   constants.OpenVPNConf,
+		authFilePath: constants.OpenVPNAuthConf,
+		puid:         puid,
+		pgid:         pgid,
+	}
+}