Serge Bazanski | be538db | 2020-11-12 00:22:42 +0100 | [diff] [blame] | 1 | // Copyright 2017 The kubecfg authors |
| 2 | // |
| 3 | // |
| 4 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | // you may not use this file except in compliance with the License. |
| 6 | // You may obtain a copy of the License at |
| 7 | // |
| 8 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | // |
| 10 | // Unless required by applicable law or agreed to in writing, software |
| 11 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | // See the License for the specific language governing permissions and |
| 14 | // limitations under the License. |
| 15 | |
| 16 | package utils |
| 17 | |
| 18 | import ( |
| 19 | "bytes" |
| 20 | "context" |
| 21 | "fmt" |
| 22 | |
| 23 | "github.com/genuinetools/reg/registry" |
| 24 | "github.com/genuinetools/reg/repoutils" |
| 25 | ) |
| 26 | |
| 27 | const defaultRegistry = "registry-1.docker.io" |
| 28 | |
| 29 | // ImageName represents the parts of a docker image name |
| 30 | type ImageName struct { |
| 31 | // eg: "myregistryhost:5000/fedora/httpd:version1.0" |
| 32 | Registry string // "myregistryhost:5000" |
| 33 | Repository string // "fedora" |
| 34 | Name string // "httpd" |
| 35 | Tag string // "version1.0" |
| 36 | Digest string |
| 37 | } |
| 38 | |
| 39 | // String implements the Stringer interface |
| 40 | func (n ImageName) String() string { |
| 41 | buf := bytes.Buffer{} |
| 42 | if n.Registry != "" { |
| 43 | buf.WriteString(n.Registry) |
| 44 | buf.WriteString("/") |
| 45 | } |
| 46 | if n.Repository != "" { |
| 47 | buf.WriteString(n.Repository) |
| 48 | buf.WriteString("/") |
| 49 | } |
| 50 | buf.WriteString(n.Name) |
| 51 | if n.Digest != "" { |
| 52 | buf.WriteString("@") |
| 53 | buf.WriteString(n.Digest) |
| 54 | } else { |
| 55 | buf.WriteString(":") |
| 56 | buf.WriteString(n.Tag) |
| 57 | } |
| 58 | return buf.String() |
| 59 | } |
| 60 | |
| 61 | // RegistryRepoName returns the "repository" as used in the registry URL |
| 62 | func (n ImageName) RegistryRepoName() string { |
| 63 | repo := n.Repository |
| 64 | if repo == "" { |
| 65 | repo = "library" |
| 66 | } |
| 67 | return fmt.Sprintf("%s/%s", repo, n.Name) |
| 68 | } |
| 69 | |
| 70 | // RegistryURL returns the deduced base URL of the registry for this image |
| 71 | func (n ImageName) RegistryURL() string { |
| 72 | reg := n.Registry |
| 73 | if reg == "" { |
| 74 | reg = defaultRegistry |
| 75 | } |
| 76 | return fmt.Sprintf("https://%s", reg) |
| 77 | } |
| 78 | |
| 79 | // ParseImageName parses a docker image into an ImageName struct. |
| 80 | func ParseImageName(image string) (ImageName, error) { |
| 81 | ret := ImageName{} |
| 82 | |
| 83 | img, err := registry.ParseImage(image) |
| 84 | if err != nil { |
| 85 | return ret, err |
| 86 | } |
| 87 | |
| 88 | ret.Registry = img.Domain |
| 89 | ret.Name = img.Path |
| 90 | ret.Digest = img.Digest.String() |
| 91 | ret.Tag = img.Tag |
| 92 | |
| 93 | return ret, nil |
| 94 | } |
| 95 | |
| 96 | // Resolver is able to resolve docker image names into more specific forms |
| 97 | type Resolver interface { |
| 98 | Resolve(image *ImageName) error |
| 99 | } |
| 100 | |
| 101 | // NewIdentityResolver returns a resolver that does only trivial |
| 102 | // :latest canonicalisation |
| 103 | func NewIdentityResolver() Resolver { |
| 104 | return identityResolver{} |
| 105 | } |
| 106 | |
| 107 | type identityResolver struct{} |
| 108 | |
| 109 | func (r identityResolver) Resolve(image *ImageName) error { |
| 110 | return nil |
| 111 | } |
| 112 | |
| 113 | // NewRegistryResolver returns a resolver that looks up a docker |
| 114 | // registry to resolve digests |
| 115 | func NewRegistryResolver(opt registry.Opt) Resolver { |
| 116 | return ®istryResolver{ |
| 117 | opt: opt, |
| 118 | cache: make(map[string]string), |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | type registryResolver struct { |
| 123 | opt registry.Opt |
| 124 | cache map[string]string |
| 125 | } |
| 126 | |
| 127 | func (r *registryResolver) Resolve(n *ImageName) error { |
| 128 | // TODO: get context from caller. |
| 129 | ctx := context.Background() |
| 130 | |
| 131 | if n.Digest != "" { |
| 132 | // Already has explicit digest |
| 133 | return nil |
| 134 | } |
| 135 | |
| 136 | if digest, ok := r.cache[n.String()]; ok { |
| 137 | n.Digest = digest |
| 138 | return nil |
| 139 | } |
| 140 | |
| 141 | img, err := registry.ParseImage(n.String()) |
| 142 | if err != nil { |
| 143 | return fmt.Errorf("unable to parse image name: %v", err) |
| 144 | } |
| 145 | |
| 146 | auth, err := repoutils.GetAuthConfig("", "", img.Domain) |
| 147 | if err != nil { |
| 148 | return fmt.Errorf("unable to get auth config for registry: %v", err) |
| 149 | } |
| 150 | |
| 151 | c, err := registry.New(ctx, auth, r.opt) |
| 152 | if err != nil { |
| 153 | return fmt.Errorf("unable to create registry client: %v", err) |
| 154 | } |
| 155 | |
| 156 | digest, err := c.Digest(ctx, img) |
| 157 | if err != nil { |
| 158 | return fmt.Errorf("unable to get digest from the registry: %v", err) |
| 159 | } |
| 160 | |
| 161 | n.Digest = digest.String() |
| 162 | r.cache[n.String()] = n.Digest |
| 163 | |
| 164 | return nil |
| 165 | } |