use fu wei's suggeted interface pick for marshaling

Signed-off-by: Mike Brown <brownwm@us.ibm.com>

pkg/cri/server/instrumented_service.go

@@ -97,22 +97,19 @@ func (in *instrumentedAlphaService) RunPodSandbox(ctx context.Context, r *runtim
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.RunPodSandboxRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.RunPodSandboxResponse
 	v1res, err = in.c.RunPodSandbox(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.RunPodSandboxResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -121,8 +118,6 @@ func (in *instrumentedAlphaService) RunPodSandbox(ctx context.Context, r *runtim
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -155,22 +150,19 @@ func (in *instrumentedAlphaService) ListPodSandbox(ctx context.Context, r *runti
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ListPodSandboxRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ListPodSandboxResponse
 	v1res, err = in.c.ListPodSandbox(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ListPodSandboxResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -179,8 +171,6 @@ func (in *instrumentedAlphaService) ListPodSandbox(ctx context.Context, r *runti
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -213,22 +203,19 @@ func (in *instrumentedAlphaService) PodSandboxStatus(ctx context.Context, r *run
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.PodSandboxStatusRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.PodSandboxStatusResponse
 	v1res, err = in.c.PodSandboxStatus(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.PodSandboxStatusResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -237,8 +224,6 @@ func (in *instrumentedAlphaService) PodSandboxStatus(ctx context.Context, r *run
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -258,7 +243,7 @@ func (in *instrumentedService) StopPodSandbox(ctx context.Context, r *runtime.St
 	return res, errdefs.ToGRPC(err)
 }
 
-func (in *instrumentedAlphaService) StopPodSandbox(ctx context.Context, r *runtime_alpha.StopPodSandboxRequest) (_ *runtime_alpha.StopPodSandboxResponse, err error) {
+func (in *instrumentedAlphaService) StopPodSandbox(ctx context.Context, r *runtime_alpha.StopPodSandboxRequest) (res *runtime_alpha.StopPodSandboxResponse, err error) {
 	if err := in.checkInitialized(); err != nil {
 		return nil, err
 	}
@@ -270,24 +255,20 @@ func (in *instrumentedAlphaService) StopPodSandbox(ctx context.Context, r *runti
 			log.G(ctx).Infof("StopPodSandbox for %q returns successfully", r.GetPodSandboxId())
 		}
 	}()
-	var res *runtime_alpha.StopPodSandboxResponse
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.StopPodSandboxRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.StopPodSandboxResponse
 	v1res, err = in.c.StopPodSandbox(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.StopPodSandboxResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -296,8 +277,6 @@ func (in *instrumentedAlphaService) StopPodSandbox(ctx context.Context, r *runti
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -317,7 +296,7 @@ func (in *instrumentedService) RemovePodSandbox(ctx context.Context, r *runtime.
 	return res, errdefs.ToGRPC(err)
 }
 
-func (in *instrumentedAlphaService) RemovePodSandbox(ctx context.Context, r *runtime_alpha.RemovePodSandboxRequest) (_ *runtime_alpha.RemovePodSandboxResponse, err error) {
+func (in *instrumentedAlphaService) RemovePodSandbox(ctx context.Context, r *runtime_alpha.RemovePodSandboxRequest) (res *runtime_alpha.RemovePodSandboxResponse, err error) {
 	if err := in.checkInitialized(); err != nil {
 		return nil, err
 	}
@@ -329,24 +308,20 @@ func (in *instrumentedAlphaService) RemovePodSandbox(ctx context.Context, r *run
 			log.G(ctx).Infof("RemovePodSandbox %q returns successfully", r.GetPodSandboxId())
 		}
 	}()
-	var res *runtime_alpha.RemovePodSandboxResponse
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.RemovePodSandboxRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.RemovePodSandboxResponse
 	v1res, err = in.c.RemovePodSandbox(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.RemovePodSandboxResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -355,8 +330,6 @@ func (in *instrumentedAlphaService) RemovePodSandbox(ctx context.Context, r *run
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -389,22 +362,19 @@ func (in *instrumentedAlphaService) PortForward(ctx context.Context, r *runtime_
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.PortForwardRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.PortForwardResponse
 	v1res, err = in.c.PortForward(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.PortForwardResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -413,8 +383,6 @@ func (in *instrumentedAlphaService) PortForward(ctx context.Context, r *runtime_
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -453,22 +421,19 @@ func (in *instrumentedAlphaService) CreateContainer(ctx context.Context, r *runt
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.CreateContainerRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.CreateContainerResponse
 	v1res, err = in.c.CreateContainer(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.CreateContainerResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -478,8 +443,6 @@ func (in *instrumentedAlphaService) CreateContainer(ctx context.Context, r *runt
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -499,7 +462,7 @@ func (in *instrumentedService) StartContainer(ctx context.Context, r *runtime.St
 	return res, errdefs.ToGRPC(err)
 }
 
