|
| 1 | +// Copyright 2020 Google LLC All Rights Reserved. |
| 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 crane |
| 16 | + |
| 17 | +import ( |
| 18 | + "errors" |
| 19 | + "fmt" |
| 20 | + |
| 21 | + "github.com/containerd/stargz-snapshotter/estargz" |
| 22 | + "github.com/google/go-containerregistry/pkg/logs" |
| 23 | + "github.com/google/go-containerregistry/pkg/name" |
| 24 | + v1 "github.com/google/go-containerregistry/pkg/v1" |
| 25 | + "github.com/google/go-containerregistry/pkg/v1/empty" |
| 26 | + "github.com/google/go-containerregistry/pkg/v1/mutate" |
| 27 | + "github.com/google/go-containerregistry/pkg/v1/remote" |
| 28 | + "github.com/google/go-containerregistry/pkg/v1/tarball" |
| 29 | + "github.com/google/go-containerregistry/pkg/v1/types" |
| 30 | +) |
| 31 | + |
| 32 | +// Optimize optimizes a remote image or index from src to dst. |
| 33 | +// THIS API IS EXPERIMENTAL AND SUBJECT TO CHANGE WITHOUT WARNING. |
| 34 | +func Optimize(src, dst string, prioritize []string, opt ...Option) error { |
| 35 | + o := makeOptions(opt...) |
| 36 | + srcRef, err := name.ParseReference(src, o.name...) |
| 37 | + if err != nil { |
| 38 | + return fmt.Errorf("parsing reference %q: %v", src, err) |
| 39 | + } |
| 40 | + |
| 41 | + dstRef, err := name.ParseReference(dst, o.name...) |
| 42 | + if err != nil { |
| 43 | + return fmt.Errorf("parsing reference for %q: %v", dst, err) |
| 44 | + } |
| 45 | + |
| 46 | + logs.Progress.Printf("Optimizing from %v to %v", srcRef, dstRef) |
| 47 | + desc, err := remote.Get(srcRef, o.remote...) |
| 48 | + if err != nil { |
| 49 | + return fmt.Errorf("fetching %q: %v", src, err) |
| 50 | + } |
| 51 | + |
| 52 | + switch desc.MediaType { |
| 53 | + case types.OCIImageIndex, types.DockerManifestList: |
| 54 | + // Handle indexes separately. |
| 55 | + if o.platform != nil { |
| 56 | + // If platform is explicitly set, don't optimize the whole index, just the appropriate image. |
| 57 | + if err := optimizeAndPushImage(desc, dstRef, prioritize, o); err != nil { |
| 58 | + return fmt.Errorf("failed to optimize image: %v", err) |
| 59 | + } |
| 60 | + } else { |
| 61 | + if err := optimizeAndPushIndex(desc, dstRef, prioritize, o); err != nil { |
| 62 | + return fmt.Errorf("failed to optimize index: %v", err) |
| 63 | + } |
| 64 | + } |
| 65 | + |
| 66 | + case types.DockerManifestSchema1, types.DockerManifestSchema1Signed: |
| 67 | + return errors.New("docker schema 1 images are not supported") |
| 68 | + |
| 69 | + default: |
| 70 | + // Assume anything else is an image, since some registries don't set mediaTypes properly. |
| 71 | + if err := optimizeAndPushImage(desc, dstRef, prioritize, o); err != nil { |
| 72 | + return fmt.Errorf("failed to optimize image: %v", err) |
| 73 | + } |
| 74 | + } |
| 75 | + |
| 76 | + return nil |
| 77 | +} |
| 78 | + |
| 79 | +func optimizeAndPushImage(desc *remote.Descriptor, dstRef name.Reference, prioritize []string, o options) error { |
| 80 | + img, err := desc.Image() |
| 81 | + if err != nil { |
| 82 | + return err |
| 83 | + } |
| 84 | + |
| 85 | + oimg, err := optimizeImage(img, prioritize) |
