1/* 2 Copyright The containerd Authors. 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 17package images 18 19import ( 20 "fmt" 21 22 "github.com/containerd/containerd" 23 "github.com/containerd/containerd/cmd/ctr/commands" 24 "github.com/containerd/containerd/cmd/ctr/commands/content" 25 "github.com/containerd/containerd/images" 26 "github.com/containerd/containerd/log" 27 "github.com/containerd/containerd/platforms" 28 "github.com/opencontainers/image-spec/identity" 29 ocispec "github.com/opencontainers/image-spec/specs-go/v1" 30 "github.com/pkg/errors" 31 "github.com/urfave/cli" 32) 33 34var pullCommand = cli.Command{ 35 Name: "pull", 36 Usage: "pull an image from a remote", 37 ArgsUsage: "[flags] <ref>", 38 Description: `Fetch and prepare an image for use in containerd. 39 40After pulling an image, it should be ready to use the same reference in a run 41command. As part of this process, we do the following: 42 431. Fetch all resources into containerd. 442. Prepare the snapshot filesystem with the pulled resources. 453. Register metadata for the image. 46`, 47 Flags: append(append(commands.RegistryFlags, append(commands.SnapshotterFlags, commands.LabelFlag)...), 48 cli.StringSliceFlag{ 49 Name: "platform", 50 Usage: "Pull content from a specific platform", 51 Value: &cli.StringSlice{}, 52 }, 53 cli.BoolFlag{ 54 Name: "all-platforms", 55 Usage: "pull content and metadata from all platforms", 56 }, 57 cli.BoolFlag{ 58 Name: "all-metadata", 59 Usage: "Pull metadata for all platforms", 60 }, 61 cli.BoolFlag{ 62 Name: "print-chainid", 63 Usage: "Print the resulting image's chain ID", 64 }, 65 ), 66 Action: func(context *cli.Context) error { 67 var ( 68 ref = context.Args().First() 69 ) 70 if ref == "" { 71 return fmt.Errorf("please provide an image reference to pull") 72 } 73 74 client, ctx, cancel, err := commands.NewClient(context) 75 if err != nil { 76 return err 77 } 78 defer cancel() 79 80 ctx, done, err := client.WithLease(ctx) 81 if err != nil { 82 return err 83 } 84 defer done(ctx) 85 86 config, err := content.NewFetchConfig(ctx, context) 87 if err != nil { 88 return err 89 } 90 91 img, err := content.Fetch(ctx, client, ref, config) 92 if err != nil { 93 return err 94 } 95 96 log.G(ctx).WithField("image", ref).Debug("unpacking") 97 98 // TODO: Show unpack status 99 100 var p []ocispec.Platform 101 if context.Bool("all-platforms") { 102 p, err = images.Platforms(ctx, client.ContentStore(), img.Target) 103 if err != nil { 104 return errors.Wrap(err, "unable to resolve image platforms") 105 } 106 } else { 107 for _, s := range context.StringSlice("platform") { 108 ps, err := platforms.Parse(s) 109 if err != nil { 110 return errors.Wrapf(err, "unable to parse platform %s", s) 111 } 112 p = append(p, ps) 113 } 114 } 115 if len(p) == 0 { 116 p = append(p, platforms.DefaultSpec()) 117 } 118 119 for _, platform := range p { 120 fmt.Printf("unpacking %s %s...\n", platforms.Format(platform), img.Target.Digest) 121 i := containerd.NewImageWithPlatform(client, img, platforms.Only(platform)) 122 err = i.Unpack(ctx, context.String("snapshotter")) 123 if err != nil { 124 return err 125 } 126 if context.Bool("print-chainid") { 127 diffIDs, err := i.RootFS(ctx) 128 if err != nil { 129 return err 130 } 131 chainID := identity.ChainID(diffIDs).String() 132 fmt.Printf("image chain ID: %s\n", chainID) 133 } 134 } 135 136 fmt.Println("done") 137 return nil 138 }, 139} 140