Add support for checkpoint/restore of containers with volumes

cmd/podman/containers/checkpoint.go

@@ -57,6 +57,7 @@ func init() {
 	_ = checkpointCommand.RegisterFlagCompletionFunc(exportFlagName, completion.AutocompleteDefault)
 
 	flags.BoolVar(&checkpointOptions.IgnoreRootFS, "ignore-rootfs", false, "Do not include root file-system changes when exporting")
+	flags.BoolVar(&checkpointOptions.IgnoreVolumes, "ignore-volumes", false, "Do not export volumes associated with container")
 	validate.AddLatestFlag(checkpointCommand, &checkpointOptions.Latest)
 }
 
@@ -68,6 +69,9 @@ func checkpoint(cmd *cobra.Command, args []string) error {
 	if checkpointOptions.Export == "" && checkpointOptions.IgnoreRootFS {
 		return errors.Errorf("--ignore-rootfs can only be used with --export")
 	}
+	if checkpointOptions.Export == "" && checkpointOptions.IgnoreVolumes {
+		return errors.Errorf("--ignore-volumes can only be used with --export")
+	}
 	responses, err := registry.ContainerEngine().ContainerCheckpoint(context.Background(), args, checkpointOptions)
 	if err != nil {
 		return err

cmd/podman/containers/restore.go

@@ -62,6 +62,7 @@ func init() {
 	flags.BoolVar(&restoreOptions.IgnoreRootFS, "ignore-rootfs", false, "Do not apply root file-system changes when importing from exported checkpoint")
 	flags.BoolVar(&restoreOptions.IgnoreStaticIP, "ignore-static-ip", false, "Ignore IP address set via --static-ip")
 	flags.BoolVar(&restoreOptions.IgnoreStaticMAC, "ignore-static-mac", false, "Ignore MAC address set via --mac-address")
+	flags.BoolVar(&restoreOptions.IgnoreVolumes, "ignore-volumes", false, "Do not export volumes associated with container")
 	validate.AddLatestFlag(restoreCommand, &restoreOptions.Latest)
 }
 
@@ -73,6 +74,9 @@ func restore(_ *cobra.Command, args []string) error {
 	if restoreOptions.Import == "" && restoreOptions.IgnoreRootFS {
 		return errors.Errorf("--ignore-rootfs can only be used with --import")
 	}
+	if restoreOptions.Import == "" && restoreOptions.IgnoreVolumes {
+		return errors.Errorf("--ignore-volumes can only be used with --import")
+	}
 	if restoreOptions.Import == "" && restoreOptions.Name != "" {
 		return errors.Errorf("--name can only be used with --import")
 	}

docs/source/markdown/podman-container-checkpoint.1.md

@@ -52,6 +52,12 @@ exported to a tar.gz file it is possible with the help of **--ignore-rootfs**
 to explicitly disable including changes to the root file-system into
 the checkpoint archive file.
 
+#### **--ignore-volumes**
+
+This option must be used in combination with the **--export, -e** option.
+When this option is specified, the content of volumes associated with
+the container will not be included into the checkpoint tar.gz file.
+
 ## EXAMPLE
 
 podman container checkpoint mywebserver

docs/source/markdown/podman-container-restore.1.md

@@ -85,6 +85,13 @@ exported checkpoint with **--name, -n**.
 
 Using **--ignore-static-mac** tells Podman to ignore the MAC address if it was
 configured with **--mac-address** during container creation.
+
+#### **--ignore-volumes**
+
+This option must be used in combination with the **--import, -i** option.
+When restoring containers from a checkpoint tar.gz file with this option,
+the content of associated volumes will not be restored.
+
 ## EXAMPLE
 
 podman container restore mywebserver

libpod/container_api.go

@@ -703,6 +703,9 @@ type ContainerCheckpointOptions struct {
 	// important to be able to restore a container multiple
 	// times with '--import --name'.
 	IgnoreStaticMAC bool
+	// IgnoreVolumes tells the API to not export or not to import
+	// the content of volumes associated with the container
+	IgnoreVolumes bool
 }
 
