Merge pull request #350 from restic/allow-read-only-ops

Allow check/restore read-only, without locking

cmd/restic/cmd_check.go

@@ -9,8 +9,8 @@ import (
 )
 
 type CmdCheck struct {
-	ReadData    bool `long:"read-data"   description:"Read data blobs" default:"false"`
-	CheckUnused bool `long:"check-unused" description:"Check for unused blobs" default:"false"`
+	ReadData    bool `long:"read-data"    default:"false" description:"Read data blobs"`
+	CheckUnused bool `long:"check-unused" default:"false" description:"Check for unused blobs"`
 
 	global *GlobalOptions
 }
@@ -39,11 +39,13 @@ func (cmd CmdCheck) Execute(args []string) error {
 		return err
 	}
 
-	cmd.global.Verbosef("Create exclusive lock for repository\n")
-	lock, err := lockRepoExclusive(repo)
-	defer unlockRepo(lock)
-	if err != nil {
-		return err
+	if !cmd.global.NoLock {
+		cmd.global.Verbosef("Create exclusive lock for repository\n")
+		lock, err := lockRepoExclusive(repo)
+		defer unlockRepo(lock)
+		if err != nil {
+			return err
+		}
 	}
 
 	chkr := checker.New(repo)

cmd/restic/cmd_list.go

@@ -35,10 +35,12 @@ func (cmd CmdList) Execute(args []string) error {
 		return err
 	}
 
-	lock, err := lockRepo(repo)
-	defer unlockRepo(lock)
-	if err != nil {
-		return err
+	if !cmd.global.NoLock {
+		lock, err := lockRepo(repo)
+		defer unlockRepo(lock)
+		if err != nil {
+			return err
+		}
 	}
 
 	var t backend.Type

cmd/restic/cmd_restore.go

@@ -53,10 +53,12 @@ func (cmd CmdRestore) Execute(args []string) error {
 		return err
 	}
 
-	lock, err := lockRepo(repo)
-	defer unlockRepo(lock)
-	if err != nil {
-		return err
+	if !cmd.global.NoLock {
+		lock, err := lockRepo(repo)
+		defer unlockRepo(lock)
+		if err != nil {
+			return err
+		}
 	}
 
 	err = repo.LoadIndex()

cmd/restic/global.go

@@ -24,6 +24,7 @@ type GlobalOptions struct {
 	Repo     string `short:"r" long:"repo"                      description:"Repository directory to backup to/restore from"`
 	CacheDir string `          long:"cache-dir"                 description:"Directory to use as a local cache"`
 	Quiet    bool   `short:"q" long:"quiet"     default:"false" description:"Do not output comprehensive progress report"`
+	NoLock   bool   `          long:"no-lock"   default:"false" description:"Do not lock the repo, this allows some operations on read-only repos."`
 
 	password string
 	stdout   io.Writer

cmd/restic/integration_test.go

@@ -62,14 +62,15 @@ func cmdBackupExcludes(t testing.TB, global GlobalOptions, target []string, pare
 }
 
 func cmdList(t testing.TB, global GlobalOptions, tpe string) backend.IDs {
-	var buf bytes.Buffer
-	global.stdout = &buf
 	cmd := &CmdList{global: &global}
+	return executeAndParseIDs(t, cmd, tpe)
+}
 
-	OK(t, cmd.Execute([]string{tpe}))
-	IDs := parseIDsFromReader(t, &buf)
-
-	return IDs
+func executeAndParseIDs(t testing.TB, cmd *CmdList, args ...string) backend.IDs {
+	buf := bytes.NewBuffer(nil)
+	cmd.global.stdout = buf
+	OK(t, cmd.Execute(args))
+	return parseIDsFromReader(t, buf)
 }
 
 func cmdRestore(t testing.TB, global GlobalOptions, dir string, snapshotID backend.ID) {
@@ -788,3 +789,28 @@ func TestOptimizeRemoveUnusedBlobs(t *testing.T) {
 		})
 	}
 }
+
+func TestCheckRestoreNoLock(t *testing.T) {
+	withTestEnvironment(t, func(env *testEnvironment, global GlobalOptions) {
+		datafile := filepath.Join("testdata", "small-repo.tar.gz")
+		SetupTarTestFixture(t, env.base, datafile)
+
+		err := filepath.Walk(env.repo, func(p string, fi os.FileInfo, e error) error {
+			if e != nil {
+				return e
+			}
+			return os.Chmod(p, fi.Mode() & ^(os.FileMode(0222)))
+		})
+		OK(t, err)
+
+		global.NoLock = true
+		cmdCheck(t, global)
+
+		snapshotIDs := cmdList(t, global, "snapshots")
+		if len(snapshotIDs) == 0 {
+			t.Fatalf("found no snapshots")
+		}
+
+		cmdRestore(t, global, filepath.Join(env.base, "restore"), snapshotIDs[0])
+	})
+}