Add container metadata store.

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/metadata/container.go

@@ -0,0 +1,183 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package metadata
+
+import (
+	"encoding/json"
+
+	"github.com/kubernetes-incubator/cri-containerd/pkg/metadata/store"
+
+	"k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
+)
+
+// The code is very similar with sandbox.go, but there is no template support
+// in golang, we have to have similar files for different types.
+// TODO(random-liu): Figure out a way to simplify this.
+// TODO(random-liu): Handle versioning with the same mechanism with container.go
+
+// containerMetadataVersion  is current version of container metadata.
+const containerMetadataVersion = "v1" // nolint
+
+// versionedContainerMetadata is the internal versioned container metadata.
+// nolint
+type versionedContainerMetadata struct {
+	// Version indicates the version of the versioned container metadata.
+	Version string
+	ContainerMetadata
+}
+
+// ContainerMetadata is the unversioned container metadata.
+type ContainerMetadata struct {
+	// ID is the container id.
+	ID string
+	// Name is the container name.
+	Name string
+	// SandboxID is the sandbox id the container belongs to.
+	SandboxID string
+	// Config is the CRI container config.
+	Config *runtime.ContainerConfig
+	// ImageRef is the reference of image used by the container.
+	ImageRef string
+	// Pid is the init process id of the container.
+	Pid uint32
+	// CreatedAt is the created timestamp.
+	CreatedAt int64
+	// StartedAt is the started timestamp.
+	StartedAt int64
+	// FinishedAt is the finished timestamp.
+	FinishedAt int64
+	// ExitCode is the container exit code.
+	ExitCode int32
+	// CamelCase string explaining why container is in its current state.
+	Reason string
+	// Human-readable message indicating details about why container is in its
+	// current state.
+	Message string
+	// Removing indicates that the container is in removing state.
+	// In fact, this field doesn't need to be checkpointed.
+	// TODO(random-liu): Skip this during serialization when we put object
+	// into the store directly.
+	// TODO(random-liu): Reset this field to false during state recoverry.
+	Removing bool
+}
+
+// State returns current state of the container based on the metadata.
+func (c *ContainerMetadata) State() runtime.ContainerState {
+	if c.FinishedAt != 0 {
+		return runtime.ContainerState_CONTAINER_EXITED
+	}
+	if c.StartedAt != 0 {
+		return runtime.ContainerState_CONTAINER_RUNNING
+	}
+	if c.CreatedAt != 0 {
+		return runtime.ContainerState_CONTAINER_CREATED
+	}
+	return runtime.ContainerState_CONTAINER_UNKNOWN
+}
+
+// ContainerUpdateFunc is the function used to update ContainerMetadata.
+type ContainerUpdateFunc func(ContainerMetadata) (ContainerMetadata, error)
+
+// ContainerToStoreUpdateFunc generates a metadata store UpdateFunc from ContainerUpdateFunc.
+func ContainerToStoreUpdateFunc(u ContainerUpdateFunc) store.UpdateFunc {
+	return func(data []byte) ([]byte, error) {
+		meta := &ContainerMetadata{}
+		if err := json.Unmarshal(data, meta); err != nil {
+			return nil, err
+		}
+		newMeta, err := u(*meta)
+		if err != nil {
+			return nil, err
+		}
+		return json.Marshal(newMeta)
+	}
+}
+
+// ContainerStore is the store for metadata of all containers.
+type ContainerStore interface {
+	// Create creates a container from ContainerMetadata in the store.
+	Create(ContainerMetadata) error
+	// Get gets a specified container.
+	Get(string) (*ContainerMetadata, error)
+	// Update updates a specified container.
+	Update(string, ContainerUpdateFunc) error
+	// List lists all containers.
+	List() ([]*ContainerMetadata, error)
+	// Delete deletes the container from the store.
+	Delete(string) error
+}
+
+// containerStore is an implmentation of ContainerStore.
+type containerStore struct {
+	store store.MetadataStore
+}
+
+// NewContainerStore creates a ContainerStore from a basic MetadataStore.
+func NewContainerStore(store store.MetadataStore) ContainerStore {
+	return &containerStore{store: store}
+}
+
+// Create creates a container from ContainerMetadata in the store.
+func (c *containerStore) Create(metadata ContainerMetadata) error {
+	data, err := json.Marshal(&metadata)
+	if err != nil {
+		return err
+	}
+	return c.store.Create(metadata.ID, data)
+}
+
+// Get gets a specified container.
+func (c *containerStore) Get(containerID string) (*ContainerMetadata, error) {
+	data, err := c.store.Get(containerID)
+	if err != nil {
+		return nil, err
+	}
+	container := &ContainerMetadata{}
+	if err := json.Unmarshal(data, container); err != nil {
+		return nil, err
+	}
+	return container, nil
+}
+
+// Update updates a specified container. The function is running in a
+// transaction. Update will not be applied when the update function
+// returns error.
+func (c *containerStore) Update(containerID string, u ContainerUpdateFunc) error {
+	return c.store.Update(containerID, ContainerToStoreUpdateFunc(u))
+}
+
+// List lists all containers.
+func (c *containerStore) List() ([]*ContainerMetadata, error) {
+	allData, err := c.store.List()
+	if err != nil {
+		return nil, err
+	}
+	var containers []*ContainerMetadata
+	for _, data := range allData {
+		container := &ContainerMetadata{}
+		if err := json.Unmarshal(data, container); err != nil {
+			return nil, err
+		}
+		containers = append(containers, container)
+	}
+	return containers, nil
+}
+
+// Delete deletes the Container from the store.
+func (c *containerStore) Delete(containerID string) error {
+	return c.store.Delete(containerID)
+}

