feat(devrun): add initial implementation of devrun tool

See ./devrun/README.md for more details.

devrun/cmd/main.go

@@ -0,0 +1,156 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+
+	"github.com/qdm12/gluetun/devrun/internal"
+)
+
+func main() {
+	const minArgs = 2
+	if len(os.Args) < minArgs {
+		printUsage()
+		os.Exit(1)
+	}
+
+	switch os.Args[1] {
+	case "add-cred":
+		const addCredMinArgs = 4
+		if len(os.Args) < addCredMinArgs {
+			fmt.Fprintf(os.Stderr,
+				`Usage: %s add-cred <provider> <vpn-type>
+Example: %s add-cred protonvpn wireguard`, os.Args[0], os.Args[0])
+			os.Exit(1)
+		}
+		provider := os.Args[2]
+		vpnType := os.Args[3]
+		err := runWithSignals(func(ctx context.Context, _ <-chan struct{}) error {
+			return internal.AddCredential(ctx, provider, vpnType)
+		})
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "add-cred failed:", err)
+			os.Exit(1)
+		}
+	case "delete-cred":
+		const deleteCredMinArgs = 4
+		if len(os.Args) < deleteCredMinArgs {
+			fmt.Fprintf(os.Stderr,
+				`Usage: %s delete-cred <provider> <vpn-type>
+Example: %s delete-cred protonvpn openvpn`, os.Args[0], os.Args[0])
+			os.Exit(1)
+		}
+		provider := os.Args[2]
+		vpnType := os.Args[3]
+		err := runWithSignals(func(ctx context.Context, _ <-chan struct{}) error {
+			return internal.DeleteCredential(ctx, provider, vpnType)
+		})
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "delete-cred failed:", err)
+			os.Exit(1)
+		}
+	case "dump-cred":
+		const dumpCredMinArgs = 4
+		if len(os.Args) < dumpCredMinArgs {
+			fmt.Fprintf(os.Stderr,
+				`Usage: %s dump-cred <provider> <vpn-type>
+Example: %s dump-cred protonvpn wireguard`, os.Args[0], os.Args[0])
+			os.Exit(1)
+		}
+		provider := os.Args[2]
+		vpnType := os.Args[3]
+		err := runWithSignals(func(ctx context.Context, _ <-chan struct{}) error {
+			return internal.DumpCredential(ctx, provider, vpnType)
+		})
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "dump-cred failed:", err)
+			os.Exit(1)
+		}
+	case "run":
+		const runMinArgs = 4
+		if len(os.Args) < runMinArgs {
+			fmt.Fprintf(os.Stderr,
+				`Usage: %s run <provider> <vpn-type> [extra docker flags...]
+Example: %s run mullvad wireguard -e SERVER_COUNTRIES=USA`, os.Args[0], os.Args[0])
+			os.Exit(1)
+		}
+		provider := os.Args[2]
+		vpnType := os.Args[3]
+		extraArgs := os.Args[4:]
+		err := runWithSignals(func(ctx context.Context, forceKill <-chan struct{}) error {
+			return internal.Run(ctx, provider, vpnType, extraArgs, forceKill)
+		})
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "run failed:", err)
+			os.Exit(1)
+		}
+	default:
+		fmt.Fprintln(os.Stderr, "unknown command:", os.Args[1])
+		printUsage()
+		os.Exit(1)
+	}
+}
+
+func printUsage() {
+	fmt.Fprintf(os.Stderr, `Usage: %s <command> [args...]
+
+Commands:
+	add-cred <provider> <vpn-type>
+				Add or replace credentials in the encrypted credentials store.
+	delete-cred <provider> <vpn-type>
+				Delete credentials from the encrypted credentials store.
+	dump-cred <provider> <vpn-type>
+				Print credentials for a provider and VPN type pair.
+	run <provider> <vpn-type> [flags...]
+				Decrypt credentials and run a Gluetun container.
+				Extra flags (e.g. -e PORT_FORWARDING=on) are passed to docker run.`,
+		os.Args[0])
+}
+
+func runWithSignals(runFn func(ctx context.Context, forceKill <-chan struct{}) error) error {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	const signalBufferSize = 3
+	sigCh := make(chan os.Signal, signalBufferSize)
+	signal.Notify(sigCh, os.Interrupt)
+	defer signal.Stop(sigCh)
+
+	forceKill := make(chan struct{})
+	stopSignalLoop := make(chan struct{})
+	signalLoopDone := make(chan struct{})
+
+	go func() {
+		defer close(signalLoopDone)
+
+		const secondInterrupt = 2
+		interruptCount := uint(0)
+		forceKillSent := false
+		for {
+			select {
+			case <-stopSignalLoop:
+				return
+			case <-sigCh:
+				interruptCount++
+				switch interruptCount {
+				case 1:
+					cancel()
+				case secondInterrupt:
+					if !forceKillSent {
+						close(forceKill)
+						forceKillSent = true
+					}
+				default:
+					os.Exit(1)
+				}
+			}
+		}
+	}()
+
+	err := runFn(ctx, forceKill)
+	close(stopSignalLoop)
+	<-signalLoopDone
+	return err
+}