diff options
Diffstat (limited to 'pkg/adapter/checkpoint_restore.go')
-rw-r--r-- | pkg/adapter/checkpoint_restore.go | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/pkg/adapter/checkpoint_restore.go b/pkg/adapter/checkpoint_restore.go new file mode 100644 index 000000000..97ba5ecf7 --- /dev/null +++ b/pkg/adapter/checkpoint_restore.go @@ -0,0 +1,145 @@ +// +build !remoteclient + +package adapter + +import ( + "context" + "github.com/containers/libpod/libpod" + "github.com/containers/libpod/libpod/image" + "github.com/containers/storage/pkg/archive" + jsoniter "github.com/json-iterator/go" + spec "github.com/opencontainers/runtime-spec/specs-go" + "github.com/pkg/errors" + "io" + "io/ioutil" + "os" + "path/filepath" +) + +// Prefixing the checkpoint/restore related functions with 'cr' + +// crImportFromJSON imports the JSON files stored in the exported +// checkpoint tarball +func crImportFromJSON(filePath string, v interface{}) error { + jsonFile, err := os.Open(filePath) + if err != nil { + return errors.Wrapf(err, "Failed to open container definition %s for restore", filePath) + } + defer jsonFile.Close() + + content, err := ioutil.ReadAll(jsonFile) + if err != nil { + return errors.Wrapf(err, "Failed to read container definition %s for restore", filePath) + } + json := jsoniter.ConfigCompatibleWithStandardLibrary + if err = json.Unmarshal([]byte(content), v); err != nil { + return errors.Wrapf(err, "Failed to unmarshal container definition %s for restore", filePath) + } + + return nil +} + +// 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) { + // First get the container definition from the + // tarball to a temporary directory + archiveFile, err := os.Open(input) + if err != nil { + return nil, errors.Wrapf(err, "Failed to open checkpoint archive %s for import", input) + } + defer archiveFile.Close() + options := &archive.TarOptions{ + // Here we only need the files config.dump and spec.dump + ExcludePatterns: []string{ + "checkpoint", + "artifacts", + "ctr.log", + "network.status", + }, + } + dir, err := ioutil.TempDir("", "checkpoint") + if err != nil { + return nil, err + } + defer os.RemoveAll(dir) + err = archive.Untar(archiveFile, dir, options) + if err != nil { + return nil, errors.Wrapf(err, "Unpacking of checkpoint archive %s failed", input) + } + + // Load spec.dump from temporary directory + spec := new(spec.Spec) + if err := crImportFromJSON(filepath.Join(dir, "spec.dump"), spec); err != nil { + return nil, err + } + + // Load config.dump from temporary directory + config := new(libpod.ContainerConfig) + if err = crImportFromJSON(filepath.Join(dir, "config.dump"), config); err != nil { + return nil, err + } + + // 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") + } + + ctrID := config.ID + newName := false + + // Check if the restored container gets a new name + if name != "" { + config.ID = "" + config.Name = name + newName = true + } + + ctrName := config.Name + + // The code to load the images is copied from create.go + var writer io.Writer + // In create.go this only set if '--quiet' does not exist. + writer = os.Stderr + rtc, err := runtime.GetConfig() + if err != nil { + return nil, err + } + + _, err = runtime.ImageRuntime().New(ctx, config.RootfsImageName, rtc.SignaturePolicyPath, "", writer, nil, image.SigningOptions{}, false, nil) + if err != nil { + return nil, err + } + + // Now create a new container from the just loaded information + container, err := runtime.RestoreContainer(ctx, spec, config) + if err != nil { + return nil, err + } + + var containers []*libpod.Container + if container == nil { + return nil, nil + } + + containerConfig := container.Config() + if containerConfig.Name != ctrName { + return nil, errors.Errorf("Name of restored container (%s) does not match requested name (%s)", containerConfig.Name, ctrName) + } + + if newName == false { + // Only check ID for a restore with the same name. + // Using -n to request a new name for the restored container, will also create a new ID + if containerConfig.ID != ctrID { + return nil, errors.Errorf("ID of restored container (%s) does not match requested ID (%s)", containerConfig.ID, ctrID) + } + } + + // Check if the ExitCommand points to the correct container ID + if containerConfig.ExitCommand[len(containerConfig.ExitCommand)-1] != containerConfig.ID { + return nil, errors.Errorf("'ExitCommandID' uses ID %s instead of container ID %s", containerConfig.ExitCommand[len(containerConfig.ExitCommand)-1], containerConfig.ID) + } + + containers = append(containers, container) + return containers, nil +} |