move implementation to internal/ directory (#828)

internal/client/stdinserver.go

@@ -0,0 +1,51 @@
+package client
+
+import (
+	"os"
+
+	"github.com/problame/go-netssh"
+
+	"github.com/zrepl/zrepl/internal/cli"
+	"github.com/zrepl/zrepl/internal/config"
+
+	"context"
+	"errors"
+	"log"
+	"path"
+)
+
+var StdinserverCmd = &cli.Subcommand{
+	Use:   "stdinserver CLIENT_IDENTITY",
+	Short: "stdinserver transport mode (started from authorized_keys file as forced command)",
+	Run: func(ctx context.Context, subcommand *cli.Subcommand, args []string) error {
+		return runStdinserver(subcommand.Config(), args)
+	},
+}
+
+func runStdinserver(config *config.Config, args []string) error {
+
+	// NOTE: the netssh proxying protocol requires exiting with non-zero status if anything goes wrong
+	defer os.Exit(1)
+
+	log := log.New(os.Stderr, "", log.LUTC|log.Ldate|log.Ltime)
+
+	if len(args) != 1 || args[0] == "" {
+		err := errors.New("must specify client_identity as positional argument")
+		return err
+	}
+
+	identity := args[0]
+	unixaddr := path.Join(config.Global.Serve.StdinServer.SockDir, identity)
+
+	log.Printf("proxying client identity '%s' to zrepl daemon '%s'", identity, unixaddr)
+
+	ctx := netssh.ContextWithLog(context.TODO(), log)
+
+	err := netssh.Proxy(ctx, unixaddr)
+	if err == nil {
+		log.Print("proxying finished successfully, exiting with status 0")
+		os.Exit(0)
+	}
+	log.Printf("error proxying: %s", err)
+	return nil
+}