diff options
Diffstat (limited to 'libpod')
| -rw-r--r-- | libpod/container_api.go | 9 | ||||
| -rw-r--r-- | libpod/container_internal_linux.go | 62 | ||||
| -rw-r--r-- | libpod/diff.go | 56 |
3 files changed, 113 insertions, 14 deletions
diff --git a/libpod/container_api.go b/libpod/container_api.go index ae181887e..6f530f75f 100644 --- a/libpod/container_api.go +++ b/libpod/container_api.go @@ -801,15 +801,16 @@ type ContainerCheckpointOptions struct { // TCPEstablished tells the API to checkpoint a container // even if it contains established TCP connections TCPEstablished bool - // Export tells the API to write the checkpoint image to - // the filename set in TargetFile - // Import tells the API to read the checkpoint image from - // the filename set in TargetFile + // TargetFile tells the API to read (or write) the checkpoint image + // from (or to) the filename set in TargetFile TargetFile string // Name tells the API that during restore from an exported // checkpoint archive a new name should be used for the // restored container Name string + // IgnoreRootfs tells the API to not export changes to + // the container's root file-system (or to not import) + IgnoreRootfs bool } // Checkpoint checkpoints a container diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index aa477611f..399220b9a 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -510,21 +510,44 @@ func (c *Container) addNamespaceContainer(g *generate.Generator, ns LinuxNS, ctr return nil } -func (c *Container) exportCheckpoint(dest string) (err error) { +func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) (err error) { if (len(c.config.NamedVolumes) > 0) || (len(c.Dependencies()) > 0) { return errors.Errorf("Cannot export checkpoints of containers with named volumes or dependencies") } logrus.Debugf("Exporting checkpoint image of container %q to %q", c.ID(), dest) + + includeFiles := []string{ + "checkpoint", + "artifacts", + "ctr.log", + "config.dump", + "spec.dump", + "network.status"} + + // Get root file-system changes included in the checkpoint archive + rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar") + if !ignoreRootfs { + rootfsDiffFile, err := os.Create(rootfsDiffPath) + if err != nil { + return errors.Wrapf(err, "error creating root file-system diff file %q", rootfsDiffPath) + } + tarStream, err := c.runtime.GetDiffTarStream("", c.ID()) + if err != nil { + return errors.Wrapf(err, "error exporting root file-system diff to %q", rootfsDiffPath) + } + _, err = io.Copy(rootfsDiffFile, tarStream) + if err != nil { + return errors.Wrapf(err, "error exporting root file-system diff to %q", rootfsDiffPath) + } + tarStream.Close() + rootfsDiffFile.Close() + includeFiles = append(includeFiles, "rootfs-diff.tar") + } + input, err := archive.TarWithOptions(c.bundlePath(), &archive.TarOptions{ Compression: archive.Gzip, IncludeSourceDir: true, - IncludeFiles: []string{ - "checkpoint", - "artifacts", - "ctr.log", - "config.dump", - "spec.dump", - "network.status"}, + IncludeFiles: includeFiles, }) if err != nil { @@ -546,6 +569,8 @@ func (c *Container) exportCheckpoint(dest string) (err error) { return err } + os.Remove(rootfsDiffPath) + return nil } @@ -605,7 +630,7 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO } if options.TargetFile != "" { - if err = c.exportCheckpoint(options.TargetFile); err != nil { + if err = c.exportCheckpoint(options.TargetFile, options.IgnoreRootfs); err != nil { return err } } @@ -792,6 +817,23 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti if err := c.saveSpec(g.Spec()); err != nil { return err } + + // Before actually restarting the container, apply the root file-system changes + if !options.IgnoreRootfs { + rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar") + if _, err := os.Stat(rootfsDiffPath); err == nil { + // Only do this if a rootfs-diff.tar actually exists + rootfsDiffFile, err := os.Open(rootfsDiffPath) + if err != nil { + return errors.Wrapf(err, "Failed to open root file-system diff file %s", rootfsDiffPath) + } + if err := c.runtime.ApplyDiffTarStream(c.ID(), rootfsDiffFile); err != nil { + return errors.Wrapf(err, "Failed to apply root file-system diff file %s", rootfsDiffPath) + } + rootfsDiffFile.Close() + } + } + if err := c.ociRuntime.createContainer(c, c.config.CgroupParent, &options); err != nil { return err } @@ -809,7 +851,7 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti if err != nil { logrus.Debugf("Non-fatal: removal of checkpoint directory (%s) failed: %v", c.CheckpointPath(), err) } - cleanup := [...]string{"restore.log", "dump.log", "stats-dump", "stats-restore", "network.status"} + cleanup := [...]string{"restore.log", "dump.log", "stats-dump", "stats-restore", "network.status", "rootfs-diff.tar"} for _, del := range cleanup { file := filepath.Join(c.bundlePath(), del) err = os.Remove(file) diff --git a/libpod/diff.go b/libpod/diff.go index f348e6b81..925bda927 100644 --- a/libpod/diff.go +++ b/libpod/diff.go @@ -1,6 +1,9 @@ package libpod import ( + "archive/tar" + "io" + "github.com/containers/libpod/libpod/layers" "github.com/containers/storage/pkg/archive" "github.com/pkg/errors" @@ -44,6 +47,59 @@ func (r *Runtime) GetDiff(from, to string) ([]archive.Change, error) { return rchanges, err } +// skipFileInTarAchive is an archive.TarModifierFunc function +// which tells archive.ReplaceFileTarWrapper to skip files +// from the tarstream +func skipFileInTarAchive(path string, header *tar.Header, content io.Reader) (*tar.Header, []byte, error) { + return nil, nil, nil +} + +// GetDiffTarStream returns the differences between the two images, layers, or containers. +// It is the same functionality as GetDiff() except that it returns a tarstream +func (r *Runtime) GetDiffTarStream(from, to string) (io.ReadCloser, error) { + toLayer, err := r.getLayerID(to) + if err != nil { + return nil, err + } + fromLayer := "" + if from != "" { + fromLayer, err = r.getLayerID(from) + if err != nil { + return nil, err + } + } + rc, err := r.store.Diff(fromLayer, toLayer, nil) + if err != nil { + return nil, err + } + + // Skip files in the tar archive which are listed + // in containerMounts map. Just as in the GetDiff() + // function from above + filterMap := make(map[string]archive.TarModifierFunc) + for key := range containerMounts { + filterMap[key[1:]] = skipFileInTarAchive + // In the tarstream directories always include a trailing '/'. + // For simplicity this duplicates every entry from + // containerMounts with a trailing '/', as containerMounts + // does not use trailing '/' for directories. + filterMap[key[1:]+"/"] = skipFileInTarAchive + } + + filteredTarStream := archive.ReplaceFileTarWrapper(rc, filterMap) + return filteredTarStream, nil +} + +// ApplyDiffTarStream applies the changes stored in 'diff' to the layer 'to' +func (r *Runtime) ApplyDiffTarStream(to string, diff io.Reader) error { + toLayer, err := r.getLayerID(to) + if err != nil { + return err + } + _, err = r.store.ApplyDiff(toLayer, diff) + return err +} + // GetLayerID gets a full layer id given a full or partial id // If the id matches a container or image, the id of the top layer is returned // If the id matches a layer, the top layer id is returned |