Add remote runtime/image Close() API

saschagrunert · saschagrunert · commit a1f093092bfe · 2025-07-25T10:48:27.000+02:00
The API allows to shutdown the internal gRPC connection to avoid leaking
resources.

Signed-off-by: Sascha Grunert &lt;sgrunert@redhat.com&gt;
diff --git a/staging/src/k8s.io/cri-api/pkg/apis/services.go b/staging/src/k8s.io/cri-api/pkg/apis/services.go
@@ -123,6 +123,8 @@ type RuntimeService interface {
 	Status(ctx context.Context, verbose bool) (*runtimeapi.StatusResponse, error)
 	// RuntimeConfig returns the configuration information of the runtime.
 	RuntimeConfig(ctx context.Context) (*runtimeapi.RuntimeConfigResponse, error)
+	// Close will shutdown the internal gRPC client connection.
+	Close() error
 }
 
 // ImageManagerService interface should be implemented by a container image
@@ -139,4 +141,6 @@ type ImageManagerService interface {
 	RemoveImage(ctx context.Context, image *runtimeapi.ImageSpec) error
 	// ImageFsInfo returns information of the filesystem(s) used to store the read-only layers and the writeable layer.
 	ImageFsInfo(ctx context.Context) (*runtimeapi.ImageFsInfoResponse, error)
+	// Close will shutdown the internal gRPC client connection.
+	Close() error
 }
diff --git a/staging/src/k8s.io/cri-client/pkg/remote_image.go b/staging/src/k8s.io/cri-client/pkg/remote_image.go
@@ -44,6 +44,7 @@ type remoteImageService struct {
 	timeout     time.Duration
 	imageClient runtimeapi.ImageServiceClient
 	logger      *klog.Logger
+	conn        *grpc.ClientConn
 }
 
 // NewRemoteImageService creates a new internalapi.ImageManagerService.
@@ -94,6 +95,7 @@ func NewRemoteImageService(endpoint string, connectionTimeout time.Duration, tp
 	service := &remoteImageService{
 		timeout: connectionTimeout,
 		logger:  logger,
+		conn:    conn,
 	}
 	if err := service.validateServiceConnection(ctx, conn, endpoint); err != nil {
 		return nil, fmt.Errorf("validate service connection: %w", err)
@@ -103,6 +105,14 @@ func NewRemoteImageService(endpoint string, connectionTimeout time.Duration, tp
 
 }
 
+// Close will shutdown the internal GRPC client connection.
+func (r *remoteImageService) Close() error {
+	if r.conn != nil {
+		return r.conn.Close()
+	}
+	return nil
+}
+
 func (r *remoteImageService) log(level int, msg string, keyAndValues ...any) {
 	internal.Log(r.logger, level, msg, keyAndValues...)
 }
diff --git a/staging/src/k8s.io/cri-client/pkg/remote_runtime.go b/staging/src/k8s.io/cri-client/pkg/remote_runtime.go
@@ -50,6 +50,7 @@ type remoteRuntimeService struct {
 	// Cache last per-container error message to reduce log spam
 	logReduction *logreduction.LogReduction
 	logger       *klog.Logger
+	conn         *grpc.ClientConn
 }
 
 const (
@@ -127,6 +128,7 @@ func NewRemoteRuntimeService(endpoint string, connectionTimeout time.Duration, t
 		timeout:      connectionTimeout,
 		logReduction: logreduction.NewLogReduction(identicalErrorDelay),
 		logger:       logger,
+		conn:         conn,
 	}
 
 	if err := service.validateServiceConnection(ctx, conn, endpoint); err != nil {
@@ -136,6 +138,14 @@ func NewRemoteRuntimeService(endpoint string, connectionTimeout time.Duration, t
 	return service, nil
 }
 
+// Close will shutdown the internal GRPC client connection.
+func (r *remoteRuntimeService) Close() error {
+	if r.conn != nil {
+		return r.conn.Close()
+	}
+	return nil
+}
+
 func (r *remoteRuntimeService) log(level int, msg string, keyAndValues ...any) {
 	internal.Log(r.logger, level, msg, keyAndValues...)
 }

Original file line number	Diff line number	Diff line change
`@@ -123,6 +123,8 @@ type RuntimeService interface {`
`123`	`123`	`Status(ctx context.Context, verbose bool) (*runtimeapi.StatusResponse, error)`
`124`	`124`	`// RuntimeConfig returns the configuration information of the runtime.`
`125`	`125`	`RuntimeConfig(ctx context.Context) (*runtimeapi.RuntimeConfigResponse, error)`
	`126`	`+ // Close will shutdown the internal gRPC client connection.`
	`127`	`+ Close() error`
`126`	`128`	`}`
`127`	`129`
`128`	`130`	`// ImageManagerService interface should be implemented by a container image`
`@@ -139,4 +141,6 @@ type ImageManagerService interface {`
`139`	`141`	`RemoveImage(ctx context.Context, image *runtimeapi.ImageSpec) error`
`140`	`142`	`// ImageFsInfo returns information of the filesystem(s) used to store the read-only layers and the writeable layer.`
`141`	`143`	`ImageFsInfo(ctx context.Context) (*runtimeapi.ImageFsInfoResponse, error)`
	`144`	`+ // Close will shutdown the internal gRPC client connection.`
	`145`	`+ Close() error`
`142`	`146`	`}`