Prepare cri for merge to containerd

Signed-off-by: Derek McGowan <derek@mcg.dev>

pkg/cri/cri.go

@@ -0,0 +1,192 @@
+/*
+   Copyright The containerd 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 cri
+
+import (
+	"flag"
+	"path/filepath"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/api/services/containers/v1"
+	"github.com/containerd/containerd/api/services/diff/v1"
+	"github.com/containerd/containerd/api/services/images/v1"
+	introspectionapi "github.com/containerd/containerd/api/services/introspection/v1"
+	"github.com/containerd/containerd/api/services/namespaces/v1"
+	"github.com/containerd/containerd/api/services/tasks/v1"
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/leases"
+	"github.com/containerd/containerd/log"
+	"github.com/containerd/containerd/platforms"
+	"github.com/containerd/containerd/plugin"
+	"github.com/containerd/containerd/services"
+	"github.com/containerd/containerd/snapshots"
+	imagespec "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"k8s.io/klog/v2"
+
+	criconfig "github.com/containerd/cri/pkg/config"
+	"github.com/containerd/cri/pkg/constants"
+	criplatforms "github.com/containerd/cri/pkg/containerd/platforms"
+	"github.com/containerd/cri/pkg/server"
+)
+
+// TODO(random-liu): Use github.com/pkg/errors for our errors.
+// Register CRI service plugin
+func init() {
+	config := criconfig.DefaultConfig()
+	plugin.Register(&plugin.Registration{
+		Type:   plugin.GRPCPlugin,
+		ID:     "cri",
+		Config: &config,
+		Requires: []plugin.Type{
+			plugin.ServicePlugin,
+		},
+		InitFn: initCRIService,
+	})
+}
+
+func initCRIService(ic *plugin.InitContext) (interface{}, error) {
+	ic.Meta.Platforms = []imagespec.Platform{platforms.DefaultSpec()}
+	ic.Meta.Exports = map[string]string{"CRIVersion": constants.CRIVersion}
+	ctx := ic.Context
+	pluginConfig := ic.Config.(*criconfig.PluginConfig)
+	if err := criconfig.ValidatePluginConfig(ctx, pluginConfig); err != nil {
+		return nil, errors.Wrap(err, "invalid plugin config")
+	}
+
+	c := criconfig.Config{
+		PluginConfig:       *pluginConfig,
+		ContainerdRootDir:  filepath.Dir(ic.Root),
+		ContainerdEndpoint: ic.Address,
+		RootDir:            ic.Root,
+		StateDir:           ic.State,
+	}
+	log.G(ctx).Infof("Start cri plugin with config %+v", c)
+
+	if err := setGLogLevel(); err != nil {
+		return nil, errors.Wrap(err, "failed to set glog level")
+	}
+
+	servicesOpts, err := getServicesOpts(ic)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to get services")
+	}
+
+	log.G(ctx).Info("Connect containerd service")
+	client, err := containerd.New(
+		"",
+		containerd.WithDefaultNamespace(constants.K8sContainerdNamespace),
+		containerd.WithDefaultPlatform(criplatforms.Default()),
+		containerd.WithServices(servicesOpts...),
+	)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to create containerd client")
+	}
+
+	s, err := server.NewCRIService(c, client)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to create CRI service")
+	}
+
+	go func() {
+		if err := s.Run(); err != nil {
+			log.G(ctx).WithError(err).Fatal("Failed to run CRI service")
+		}
+		// TODO(random-liu): Whether and how we can stop containerd.
+	}()
+	return s, nil
+}
+
+// getServicesOpts get service options from plugin context.
+func getServicesOpts(ic *plugin.InitContext) ([]containerd.ServicesOpt, error) {
+	plugins, err := ic.GetByType(plugin.ServicePlugin)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to get service plugin")
+	}
+
+	opts := []containerd.ServicesOpt{
+		containerd.WithEventService(ic.Events),
+	}
+	for s, fn := range map[string]func(interface{}) containerd.ServicesOpt{
+		services.ContentService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithContentStore(s.(content.Store))
+		},
+		services.ImagesService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithImageService(s.(images.ImagesClient))
+		},
+		services.SnapshotsService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithSnapshotters(s.(map[string]snapshots.Snapshotter))
+		},
+		services.ContainersService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithContainerService(s.(containers.ContainersClient))
+		},
+		services.TasksService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithTaskService(s.(tasks.TasksClient))
+		},
+		services.DiffService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithDiffService(s.(diff.DiffClient))
+		},
+		services.NamespacesService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithNamespaceService(s.(namespaces.NamespacesClient))
+		},
+		services.LeasesService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithLeasesService(s.(leases.Manager))
+		},
+		services.IntrospectionService: func(s interface{}) containerd.ServicesOpt {
+			return containerd.WithIntrospectionService(s.(introspectionapi.IntrospectionClient))
+		},
+	} {
+		p := plugins[s]
+		if p == nil {
+			return nil, errors.Errorf("service %q not found", s)
+		}
+		i, err := p.Instance()
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to get instance of service %q", s)
+		}
+		if i == nil {
+			return nil, errors.Errorf("instance of service %q not found", s)
+		}
+		opts = append(opts, fn(i))
+	}
+	return opts, nil
+}
+
+// Set glog level.
+func setGLogLevel() error {
+	l := logrus.GetLevel()
+	fs := flag.NewFlagSet("klog", flag.PanicOnError)
+	klog.InitFlags(fs)
+	if err := fs.Set("logtostderr", "true"); err != nil {
+		return err
+	}
+	switch l {
+	case logrus.TraceLevel:
+		return fs.Set("v", "5")
+	case logrus.DebugLevel:
+		return fs.Set("v", "4")
+	case logrus.InfoLevel:
+		return fs.Set("v", "2")
+	// glog doesn't support following filters. Defaults to v=0.
+	case logrus.WarnLevel:
+	case logrus.ErrorLevel:
+	case logrus.FatalLevel:
+	case logrus.PanicLevel:
+	}
+	return nil
+}