github.com/alibaba/sealer@v0.8.6-0.20220430115802-37a2bdaa8173/pkg/image/save/utils.go (about)

     1  // Copyright © 2021 Alibaba Group Holding Ltd.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package save
    16  
    17  import (
    18  	"fmt"
    19  	"strings"
    20  )
    21  
    22  //this package contains some utils to handle docker image name
    23  const (
    24  	legacyDefaultDomain = "index.docker.io"
    25  	defaultDomain       = "docker.io"
    26  	officialRepoName    = "library"
    27  	defaultTag          = "latest"
    28  )
    29  
    30  // docker image name struct
    31  type Named struct {
    32  	domain string //eg. docker.io
    33  	repo   string //eg. library/ubuntu
    34  	tag    string //eg. latest
    35  }
    36  
    37  func (n Named) FullName() string {
    38  	return n.domain + "/" + n.repo + ":" + n.tag
    39  }
    40  
    41  func (n Named) Domain() string {
    42  	return n.domain
    43  }
    44  
    45  func (n Named) Repo() string {
    46  	return n.repo
    47  }
    48  
    49  func (n Named) Tag() string {
    50  	return n.tag
    51  }
    52  
    53  func splitDockerDomain(name string, registry string) (domain, remainder string) {
    54  	i := strings.IndexRune(name, '/')
    55  	if i == -1 || (!strings.ContainsAny(name[:i], ".:") && name[:i] != "localhost" && strings.ToLower(name[:i]) == name[:i]) {
    56  		if registry != "" {
    57  			domain, remainder = registry, name
    58  		} else {
    59  			domain, remainder = defaultDomain, name
    60  		}
    61  	} else {
    62  		domain, remainder = name[:i], name[i+1:]
    63  	}
    64  
    65  	if domain == legacyDefaultDomain {
    66  		domain = defaultDomain
    67  	}
    68  	if domain == defaultDomain && !strings.ContainsRune(remainder, '/') {
    69  		remainder = officialRepoName + "/" + remainder
    70  	}
    71  	return
    72  }
    73  
    74  func ParseNormalizedNamed(s string, registry string) (Named, error) {
    75  	domain, remainder := splitDockerDomain(s, registry)
    76  	var remoteName, tag string
    77  	if tagSep := strings.IndexRune(remainder, ':'); tagSep > -1 {
    78  		tag = remainder[tagSep+1:]
    79  		remoteName = remainder[:tagSep]
    80  	} else {
    81  		tag = defaultTag
    82  		remoteName = remainder
    83  	}
    84  	if strings.ToLower(remoteName) != remoteName {
    85  		return Named{}, fmt.Errorf("invalid reference format: repository name (%s) must be lowercase", remoteName)
    86  	}
    87  
    88  	named := Named{
    89  		domain: domain,
    90  		repo:   remoteName,
    91  		tag:    tag,
    92  	}
    93  	return named, nil
    94  }