pkg/metadata/container_test.go

@@ -0,0 +1,180 @@
+/*
+Copyright 2017 The Kubernetes Authorc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package metadata
+
+import (
+	"testing"
+	"time"
+
+	assertlib "github.com/stretchr/testify/assert"
+
+	"github.com/kubernetes-incubator/cri-containerd/pkg/metadata/store"
+
+	"k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
+)
+
+func TestContainerState(t *testing.T) {
+	for c, test := range map[string]struct {
+		metadata *ContainerMetadata
+		state    runtime.ContainerState
+	}{
+		"unknown state": {
+			metadata: &ContainerMetadata{
+				ID:   "1",
+				Name: "Container-1",
+			},
+			state: runtime.ContainerState_CONTAINER_UNKNOWN,
+		},
+		"created state": {
+			metadata: &ContainerMetadata{
+				ID:        "2",
+				Name:      "Container-2",
+				CreatedAt: time.Now().UnixNano(),
+			},
+			state: runtime.ContainerState_CONTAINER_CREATED,
+		},
+		"running state": {
+			metadata: &ContainerMetadata{
+				ID:        "3",
+				Name:      "Container-3",
+				CreatedAt: time.Now().UnixNano(),
+				StartedAt: time.Now().UnixNano(),
+			},
+			state: runtime.ContainerState_CONTAINER_RUNNING,
+		},
+		"exited state": {
+			metadata: &ContainerMetadata{
+				ID:         "3",
+				Name:       "Container-3",
+				CreatedAt:  time.Now().UnixNano(),
+				FinishedAt: time.Now().UnixNano(),
+			},
+			state: runtime.ContainerState_CONTAINER_EXITED,
+		},
+	} {
+		t.Logf("TestCase %q", c)
+		assertlib.Equal(t, test.state, test.metadata.State())
+	}
+}
+
+func TestContainerStore(t *testing.T) {
+	containers := map[string]*ContainerMetadata{
+		"1": {
+			ID:        "1",
+			Name:      "Container-1",
+			SandboxID: "Sandbox-1",
+			Config: &runtime.ContainerConfig{
+				Metadata: &runtime.ContainerMetadata{
+					Name:    "TestPod-1",
+					Attempt: 1,
+				},
+			},
+			ImageRef:   "TestImage-1",
+			Pid:        1,
+			CreatedAt:  time.Now().UnixNano(),
+			StartedAt:  time.Now().UnixNano(),
+			FinishedAt: time.Now().UnixNano(),
+			ExitCode:   1,
+			Reason:     "TestReason-1",
+			Message:    "TestMessage-1",
+		},
+		"2": {
+			ID:        "2",
+			Name:      "Container-2",
+			SandboxID: "Sandbox-2",
+			Config: &runtime.ContainerConfig{
+				Metadata: &runtime.ContainerMetadata{
+					Name:    "TestPod-2",
+					Attempt: 2,
+				},
+			},
+			ImageRef:   "TestImage-2",
+			Pid:        2,
+			CreatedAt:  time.Now().UnixNano(),
+			StartedAt:  time.Now().UnixNano(),
+			FinishedAt: time.Now().UnixNano(),
+			ExitCode:   2,
+			Reason:     "TestReason-2",
+			Message:    "TestMessage-2",
+		},
+		"3": {
+			ID:        "3",
+			Name:      "Container-3",
+			SandboxID: "Sandbox-3",
+			Config: &runtime.ContainerConfig{
+				Metadata: &runtime.ContainerMetadata{
+					Name:    "TestPod-3",
+					Attempt: 3,
+				},
+			},
+			ImageRef:   "TestImage-3",
+			Pid:        3,
+			CreatedAt:  time.Now().UnixNano(),
+			StartedAt:  time.Now().UnixNano(),
+			FinishedAt: time.Now().UnixNano(),
+			ExitCode:   3,
+			Reason:     "TestReason-3",
+			Message:    "TestMessage-3",
+			Removing:   true,
+		},
+	}
+	assert := assertlib.New(t)
+
+	c := NewContainerStore(store.NewMetadataStore())
+
+	t.Logf("should be able to create container metadata")
+	for _, meta := range containers {
+		assert.NoError(c.Create(*meta))
+	}
+
+	t.Logf("should be able to get container metadata")
+	for id, expectMeta := range containers {
+		meta, err := c.Get(id)
+		assert.NoError(err)
+		assert.Equal(expectMeta, meta)
+	}
+
+	t.Logf("should be able to list container metadata")
+	cntrs, err := c.List()
+	assert.NoError(err)
+	assert.Len(cntrs, 3)
+
+	t.Logf("should be able to update container metadata")
+	testID := "2"
+	newCreatedAt := time.Now().UnixNano()
+	expectMeta := *containers[testID]
+	expectMeta.CreatedAt = newCreatedAt
+	err = c.Update(testID, func(o ContainerMetadata) (ContainerMetadata, error) {
+		o.CreatedAt = newCreatedAt
+		return o, nil
+	})
+	assert.NoError(err)
+	newMeta, err := c.Get(testID)
+	assert.NoError(err)
+	assert.Equal(&expectMeta, newMeta)
+
+	t.Logf("should be able to delete container metadata")
+	assert.NoError(c.Delete(testID))
+	cntrs, err = c.List()
+	assert.NoError(err)
+	assert.Len(cntrs, 2)
+
+	t.Logf("get should return nil without error after deletion")
+	meta, err := c.Get(testID)
+	assert.Error(store.ErrNotExist, err)
+	assert.True(meta == nil)
+}