From 288ccc4c84e917df0ff0ee659f47e3ecbc87796a Mon Sep 17 00:00:00 2001 From: Radostin Stoyanov Date: Fri, 18 Dec 2020 20:07:08 +0000 Subject: [PATCH] Include named volumes in container migration When migrating a container with associated volumes, the content of these volumes should be made available on the destination machine. This patch enables container checkpoint/restore with named volumes by including the content of volumes in checkpoint file. On restore, volumes associated with container are created and their content is restored. The --ignore-volumes option is introduced to disable this feature. Example: # podman container checkpoint --export checkpoint.tar.gz The content of all volumes associated with the container are included in `checkpoint.tar.gz` # podman container checkpoint --export checkpoint.tar.gz --ignore-volumes The content of volumes is not included in `checkpoint.tar.gz`. This is useful, for example, when the checkpoint/restore is performed on the same machine. # podman container restore --import checkpoint.tar.gz The associated volumes will be created and their content will be restored. Podman will exit with an error if volumes with the same name already exist on the system or the content of volumes is not included in checkpoint.tar.gz # podman container restore --ignore-volumes --import checkpoint.tar.gz Volumes associated with container must already exist. Podman will not create them or restore their content. Signed-off-by: Radostin Stoyanov --- cmd/podman/containers/checkpoint.go | 4 + cmd/podman/containers/restore.go | 4 + .../markdown/podman-container-checkpoint.1.md | 6 ++ .../markdown/podman-container-restore.1.md | 7 ++ libpod/container_api.go | 3 + libpod/container_internal_linux.go | 73 ++++++++++++++++++- pkg/api/handlers/libpod/containers.go | 1 + pkg/checkpoint/checkpoint_restore.go | 18 ++++- pkg/domain/entities/containers.go | 2 + pkg/domain/infra/abi/containers.go | 2 + 10 files changed, 116 insertions(+), 4 deletions(-) diff --git a/cmd/podman/containers/checkpoint.go b/cmd/podman/containers/checkpoint.go index b6dc213487..4a477eb10f 100644 --- a/cmd/podman/containers/checkpoint.go +++ b/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 diff --git a/cmd/podman/containers/restore.go b/cmd/podman/containers/restore.go index 6a1d2b3190..5245a68fa2 100644 --- a/cmd/podman/containers/restore.go +++ b/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") } diff --git a/docs/source/markdown/podman-container-checkpoint.1.md b/docs/source/markdown/podman-container-checkpoint.1.md index bfda782c50..6a94691562 100644 --- a/docs/source/markdown/podman-container-checkpoint.1.md +++ b/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 diff --git a/docs/source/markdown/podman-container-restore.1.md b/docs/source/markdown/podman-container-restore.1.md index 494e7db1ec..0593e6fe9f 100644 --- a/docs/source/markdown/podman-container-restore.1.md +++ b/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 diff --git a/libpod/container_api.go b/libpod/container_api.go index c3e1a23d23..2c7dc79c9c 100644 --- a/libpod/container_api.go +++ b/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 diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index 9dd39ac8cb..f947d1ed98 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -791,8 +791,8 @@ func (c *Container) addNamespaceContainer(g *generate.Generator, ns LinuxNS, ctr } func (c *Container) exportCheckpoint(options ContainerCheckpointOptions) error { - if (len(c.config.NamedVolumes) > 0) || (len(c.Dependencies()) > 0) { - return errors.Errorf("Cannot export checkpoints of containers with named volumes or dependencies") + 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(), options.TargetFile) @@ -870,6 +870,47 @@ func (c *Container) exportCheckpoint(options ContainerCheckpointOptions) 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, @@ -898,6 +939,10 @@ func (c *Container) exportCheckpoint(options ContainerCheckpointOptions) error { os.Remove(rootfsDiffPath) os.Remove(deleteFilesList) + if !options.IgnoreVolumes { + os.RemoveAll(expVolDir) + } + return nil } @@ -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") diff --git a/pkg/api/handlers/libpod/containers.go b/pkg/api/handlers/libpod/containers.go index 14eb44831e..6b07b1cc5d 100644 --- a/pkg/api/handlers/libpod/containers.go +++ b/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"` }{ diff --git a/pkg/checkpoint/checkpoint_restore.go b/pkg/checkpoint/checkpoint_restore.go index 90f629354e..f6cd3b38f5 100644 --- a/pkg/checkpoint/checkpoint_restore.go +++ b/pkg/checkpoint/checkpoint_restore.go @@ -54,6 +54,7 @@ func CRImportCheckpoint(ctx context.Context, runtime *libpod.Runtime, restoreOpt "rootfs-diff.tar", "network.status", "deleted.files", + "volumes", }, } dir, err := ioutil.TempDir("", "checkpoint") @@ -83,8 +84,21 @@ func CRImportCheckpoint(ctx context.Context, runtime *libpod.Runtime, restoreOpt } // 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 diff --git a/pkg/domain/entities/containers.go b/pkg/domain/entities/containers.go index 05b9b774eb..a67ecebd56 100644 --- a/pkg/domain/entities/containers.go +++ b/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 diff --git a/pkg/domain/infra/abi/containers.go b/pkg/domain/infra/abi/containers.go index 721a8c3ab8..f7a5389340 100644 --- a/pkg/domain/infra/abi/containers.go +++ b/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, }