 // Checkpoint checkpoints a container

libpod/container_internal_linux.go

@@ -790,11 +790,11 @@ func (c *Container) addNamespaceContainer(g *generate.Generator, ns LinuxNS, ctr
 	return nil
 }
 
-func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) error {
-	if (len(c.config.NamedVolumes) > 0) || (len(c.Dependencies()) > 0) {
-		return errors.Errorf("Cannot export checkpoints of containers with named volumes or dependencies")
+func (c *Container) exportCheckpoint(options ContainerCheckpointOptions) error {
+	if len(c.Dependencies()) > 0 {
+		return errors.Errorf("Cannot export checkpoints of containers with dependencies")
 	}
-	logrus.Debugf("Exporting checkpoint image of container %q to %q", c.ID(), dest)
+	logrus.Debugf("Exporting checkpoint image of container %q to %q", c.ID(), options.TargetFile)
 
 	includeFiles := []string{
 		"checkpoint",
@@ -807,7 +807,7 @@ func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) error {
 	// Get root file-system changes included in the checkpoint archive
 	rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar")
 	deleteFilesList := filepath.Join(c.bundlePath(), "deleted.files")
-	if !ignoreRootfs {
+	if !options.IgnoreRootfs {
 		// To correctly track deleted files, let's go through the output of 'podman diff'
 		tarFiles, err := c.runtime.GetDiff("", c.ID())
 		if err != nil {
@@ -870,6 +870,47 @@ func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) error {
 		}
 	}
 
+	// Folder containing archived volumes that will be included in the export
+	expVolDir := filepath.Join(c.bundlePath(), "volumes")
+
+	// Create an archive for each volume associated with the container
+	if !options.IgnoreVolumes {
+		if err := os.MkdirAll(expVolDir, 0700); err != nil {
+			return errors.Wrapf(err, "error creating volumes export directory %q", expVolDir)
+		}
+
+		for _, v := range c.config.NamedVolumes {
+			volumeTarFilePath := filepath.Join("volumes", v.Name+".tar")
+			volumeTarFileFullPath := filepath.Join(c.bundlePath(), volumeTarFilePath)
+
+			volumeTarFile, err := os.Create(volumeTarFileFullPath)
+			if err != nil {
+				return errors.Wrapf(err, "error creating %q", volumeTarFileFullPath)
+			}
+
+			volume, err := c.runtime.GetVolume(v.Name)
+			if err != nil {
+				return err
+			}
+
+			input, err := archive.TarWithOptions(volume.MountPoint(), &archive.TarOptions{
+				Compression:      archive.Uncompressed,
+				IncludeSourceDir: true,
+			})
+			if err != nil {
+				return errors.Wrapf(err, "error reading volume directory %q", v.Dest)
+			}
+
+			_, err = io.Copy(volumeTarFile, input)
+			if err != nil {
+				return err
+			}
+			volumeTarFile.Close()
+
+			includeFiles = append(includeFiles, volumeTarFilePath)
+		}
+	}
+
 	input, err := archive.TarWithOptions(c.bundlePath(), &archive.TarOptions{
 		Compression:      archive.Gzip,
 		IncludeSourceDir: true,
@@ -880,13 +921,13 @@ func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) error {
 		return errors.Wrapf(err, "error reading checkpoint directory %q", c.ID())
 	}
 
-	outFile, err := os.Create(dest)
+	outFile, err := os.Create(options.TargetFile)
 	if err != nil {
-		return errors.Wrapf(err, "error creating checkpoint export file %q", dest)
+		return errors.Wrapf(err, "error creating checkpoint export file %q", options.TargetFile)
 	}
 	defer outFile.Close()
 
-	if err := os.Chmod(dest, 0600); err != nil {
+	if err := os.Chmod(options.TargetFile, 0600); err != nil {
 		return err
 	}
 
