1/*
2Copyright 2015 The Kubernetes Authors.
3
4Licensed under the Apache License, Version 2.0 (the "License");
5you may not use this file except in compliance with the License.
6You may obtain a copy of the License at
7
8    http://www.apache.org/licenses/LICENSE-2.0
9
10Unless required by applicable law or agreed to in writing, software
11distributed under the License is distributed on an "AS IS" BASIS,
12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13See the License for the specific language governing permissions and
14limitations under the License.
15*/
16
17package parsers
18
19import (
20	"fmt"
21
22	dockerref "github.com/docker/distribution/reference"
23)
24
25const (
26	DefaultImageTag = "latest"
27)
28
29// ParseImageName parses a docker image string into three parts: repo, tag and digest.
30// If both tag and digest are empty, a default image tag will be returned.
31func ParseImageName(image string) (string, string, string, error) {
32	named, err := dockerref.ParseNamed(image)
33	if err != nil {
34		return "", "", "", fmt.Errorf("couldn't parse image name: %v", err)
35	}
36
37	repoToPull := named.Name()
38	var tag, digest string
39
40	tagged, ok := named.(dockerref.Tagged)
41	if ok {
42		tag = tagged.Tag()
43	}
44
45	digested, ok := named.(dockerref.Digested)
46	if ok {
47		digest = digested.Digest().String()
48	}
49	// If no tag was specified, use the default "latest".
50	if len(tag) == 0 && len(digest) == 0 {
51		tag = DefaultImageTag
52	}
53	return repoToPull, tag, digest, nil
54}
55