All handlers of containerd containers share a single client instance

Signed-off-by: Yanqiang Miao <miao.yanqiang@zte.com.cn>

container/containerd/client.go

@@ -16,6 +16,7 @@ package containerd
 
 import (
 	"context"
+	"sync"
 	"time"
 
 	containersapi "github.com/containerd/containerd/api/services/containers/v1"
@@ -45,11 +46,15 @@ type containerdClient interface {
 	Version(ctx context.Context) (string, error)
 }
 
+var once sync.Once
+var ctrdClient containerdClient = nil
+
 // Client creates a containerd client
 func Client() (containerdClient, error) {
+	var retErr error
+	once.Do(func() {
 		gopts := []grpc.DialOption{
 			grpc.WithInsecure(),
-		grpc.FailOnNonTempDialError(true),
 			grpc.WithDialer(dialer.Dialer),
 			grpc.WithBlock(),
 			grpc.WithTimeout(2 * time.Second),
@@ -63,14 +68,16 @@ func Client() (containerdClient, error) {
 
 		conn, err := grpc.Dial(dialer.DialAddress("/var/run/containerd/containerd.sock"), gopts...)
 		if err != nil {
-		return nil, err
+			retErr = err
+			return
 		}
-	c := &client{
+		ctrdClient = &client{
 			containerService: containersapi.NewContainersClient(conn),
 			taskService:      tasksapi.NewTasksClient(conn),
 			versionService:   versionapi.NewVersionClient(conn),
 		}
-	return c, err
+	})
+	return ctrdClient, retErr
 }
 
 func (c *client) LoadContainer(ctx context.Context, id string) (*containers.Container, error) {