Merge pull request #772 from 14rcole/kpod-rename

implement kpod rename

libkpod/rename.go

@@ -0,0 +1,114 @@
+package libkpod
+
+import (
+	"encoding/json"
+	"path/filepath"
+
+	"k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
+
+	"github.com/docker/docker/pkg/ioutils"
+	"github.com/kubernetes-incubator/cri-o/oci"
+	"github.com/kubernetes-incubator/cri-o/pkg/annotations"
+	"github.com/opencontainers/runtime-tools/generate"
+)
+
+const configFile = "config.json"
+
+// ContainerRename renames the given container
+func (c *ContainerServer) ContainerRename(container, name string) error {
+	ctr, err := c.LookupContainer(container)
+	if err != nil {
+		return err
+	}
+
+	oldName := ctr.Name()
+	_, err = c.ReserveContainerName(ctr.ID(), name)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			c.ReleaseContainerName(name)
+		} else {
+			c.ReleaseContainerName(oldName)
+		}
+	}()
+
+	// Update state.json
+	if err = c.updateStateName(ctr, name); err != nil {
+		return err
+	}
+
+	// Update config.json
+	configRuntimePath := filepath.Join(ctr.BundlePath(), configFile)
+	if err = updateConfigName(configRuntimePath, name); err != nil {
+		return err
+	}
+	configStoragePath := filepath.Join(ctr.Dir(), configFile)
+	if err = updateConfigName(configStoragePath, name); err != nil {
+		return err
+	}
+
+	// Update containers.json
+	if err = c.store.SetNames(ctr.ID(), []string{name}); err != nil {
+		return err
+	}
+	return nil
+}
+
+func updateConfigName(configPath, name string) error {
+	specgen, err := generate.NewFromFile(configPath)
+	if err != nil {
+		return err
+	}
+	specgen.AddAnnotation(annotations.Name, name)
+	specgen.AddAnnotation(annotations.Metadata, updateMetadata(specgen.Spec().Annotations, name))
+
+	return specgen.SaveToFile(configPath, generate.ExportOptions{})
+}
+
+func (c *ContainerServer) updateStateName(ctr *oci.Container, name string) error {
+	ctr.State().Annotations[annotations.Name] = name
+	ctr.State().Annotations[annotations.Metadata] = updateMetadata(ctr.State().Annotations, name)
+	// This is taken directly from c.ContainerStateToDisk(), which can't be used because of the call to UpdateStatus() in the first line
+	jsonSource, err := ioutils.NewAtomicFileWriter(ctr.StatePath(), 0644)
+	if err != nil {
+		return err
+	}
+	defer jsonSource.Close()
+	enc := json.NewEncoder(jsonSource)
+	return enc.Encode(c.runtime.ContainerStatus(ctr))
+}
+
+// Attempts to update a metadata annotation
+func updateMetadata(specAnnotations map[string]string, name string) string {
+	oldMetadata := specAnnotations[annotations.Metadata]
+	containerType := specAnnotations[annotations.ContainerType]
+	if containerType == "container" {
+		metadata := runtime.ContainerMetadata{}
+		err := json.Unmarshal([]byte(oldMetadata), metadata)
+		if err != nil {
+			return oldMetadata
+		}
+		metadata.Name = name
+		m, err := json.Marshal(metadata)
+		if err != nil {
+			return oldMetadata
+		}
+		return string(m)
+	} else if containerType == "sandbox" {
+		metadata := runtime.PodSandboxMetadata{}
+		err := json.Unmarshal([]byte(oldMetadata), metadata)
+		if err != nil {
+			return oldMetadata
+		}
+		metadata.Name = name
+		m, err := json.Marshal(metadata)
+		if err != nil {
+			return oldMetadata
+		}
+		return string(m)
+	} else {
+		return specAnnotations[annotations.Metadata]
+	}
+}