-func (in *instrumentedAlphaService) StartContainer(ctx context.Context, r *runtime_alpha.StartContainerRequest) (_ *runtime_alpha.StartContainerResponse, err error) {
+func (in *instrumentedAlphaService) StartContainer(ctx context.Context, r *runtime_alpha.StartContainerRequest) (res *runtime_alpha.StartContainerResponse, err error) {
 	if err := in.checkInitialized(); err != nil {
 		return nil, err
 	}
@@ -511,24 +474,20 @@ func (in *instrumentedAlphaService) StartContainer(ctx context.Context, r *runti
 			log.G(ctx).Infof("StartContainer for %q returns successfully", r.GetContainerId())
 		}
 	}()
-	var res *runtime_alpha.StartContainerResponse
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.StartContainerRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.StartContainerResponse
 	v1res, err = in.c.StartContainer(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.StartContainerResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -537,8 +496,6 @@ func (in *instrumentedAlphaService) StartContainer(ctx context.Context, r *runti
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -573,22 +530,19 @@ func (in *instrumentedAlphaService) ListContainers(ctx context.Context, r *runti
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ListContainersRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ListContainersResponse
 	v1res, err = in.c.ListContainers(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ListContainersResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -597,8 +551,6 @@ func (in *instrumentedAlphaService) ListContainers(ctx context.Context, r *runti
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -631,22 +583,19 @@ func (in *instrumentedAlphaService) ContainerStatus(ctx context.Context, r *runt
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ContainerStatusRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ContainerStatusResponse
 	v1res, err = in.c.ContainerStatus(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ContainerStatusResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -655,8 +604,6 @@ func (in *instrumentedAlphaService) ContainerStatus(ctx context.Context, r *runt
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -689,22 +636,19 @@ func (in *instrumentedAlphaService) StopContainer(ctx context.Context, r *runtim
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.StopContainerRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.StopContainerResponse
 	v1res, err = in.c.StopContainer(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.StopContainerResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -713,8 +657,6 @@ func (in *instrumentedAlphaService) StopContainer(ctx context.Context, r *runtim
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -747,22 +689,19 @@ func (in *instrumentedAlphaService) RemoveContainer(ctx context.Context, r *runt
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.RemoveContainerRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.RemoveContainerResponse
 	v1res, err = in.c.RemoveContainer(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.RemoveContainerResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -771,8 +710,6 @@ func (in *instrumentedAlphaService) RemoveContainer(ctx context.Context, r *runt
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -805,22 +742,19 @@ func (in *instrumentedAlphaService) ExecSync(ctx context.Context, r *runtime_alp
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ExecSyncRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ExecSyncResponse
 	v1res, err = in.c.ExecSync(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ExecSyncResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -829,8 +763,6 @@ func (in *instrumentedAlphaService) ExecSync(ctx context.Context, r *runtime_alp
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -865,22 +797,19 @@ func (in *instrumentedAlphaService) Exec(ctx context.Context, r *runtime_alpha.E
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ExecRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ExecResponse
 	v1res, err = in.c.Exec(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ExecResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -889,8 +818,6 @@ func (in *instrumentedAlphaService) Exec(ctx context.Context, r *runtime_alpha.E
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -923,22 +850,19 @@ func (in *instrumentedAlphaService) Attach(ctx context.Context, r *runtime_alpha
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.AttachRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.AttachResponse
 	v1res, err = in.c.Attach(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.AttachResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -947,8 +871,6 @@ func (in *instrumentedAlphaService) Attach(ctx context.Context, r *runtime_alpha
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -981,22 +903,19 @@ func (in *instrumentedAlphaService) UpdateContainerResources(ctx context.Context
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.UpdateContainerResourcesRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.UpdateContainerResourcesResponse
 	v1res, err = in.c.UpdateContainerResources(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.UpdateContainerResourcesResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1005,8 +924,6 @@ func (in *instrumentedAlphaService) UpdateContainerResources(ctx context.Context
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1041,22 +958,19 @@ func (in *instrumentedAlphaService) PullImage(ctx context.Context, r *runtime_al
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.PullImageRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.PullImageResponse
 	v1res, err = in.c.PullImage(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.PullImageResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1065,8 +979,6 @@ func (in *instrumentedAlphaService) PullImage(ctx context.Context, r *runtime_al
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1101,22 +1013,19 @@ func (in *instrumentedAlphaService) ListImages(ctx context.Context, r *runtime_a
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ListImagesRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ListImagesResponse
 	v1res, err = in.c.ListImages(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ListImagesResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1125,8 +1034,6 @@ func (in *instrumentedAlphaService) ListImages(ctx context.Context, r *runtime_a
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1161,22 +1068,19 @@ func (in *instrumentedAlphaService) ImageStatus(ctx context.Context, r *runtime_
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ImageStatusRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ImageStatusResponse
 	v1res, err = in.c.ImageStatus(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ImageStatusResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1185,8 +1089,6 @@ func (in *instrumentedAlphaService) ImageStatus(ctx context.Context, r *runtime_
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1206,7 +1108,7 @@ func (in *instrumentedService) RemoveImage(ctx context.Context, r *runtime.Remov
 	return res, errdefs.ToGRPC(err)
 }
 