| 86 | + if err != nil { |
| 87 | + return err |
| 88 | + } |
| 89 | + |
| 90 | + return remote.Write(dstRef, oimg, o.remote...) |
| 91 | +} |
| 92 | + |
| 93 | +func optimizeImage(img v1.Image, prioritize []string) (v1.Image, error) { |
| 94 | + cfg, err := img.ConfigFile() |
| 95 | + if err != nil { |
| 96 | + return nil, err |
| 97 | + } |
| 98 | + ocfg := cfg.DeepCopy() |
| 99 | + ocfg.History = nil |
| 100 | + ocfg.RootFS.DiffIDs = nil |
| 101 | + |
| 102 | + oimg, err := mutate.ConfigFile(empty.Image, ocfg) |
| 103 | + if err != nil { |
| 104 | + return nil, err |
| 105 | + } |
| 106 | + |
| 107 | + layers, err := img.Layers() |
| 108 | + if err != nil { |
| 109 | + return nil, err |
| 110 | + } |
| 111 | + |
| 112 | + olayers := make([]mutate.Addendum, 0, len(layers)) |
| 113 | + for _, layer := range layers { |
| 114 | + olayer, err := tarball.LayerFromOpener(layer.Uncompressed, |
| 115 | + tarball.WithEstargz, |
| 116 | + tarball.WithEstargzOptions(estargz.WithPrioritizedFiles(prioritize))) |
| 117 | + if err != nil { |
| 118 | + return nil, err |
| 119 | + } |
| 120 | + |
| 121 | + olayers = append(olayers, mutate.Addendum{ |
| 122 | + Layer: olayer, |
| 123 | + MediaType: types.DockerLayer, |
| 124 | + }) |
| 125 | + } |
| 126 | + |
| 127 | + return mutate.Append(oimg, olayers...) |
| 128 | +} |
| 129 | + |
| 130 | +func optimizeAndPushIndex(desc *remote.Descriptor, dstRef name.Reference, prioritize []string, o options) error { |
| 131 | + idx, err := desc.ImageIndex() |
| 132 | + if err != nil { |
| 133 | + return err |
| 134 | + } |
| 135 | + |
| 136 | + oidx, err := optimizeIndex(idx, prioritize) |
| 137 | + if err != nil { |
| 138 | + return err |
| 139 | + } |
| 140 | + |
| 141 | + return remote.WriteIndex(dstRef, oidx, o.remote...) |
| 142 | +} |
| 143 | + |
| 144 | +func optimizeIndex(idx v1.ImageIndex, prioritize []string) (v1.ImageIndex, error) { |
| 145 | + im, err := idx.IndexManifest() |
| 146 | + if err != nil { |
| 147 | + return nil, err |
| 148 | + } |
| 149 | + |
| 150 | + // Build an image for each child from the base and append it to a new index to produce the result. |
| 151 | + adds := make([]mutate.IndexAddendum, 0, len(im.Manifests)) |
| 152 | + for _, desc := range im.Manifests { |
| 153 | + img, err := idx.Image(desc.Digest) |
| 154 | + if err != nil { |
| 155 | + return nil, err |
| 156 | + } |
| 157 | + |
| 158 | + oimg, err := optimizeImage(img, prioritize) |
| 159 | + if err != nil { |
| 160 | + return nil, err |
| 161 | + } |
| 162 | + adds = append(adds, mutate.IndexAddendum{ |
| 163 | + Add: oimg, |
| 164 | + Descriptor: v1.Descriptor{ |
| 165 | + URLs: desc.URLs, |
| 166 | + MediaType: desc.MediaType, |
| 167 | + Annotations: desc.Annotations, |
| 168 | + Platform: desc.Platform, |
| 169 | + }, |
| 170 | + }) |
| 171 | + } |
| 172 | + |
| 173 | + idxType, err := idx.MediaType() |
| 174 | + if err != nil { |
| 175 | + return nil, err |
| 176 | + } |
| 177 | + |
| 178 | + return mutate.IndexMediaType(mutate.AppendManifests(empty.Index, adds...), idxType), nil |
| 179 | +} |
0 commit comments