Add image load.

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

pkg/api/v1/api.proto

@@ -0,0 +1,30 @@
+// To regenerate api.pb.go run `make proto`hack/update-generated-runtime.sh
+syntax = 'proto3';
+
+package api.v1;
+
+import "github.com/gogo/protobuf/gogoproto/gogo.proto";
+
+option (gogoproto.goproto_stringer_all) = false;
+option (gogoproto.stringer_all) =  true;
+option (gogoproto.goproto_getters_all) = true;
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.sizer_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+option (gogoproto.goproto_unrecognized_all) = false;
+
+// CRIContainerdService defines non-CRI APIs for cri-containerd.
+service CRIContainerdService{
+    // LoadImage loads a image into containerd.
+    rpc LoadImage(LoadImageRequest) returns (LoadImageResponse) {}
+}
+
+message LoadImageRequest {
+    // FilePath is the absolute path of docker image tarball.
+    string FilePath = 1;
+}
+
+message LoadImageResponse {
+    // Images have been loaded.
+    repeated string Images = 1;
+}