@@ -898,6 +939,10 @@ func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) error {
 	os.Remove(rootfsDiffPath)
 	os.Remove(deleteFilesList)
 
+	if !options.IgnoreVolumes {
+		os.RemoveAll(expVolDir)
+	}
+
 	return nil
 }
 
@@ -963,7 +1008,7 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO
 	defer c.newContainerEvent(events.Checkpoint)
 
 	if options.TargetFile != "" {
-		if err = c.exportCheckpoint(options.TargetFile, options.IgnoreRootfs); err != nil {
+		if err = c.exportCheckpoint(options); err != nil {
 			return err
 		}
 	}
@@ -1193,6 +1238,30 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 		return err
 	}
 
+	// When restoring from an imported archive, allow restoring the content of volumes.
+	// Volumes are created in setupContainer()
+	if options.TargetFile != "" && !options.IgnoreVolumes {
+		for _, v := range c.config.NamedVolumes {
+			volumeFilePath := filepath.Join(c.bundlePath(), "volumes", v.Name+".tar")
+
+			volumeFile, err := os.Open(volumeFilePath)
+			if err != nil {
+				return errors.Wrapf(err, "Failed to open volume file %s", volumeFilePath)
+			}
+			defer volumeFile.Close()
+
+			volume, err := c.runtime.GetVolume(v.Name)
+			if err != nil {
+				return errors.Wrapf(err, "Failed to retrieve volume %s", v.Name)
+			}
+
+			mountPoint := volume.MountPoint()
+			if err := archive.UntarUncompressed(volumeFile, mountPoint, nil); err != nil {
+				return errors.Wrapf(err, "Failed to extract volume %s to %s", volumeFilePath, mountPoint)
+			}
+		}
+	}
+
 	// Before actually restarting the container, apply the root file-system changes
 	if !options.IgnoreRootfs {
 		rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar")

pkg/api/handlers/libpod/containers.go

@@ -275,6 +275,7 @@ func Restore(w http.ResponseWriter, r *http.Request) {
 		Import          bool   `schema:"import"`
 		Name            string `schema:"name"`
 		IgnoreRootFS    bool   `schema:"ignoreRootFS"`
+		IgnoreVolumes   bool   `schema:"ignoreVolumes"`
 		IgnoreStaticIP  bool   `schema:"ignoreStaticIP"`
 		IgnoreStaticMAC bool   `schema:"ignoreStaticMAC"`
 	}{

pkg/checkpoint/checkpoint_restore.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/containers/podman/v2/libpod"
 	"github.com/containers/podman/v2/libpod/image"
+	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/containers/podman/v2/pkg/errorhandling"
 	"github.com/containers/podman/v2/pkg/util"
 	"github.com/containers/storage/pkg/archive"
@@ -36,10 +37,10 @@ func crImportFromJSON(filePath string, v interface{}) error {
 
 // CRImportCheckpoint it the function which imports the information
 // from checkpoint tarball and re-creates the container from that information
-func CRImportCheckpoint(ctx context.Context, runtime *libpod.Runtime, input string, name string) ([]*libpod.Container, error) {
+func CRImportCheckpoint(ctx context.Context, runtime *libpod.Runtime, restoreOptions entities.RestoreOptions) ([]*libpod.Container, error) {
 	// First get the container definition from the
 	// tarball to a temporary directory
-	archiveFile, err := os.Open(input)
+	archiveFile, err := os.Open(restoreOptions.Import)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to open checkpoint archive for import")
 	}
@@ -53,6 +54,7 @@ func CRImportCheckpoint(ctx context.Context, runtime *libpod.Runtime, input stri
 			"rootfs-diff.tar",
 			"network.status",
 			"deleted.files",
+			"volumes",
 		},
 	}
 	dir, err := ioutil.TempDir("", "checkpoint")
@@ -66,7 +68,7 @@ func CRImportCheckpoint(ctx context.Context, runtime *libpod.Runtime, input stri
 	}()
 	err = archive.Untar(archiveFile, dir, options)
 	if err != nil {
-		return nil, errors.Wrapf(err, "Unpacking of checkpoint archive %s failed", input)
+		return nil, errors.Wrapf(err, "Unpacking of checkpoint archive %s failed", restoreOptions.Import)
 	}
 
