Refactor pkg packages

Signed-off-by: Maksym Pavlenko <pavlenko.maksym@gmail.com>

pkg/cri/util/deep_copy.go

@@ -0,0 +1,42 @@
+/*
+   Copyright The containerd 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"
+
+	"github.com/pkg/errors"
+)
+
+// DeepCopy makes a deep copy from src into dst.
+func DeepCopy(dst interface{}, src interface{}) error {
+	if dst == nil {
+		return errors.New("dst cannot be nil")
+	}
+	if src == nil {
+		return errors.New("src cannot be nil")
+	}
+	bytes, err := json.Marshal(src)
+	if err != nil {
+		return errors.Wrap(err, "unable to marshal src")
+	}
+	err = json.Unmarshal(bytes, dst)
+	if err != nil {
+		return errors.Wrap(err, "unable to unmarshal into dst")
+	}
+	return nil
+}