-func (in *instrumentedAlphaService) RemoveImage(ctx context.Context, r *runtime_alpha.RemoveImageRequest) (_ *runtime_alpha.RemoveImageResponse, err error) {
+func (in *instrumentedAlphaService) RemoveImage(ctx context.Context, r *runtime_alpha.RemoveImageRequest) (res *runtime_alpha.RemoveImageResponse, err error) {
 	if err := in.checkInitialized(); err != nil {
 		return nil, err
 	}
@@ -1218,24 +1120,20 @@ func (in *instrumentedAlphaService) RemoveImage(ctx context.Context, r *runtime_
 			log.G(ctx).Infof("RemoveImage %q returns successfully", r.GetImage().GetImage())
 		}
 	}()
-	var res *runtime_alpha.RemoveImageResponse
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.RemoveImageRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.RemoveImageResponse
 	v1res, err = in.c.RemoveImage(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.RemoveImageResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1244,8 +1142,6 @@ func (in *instrumentedAlphaService) RemoveImage(ctx context.Context, r *runtime_
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1278,22 +1174,19 @@ func (in *instrumentedAlphaService) ImageFsInfo(ctx context.Context, r *runtime_
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ImageFsInfoRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ImageFsInfoResponse
 	v1res, err = in.c.ImageFsInfo(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ImageFsInfoResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1302,8 +1195,6 @@ func (in *instrumentedAlphaService) ImageFsInfo(ctx context.Context, r *runtime_
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1336,22 +1227,19 @@ func (in *instrumentedAlphaService) ContainerStats(ctx context.Context, r *runti
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ContainerStatsRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ContainerStatsResponse
 	v1res, err = in.c.ContainerStats(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ContainerStatsResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1360,8 +1248,6 @@ func (in *instrumentedAlphaService) ContainerStats(ctx context.Context, r *runti
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1394,22 +1280,19 @@ func (in *instrumentedAlphaService) ListContainerStats(ctx context.Context, r *r
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.ListContainerStatsRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.ListContainerStatsResponse
 	v1res, err = in.c.ListContainerStats(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.ListContainerStatsResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1418,8 +1301,6 @@ func (in *instrumentedAlphaService) ListContainerStats(ctx context.Context, r *r
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1452,22 +1333,19 @@ func (in *instrumentedAlphaService) Status(ctx context.Context, r *runtime_alpha
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.StatusRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.StatusResponse
 	v1res, err = in.c.Status(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.StatusResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1476,8 +1354,6 @@ func (in *instrumentedAlphaService) Status(ctx context.Context, r *runtime_alpha
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1542,22 +1418,19 @@ func (in *instrumentedAlphaService) UpdateRuntimeConfig(ctx context.Context, r *
 		}
 	}()
 	// converts request and response for earlier CRI version to call and get response from the current version
-	p, err := r.Marshal()
-	if err == nil {
 	var v1r runtime.UpdateRuntimeConfigRequest
-		if err = v1r.Unmarshal(p); err == nil {
+	if err := alphaReqToV1Req(r, &v1r); err != nil {
+		return nil, errdefs.ToGRPC(err)
+	}
 	var v1res *runtime.UpdateRuntimeConfigResponse
 	v1res, err = in.c.UpdateRuntimeConfig(ctrdutil.WithNamespace(ctx), &v1r)
 	if v1res != nil {
-				p, perr := v1res.Marshal()
-				if perr == nil {
 		resp := &runtime_alpha.UpdateRuntimeConfigResponse{}
-					if perr = resp.Unmarshal(p); perr == nil {
+		perr := v1RespToAlphaResp(v1res, resp)
+		if perr == nil {
 			res = resp
-					}
+		} else {
-				}
 			// actual error has precidence on error returned vs parse error issues
-				if perr != nil {
 			if err == nil {
 				err = perr
 			} else {
@@ -1566,8 +1439,6 @@ func (in *instrumentedAlphaService) UpdateRuntimeConfig(ctx context.Context, r *
 			}
 		}
 	}
-		}
-	}
 	return res, errdefs.ToGRPC(err)
 }
 
@@ -1628,3 +1499,33 @@ func (in *instrumentedAlphaService) ReopenContainerLog(ctx context.Context, r *r
 	}
 	return res, errdefs.ToGRPC(err)
 }
+
+func alphaReqToV1Req(
+	alphar interface{ Marshal() ([]byte, error) },
+	v1r interface{ Unmarshal(_ []byte) error },
+) error {
+	p, err := alphar.Marshal()
+	if err != nil {
+		return err
+	}
+
+	if err = v1r.Unmarshal(p); err != nil {
+		return err
+	}
+	return nil
+}
+
+func v1RespToAlphaResp(
+	v1res interface{ Marshal() ([]byte, error) },
+	alphares interface{ Unmarshal(_ []byte) error },
+) error {
+	p, err := v1res.Marshal()
+	if err != nil {
+		return err
+	}
+
+	if err = alphares.Unmarshal(p); err != nil {
+		return err
+	}
+	return nil
+}