feat: add pre-hook and post-hook in restore command

subcommands/restore/plakar-restore.1

@@ -11,6 +11,8 @@
 .Op Fl job Ar job
 .Op Fl name Ar name
 .Op Fl perimeter Ar perimeter
+.Op Fl post-hook Ar command
+.Op Fl pre-hook Ar command
 .Op Fl skip-permissions
 .Op Fl tag Ar tag
 .Op Fl to Ar directory
@@ -52,6 +54,17 @@ Only apply command to snapshots that match
 .It Fl tag Ar string
 Only apply command to snapshots that match
 .Ar tag .
+.It Fl pre-hook Ar command
+Run
+.Ar command
+in a shell before starting the restore.
+If the command exits with a non-zero status, restore is aborted.
+.It Fl post-hook Ar command
+Run
+.Ar command
+in a shell after a successful restore.
+If the command exits with a non-zero status, a warning is logged and
+the restore still succeeds.
 .It Fl skip-permissions
 Skip restoring file permissions and ownership during restore,
 defaulting to 0750 for directories and 0640 for files.

subcommands/restore/restore.go

@@ -20,7 +20,9 @@ import (
 	"flag"
 	"fmt"
 	"maps"
+	"os/exec"
 	"path"
+	"runtime"
 	"strings"
 	"time"
 
@@ -44,6 +46,8 @@ type Restore struct {
 	OptTag             string
 	OptSkipPermissions bool
 	Opts               map[string]string
+	OptPreHook         string
+	OptPostHook        string
 
 	Target    string
 	Strip     string
@@ -76,6 +80,8 @@ func (cmd *Restore) Parse(ctx *appcontext.AppContext, args []string) error {
 
 	flags.StringVar(&pullPath, "to", "", "base directory where pull will restore")
 	flags.BoolVar(&cmd.OptSkipPermissions, "skip-permissions", false, "do not restore file permissions")
+	flags.StringVar(&cmd.OptPreHook, "pre-hook", "", "shell command to run before restore")
+	flags.StringVar(&cmd.OptPostHook, "post-hook", "", "shell command to run after restore")
 	flags.Parse(args)
 
 	if flags.NArg() != 0 {
@@ -147,6 +153,10 @@ func (cmd *Restore) Execute(ctx *appcontext.AppContext, repo *repository.Reposit
 		return 1, fmt.Errorf("multiple snapshots found, please specify one")
 	}
 
+	if err := executeHook(ctx, cmd.OptPreHook); err != nil {
+		return 1, fmt.Errorf("pre-restore hook failed: %w", err)
+	}
+
 	exporterConfig := map[string]string{
 		"location": cmd.Target,
 	}
@@ -200,5 +210,29 @@ func (cmd *Restore) Execute(ctx *appcontext.AppContext, repo *repository.Reposit
 
 		snap.Close()
 	}
+
+	if err := executeHook(ctx, cmd.OptPostHook); err != nil {
+		ctx.GetLogger().Warn("post-restore hook failed: %s", err)
+	}
+
 	return 0, nil
 }
+
+func executeHook(ctx *appcontext.AppContext, hook string) error {
+	if hook == "" {
+		return nil
+	}
+	ctx.GetLogger().Info("executing hook: %s", hook)
+
+	var cmd *exec.Cmd
+	switch runtime.GOOS {
+	case "windows":
+		cmd = exec.Command("cmd", "/C", hook)
+	default: // assume unix-esque
+		cmd = exec.Command("/bin/sh", "-c", hook)
+	}
+
+	cmd.Stdout = ctx.Stdout
+	cmd.Stderr = ctx.Stderr
+	return cmd.Run()
+}

subcommands/restore/restore_extra_test.go

@@ -1,6 +1,7 @@
 package restore
 
 import (
+	"bytes"
 	"encoding/hex"
 	"fmt"
 	"os"
@@ -152,6 +153,96 @@ func TestRestoreExporterOptsParsed(t *testing.T) {
 	require.Equal(t, "y", cmd.Opts["x"])
 }
 
+func TestRestoreHooksFlagsAreParsed(t *testing.T) {
+	_, _, ctx := generateSnapshot(t)
+	cmd := &Restore{}
+	require.NoError(t, cmd.Parse(ctx, []string{
+		"-pre-hook", "echo 'pre-restore hook'",
+		"-post-hook", "echo 'post-restore hook'",
+		"-to", "/tmp/x",
+	}))
+	require.Equal(t, "echo 'pre-restore hook'", cmd.OptPreHook)
+	require.Equal(t, "echo 'post-restore hook'", cmd.OptPostHook)
+}
+
+func TestRestoreWithHooks(t *testing.T) {
+	repo, snap, ctx := generateSnapshot(t)
+	defer snap.Close()
+
+	dir := mkRestoreDir(t)
+	bufOut := bytes.NewBuffer(nil)
+	bufErr := bytes.NewBuffer(nil)
+	ctx.Stdout = bufOut
+	ctx.Stderr = bufErr
+
+	id := snap.Header.GetIndexID()
+	cmd := &Restore{}
+	require.NoError(t, cmd.Parse(ctx, []string{
+		"-to", dir,
+		"-pre-hook", "echo 'pre-restore hook executed'",
+		"-post-hook", "echo 'post-restore hook executed'",
+		hex.EncodeToString(id[:]) + ":",
+	}))
+
+	status, err := cmd.Execute(ctx, repo)
+	require.NoError(t, err)
+	require.Equal(t, 0, status)
+
+	output := bufOut.String()
+	require.Contains(t, output, "pre-restore hook executed")
+	require.Contains(t, output, "post-restore hook executed")
+
+	checkRestored(t, dir)
+}
+
+func TestRestorePreHookFailureAbortsRestore(t *testing.T) {
+	repo, snap, ctx := generateSnapshot(t)
+	defer snap.Close()
+
+	dir := mkRestoreDir(t)
+	id := snap.Header.GetIndexID()
+	cmd := &Restore{}
+	require.NoError(t, cmd.Parse(ctx, []string{
+		"-to", dir,
+		"-pre-hook", "exit 7",
+		hex.EncodeToString(id[:]) + ":",
+	}))
+
+	status, err := cmd.Execute(ctx, repo)
+	require.Error(t, err)
+	require.Equal(t, 1, status)
+	require.Contains(t, err.Error(), "pre-restore hook failed")
+
+	rest, readErr := os.ReadDir(dir)
+	require.NoError(t, readErr)
+	require.Empty(t, rest)
+}
+
+func TestRestorePostHookFailureIsNotFatal(t *testing.T) {
+	repo, snap, ctx := generateSnapshot(t)
+	defer snap.Close()
+
+	dir := mkRestoreDir(t)
+	bufOut := bytes.NewBuffer(nil)
+	bufErr := bytes.NewBuffer(nil)
+	ctx.Stdout = bufOut
+	ctx.Stderr = bufErr
+
+	id := snap.Header.GetIndexID()
+	cmd := &Restore{}
+	require.NoError(t, cmd.Parse(ctx, []string{
+		"-to", dir,
+		"-post-hook", "exit 9",
+		hex.EncodeToString(id[:]) + ":",
+	}))
+
+	status, err := cmd.Execute(ctx, repo)
+	require.NoError(t, err)
+	require.Equal(t, 0, status)
+
+	checkRestored(t, dir)
+}
+
 func TestRestoreInvalidSnapshotID(t *testing.T) {
 	// A garbage snapshot ID should yield "no snapshots found" (because it
 	// matches nothing in the locate filter).