 	// Load spec.dump from temporary directory
@@ -82,17 +84,30 @@ func CRImportCheckpoint(ctx context.Context, runtime *libpod.Runtime, input stri
 	}
 
 	// This should not happen as checkpoints with these options are not exported.
-	if (len(config.Dependencies) > 0) || (len(config.NamedVolumes) > 0) {
-		return nil, errors.Errorf("Cannot import checkpoints of containers with named volumes or dependencies")
+	if len(config.Dependencies) > 0 {
+		return nil, errors.Errorf("Cannot import checkpoints of containers with dependencies")
+	}
+
+	// Volumes included in the checkpoint should not exist
+	if !restoreOptions.IgnoreVolumes {
+		for _, vol := range config.NamedVolumes {
+			exists, err := runtime.HasVolume(vol.Name)
+			if err != nil {
+				return nil, err
+			}
+			if exists {
+				return nil, errors.Errorf("volume with name %s already exists. Use --ignore-volumes to not restore content of volumes", vol.Name)
+			}
+		}
 	}
 
 	ctrID := config.ID
 	newName := false
 
 	// Check if the restored container gets a new name
-	if name != "" {
+	if restoreOptions.Name != "" {
 		config.ID = ""
-		config.Name = name
+		config.Name = restoreOptions.Name
 		newName = true
 	}
 

pkg/domain/entities/containers.go

@@ -173,6 +173,7 @@ type CheckpointOptions struct {
 	All            bool
 	Export         string
 	IgnoreRootFS   bool
+	IgnoreVolumes  bool
 	Keep           bool
 	Latest         bool
 	LeaveRunning   bool
@@ -187,6 +188,7 @@ type CheckpointReport struct {
 type RestoreOptions struct {
 	All             bool
 	IgnoreRootFS    bool
+	IgnoreVolumes   bool
 	IgnoreStaticIP  bool
 	IgnoreStaticMAC bool
 	Import          string

pkg/domain/infra/abi/containers.go

@@ -487,6 +487,7 @@ func (ic *ContainerEngine) ContainerCheckpoint(ctx context.Context, namesOrIds [
 		TCPEstablished: options.TCPEstablished,
 		TargetFile:     options.Export,
 		IgnoreRootfs:   options.IgnoreRootFS,
+		IgnoreVolumes:  options.IgnoreVolumes,
 		KeepRunning:    options.LeaveRunning,
 	}
 
@@ -525,6 +526,7 @@ func (ic *ContainerEngine) ContainerRestore(ctx context.Context, namesOrIds []st
 		TargetFile:      options.Import,
 		Name:            options.Name,
 		IgnoreRootfs:    options.IgnoreRootFS,
+		IgnoreVolumes:   options.IgnoreVolumes,
 		IgnoreStaticIP:  options.IgnoreStaticIP,
 		IgnoreStaticMAC: options.IgnoreStaticMAC,
 	}
@@ -538,7 +540,7 @@ func (ic *ContainerEngine) ContainerRestore(ctx context.Context, namesOrIds []st
 
 	switch {
 	case options.Import != "":
-		cons, err = checkpoint.CRImportCheckpoint(ctx, ic.Libpod, options.Import, options.Name)
+		cons, err = checkpoint.CRImportCheckpoint(ctx, ic.Libpod, options)
 	case options.All:
 		cons, err = ic.Libpod.GetContainers(filterFuncs...)
 	default:

test/e2e/build/basicalpine/Containerfile.volume

@@ -0,0 +1,2 @@
+FROM alpine
+VOLUME "/volume0"