Add our own DeepCopy.

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

pkg/server/container_update_resources.go

@@ -28,10 +28,10 @@ import (
 	runtimespec "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/opencontainers/runtime-tools/generate"
 	"golang.org/x/net/context"
-	"k8s.io/apimachinery/pkg/conversion"
 	"k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
 
 	containerstore "github.com/kubernetes-incubator/cri-containerd/pkg/store/container"
+	"github.com/kubernetes-incubator/cri-containerd/pkg/util"
 )
 
 // UpdateContainerResources updates ContainerConfig of the container.
@@ -129,11 +129,11 @@ func updateContainerSpec(ctx context.Context, cntr containerd.Container, spec *r
 // updateOCILinuxResource updates container resource limit.
 func updateOCILinuxResource(spec *runtimespec.Spec, new *runtime.LinuxContainerResources) (*runtimespec.Spec, error) {
 	// Copy to make sure old spec is not changed.
-	cloned, err := conversion.NewCloner().DeepCopy(spec)
+	var cloned runtimespec.Spec
-	if err != nil {
+	if err := util.DeepCopy(&cloned, spec); err != nil {
 		return nil, fmt.Errorf("failed to deep copy: %v", err)
 	}
-	g := generate.NewFromSpec(cloned.(*runtimespec.Spec))
+	g := generate.NewFromSpec(&cloned)
 
 	if new.GetCpuPeriod() != 0 {
 		g.SetLinuxResourcesCPUPeriod(uint64(new.GetCpuPeriod()))

pkg/util/deep_copy.go

@@ -0,0 +1,41 @@
+/*
+Copyright 2017 The Kubernetes 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 util
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// DeepCopy makes a deep copy from src into dst.
+func DeepCopy(dst interface{}, src interface{}) error {
+	if dst == nil {
+		return fmt.Errorf("dst cannot be nil")
+	}
+	if src == nil {
+		return fmt.Errorf("src cannot be nil")
+	}
+	bytes, err := json.Marshal(src)
+	if err != nil {
+		return fmt.Errorf("unable to marshal src: %s", err)
+	}
+	err = json.Unmarshal(bytes, dst)
+	if err != nil {
+		return fmt.Errorf("unable to unmarshal into dst: %s", err)
+	}
+	return nil
+}

pkg/util/deep_copy_test.go

@@ -0,0 +1,63 @@
+/*
+Copyright 2017 The Kubernetes 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 util
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type A struct {
+	String  string
+	Int     int
+	Strings []string
+	Ints    map[string]int
+	As      map[string]*A
+}
+
+func TestCopy(t *testing.T) {
+	src := &A{
+		String:  "Hello World",
+		Int:     5,
+		Strings: []string{"A", "B"},
+		Ints:    map[string]int{"A": 1, "B": 2, "C": 4},
+		As: map[string]*A{
+			"One": {String: "2"},
+			"Two": {String: "3"},
+		},
+	}
+	dst := &A{
+		Strings: []string{"C"},
+		Ints:    map[string]int{"B": 3, "C": 4},
+		As:      map[string]*A{"One": {String: "1", Int: 5}},
+	}
+	expected := &A{
+		String:  "Hello World",
+		Int:     5,
+		Strings: []string{"A", "B"},
+		Ints:    map[string]int{"A": 1, "B": 2, "C": 4},
+		As: map[string]*A{
+			"One": {String: "2"},
+			"Two": {String: "3"},
+		},
+	}
+	assert.NotEqual(t, expected, dst)
+	err := DeepCopy(dst, src)
+	assert.NoError(t, err)
+	assert.Equal(t, expected, dst)
+}