containerd/pkg/server/service.go

/*
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 server

import (
	"fmt"

	"github.com/containerd/containerd"
	"github.com/containerd/containerd/api/services/events/v1"
	"github.com/containerd/containerd/api/services/tasks/v1"
	"github.com/containerd/containerd/content"
	"github.com/containerd/containerd/images"
	"github.com/cri-o/ocicni"
	"github.com/golang/glog"
	"k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
	"k8s.io/kubernetes/pkg/kubelet/server/streaming"

	osinterface "github.com/kubernetes-incubator/cri-containerd/pkg/os"
	"github.com/kubernetes-incubator/cri-containerd/pkg/registrar"
	containerstore "github.com/kubernetes-incubator/cri-containerd/pkg/store/container"
	imagestore "github.com/kubernetes-incubator/cri-containerd/pkg/store/image"
	sandboxstore "github.com/kubernetes-incubator/cri-containerd/pkg/store/sandbox"
)

// k8sContainerdNamespace is the namespace we use to connect containerd.
const k8sContainerdNamespace = "k8s.io"

// CRIContainerdService is the interface implement CRI remote service server.
type CRIContainerdService interface {
	Start()
	runtime.RuntimeServiceServer
	runtime.ImageServiceServer
}

// criContainerdService implements CRIContainerdService.
type criContainerdService struct {
	// os is an interface for all required os operations.
	os osinterface.OS
	// rootDir is the directory for managing cri-containerd files.
	rootDir string
	// sandboxImage is the image to use for sandbox container.
	// TODO(random-liu): Make this configurable via flag.
	sandboxImage string
	// snapshotter is the snapshotter to use in containerd.
	snapshotter string
	// sandboxStore stores all resources associated with sandboxes.
	sandboxStore *sandboxstore.Store
	// sandboxNameIndex stores all sandbox names and make sure each name
	// is unique.
	sandboxNameIndex *registrar.Registrar
	// containerStore stores all resources associated with containers.
	containerStore *containerstore.Store
	// containerNameIndex stores all container names and make sure each
	// name is unique.
	containerNameIndex *registrar.Registrar
	// imageStore stores all resources associated with images.
	imageStore *imagestore.Store
	// taskService is containerd tasks client.
	taskService tasks.TasksClient
	// contentStoreService is the containerd content service client.
	contentStoreService content.Store
	// imageStoreService is the containerd service to store and track
	// image metadata.
	imageStoreService images.Store
	// eventsService is the containerd task service client
	eventService events.EventsClient
	// netPlugin is used to setup and teardown network when run/stop pod sandbox.
	netPlugin ocicni.CNIPlugin
	// client is an instance of the containerd client
	client *containerd.Client
	// streamServer is the streaming server serves container streaming request.
	streamServer streaming.Server
	// cgroupPath in which the cri-containerd is placed in
	cgroupPath string
}

// NewCRIContainerdService returns a new instance of CRIContainerdService
// TODO(random-liu): Add cri-containerd server config to get rid of the long arg list.
func NewCRIContainerdService(
	containerdEndpoint,
	containerdSnapshotter,
	rootDir,
	networkPluginBinDir,
	networkPluginConfDir,
	streamAddress,
	streamPort string,
	cgroupPath string) (CRIContainerdService, error) {
	// TODO(random-liu): [P2] Recover from runtime state and checkpoint.

	client, err := containerd.New(containerdEndpoint, containerd.WithDefaultNamespace(k8sContainerdNamespace))
	if err != nil {
		return nil, fmt.Errorf("failed to initialize containerd client with endpoint %q: %v", containerdEndpoint, err)
	}
	if cgroupPath != "" {
		_, err := loadCgroup(cgroupPath)
		if err != nil {
			return nil, fmt.Errorf("failed to load cgroup for cgroup path %v: %v", cgroupPath, err)
		}
	}

	c := &criContainerdService{
		os:                  osinterface.RealOS{},
		rootDir:             rootDir,
		sandboxImage:        defaultSandboxImage,
		snapshotter:         containerdSnapshotter,
		sandboxStore:        sandboxstore.NewStore(),
		containerStore:      containerstore.NewStore(),
		imageStore:          imagestore.NewStore(),
		sandboxNameIndex:    registrar.NewRegistrar(),
		containerNameIndex:  registrar.NewRegistrar(),
		taskService:         client.TaskService(),
		imageStoreService:   client.ImageService(),
		eventService:        client.EventService(),
		contentStoreService: client.ContentStore(),
		client:              client,
		cgroupPath:          cgroupPath,
	}

	netPlugin, err := ocicni.InitCNI(networkPluginConfDir, networkPluginBinDir)
	if err != nil {
		return nil, fmt.Errorf("failed to initialize cni plugin: %v", err)
	}
	c.netPlugin = netPlugin

	// prepare streaming server
	c.streamServer, err = newStreamServer(c, streamAddress, streamPort)
	if err != nil {
		return nil, fmt.Errorf("failed to create stream server: %v", err)
	}

	return newInstrumentedService(c), nil
}

func (c *criContainerdService) Start() {
	c.startEventMonitor()
	go func() {
		if err := c.streamServer.Start(true); err != nil {
			glog.Errorf("Failed to start streaming server: %v", err)
		}
	}()
}