|
| 1 | +package assets |
| 2 | + |
| 3 | +import ( |
| 4 | + "archive/tar" |
| 5 | + "compress/gzip" |
| 6 | + "context" |
| 7 | + "io" |
| 8 | + "net/http" |
| 9 | + "os" |
| 10 | + "path/filepath" |
| 11 | + "strings" |
| 12 | + |
| 13 | + "github.com/pkg/errors" |
| 14 | + "oras.land/oras-go/v2" |
| 15 | + "oras.land/oras-go/v2/content/file" |
| 16 | + "oras.land/oras-go/v2/registry" |
| 17 | + "oras.land/oras-go/v2/registry/remote" |
| 18 | + "oras.land/oras-go/v2/registry/remote/auth" |
| 19 | +) |
| 20 | + |
| 21 | +const ( |
| 22 | + defaultArchiveName = "app-assets.tgz" |
| 23 | +) |
| 24 | + |
| 25 | +// DownloadFromImage pulls assets from an OCI image and unpacks them into outputDir. |
| 26 | +func DownloadFromImage(ctx context.Context, imageRef, outputDir string) error { |
| 27 | + if imageRef == "" { |
| 28 | + return errors.New("image reference is required") |
| 29 | + } |
| 30 | + if outputDir == "" { |
| 31 | + return errors.New("assets output directory is required") |
| 32 | + } |
| 33 | + |
| 34 | + if err := os.MkdirAll(outputDir, 0o755); err != nil { |
| 35 | + return errors.Wrapf(err, "failed to create assets output directory %s", outputDir) |
| 36 | + } |
| 37 | + |
| 38 | + tempDir, err := os.MkdirTemp("", "runme-agent-assets-*") |
| 39 | + if err != nil { |
| 40 | + return errors.Wrap(err, "failed to create temporary assets directory") |
| 41 | + } |
| 42 | + defer func() { |
| 43 | + _ = os.RemoveAll(tempDir) |
| 44 | + }() |
| 45 | + |
| 46 | + if err := pullImage(ctx, imageRef, tempDir); err != nil { |
| 47 | + return err |
| 48 | + } |
| 49 | + |
| 50 | + archivePath := filepath.Join(tempDir, defaultArchiveName) |
| 51 | + if _, err := os.Stat(archivePath); err != nil { |
| 52 | + return errors.Wrapf(err, "expected assets archive not found: %s", archivePath) |
| 53 | + } |
| 54 | + |
| 55 | + if err := removeIndexFiles(outputDir); err != nil { |
| 56 | + return err |
| 57 | + } |
| 58 | + if err := extractTarGz(archivePath, outputDir); err != nil { |
| 59 | + return errors.Wrapf(err, "failed to extract assets archive %s", archivePath) |
| 60 | + } |
| 61 | + |
| 62 | + return nil |
| 63 | +} |
| 64 | + |
| 65 | +func removeIndexFiles(outputDir string) error { |
| 66 | + matches, err := filepath.Glob(filepath.Join(outputDir, "index.*")) |
| 67 | + if err != nil { |
| 68 | + return errors.Wrapf(err, "failed to glob index files in %s", outputDir) |
| 69 | + } |
| 70 | + for _, match := range matches { |
| 71 | + if err := os.RemoveAll(match); err != nil { |
| 72 | + return errors.Wrapf(err, "failed to remove %s", match) |
| 73 | + } |
| 74 | + } |
| 75 | + return nil |
| 76 | +} |
| 77 | + |
| 78 | +func pullImage(ctx context.Context, imageRef, outputDir string) error { |
| 79 | + ref, err := registry.ParseReference(imageRef) |
| 80 | + if err != nil { |
| 81 | + return errors.Wrapf(err, "invalid image reference %q", imageRef) |
| 82 | + } |
| 83 | + |
| 84 | + repo, err := remote.NewRepository(ref.Registry + "/" + ref.Repository) |
| 85 | + if err != nil { |
| 86 | + return errors.Wrapf(err, "failed to create repository for %q", imageRef) |
| 87 | + } |
| 88 | + |
| 89 | + repo.Client = &auth.Client{ |
| 90 | + Client: http.DefaultClient, |
| 91 | + Cache: auth.NewCache(), |
| 92 | + } |
| 93 | + |
| 94 | + if ref.Reference == "" { |
| 95 | + ref.Reference = "latest" |
| 96 | + } |
| 97 | + |
| 98 | + store, err := file.New(outputDir) |
| 99 | + if err != nil { |
| 100 | + return errors.Wrapf(err, "failed to create output file store %s", outputDir) |
| 101 | + } |
| 102 | + defer store.Close() |
| 103 | + |
| 104 | + if _, err := oras.Copy(ctx, repo, ref.Reference, store, "", oras.DefaultCopyOptions); err != nil { |
| 105 | + return errors.Wrapf(err, "failed to pull image %s", imageRef) |
| 106 | + } |
| 107 | + |
| 108 | + return nil |
| 109 | +} |
| 110 | + |
| 111 | +func extractTarGz(archivePath, destDir string) error { |
| 112 | + fileHandle, err := os.Open(archivePath) |
| 113 | + if err != nil { |
| 114 | + return errors.Wrapf(err, "failed to open archive %s", archivePath) |
| 115 | + } |
| 116 | + defer fileHandle.Close() |
| 117 | + |
| 118 | + gzipReader, err := gzip.NewReader(fileHandle) |
| 119 | + if err != nil { |
| 120 | + return errors.Wrap(err, "failed to create gzip reader") |
| 121 | + } |
| 122 | + defer gzipReader.Close() |
| 123 | + |
| 124 | + tarReader := tar.NewReader(gzipReader) |
| 125 | + destDirClean := filepath.Clean(destDir) |
| 126 | + if !strings.HasSuffix(destDirClean, string(os.PathSeparator)) { |
| 127 | + destDirClean += string(os.PathSeparator) |
| 128 | + } |
| 129 | + |
| 130 | + for { |
| 131 | + header, err := tarReader.Next() |
| 132 | + if err == io.EOF { |
| 133 | + break |
| 134 | + } |
| 135 | + if err != nil { |
| 136 | + return errors.Wrap(err, "failed to read tar entry") |
| 137 | + } |
| 138 | + |
| 139 | + if header == nil { |
| 140 | + continue |
| 141 | + } |
| 142 | + |
| 143 | + targetPath := filepath.Join(destDir, header.Name) |
| 144 | + cleanTarget := filepath.Clean(targetPath) |
| 145 | + if !strings.HasPrefix(cleanTarget, destDirClean) { |
| 146 | + return errors.Errorf("invalid tar entry path: %s", header.Name) |
| 147 | + } |
| 148 | + |
| 149 | + switch header.Typeflag { |
| 150 | + case tar.TypeDir: |
| 151 | + if err := os.MkdirAll(cleanTarget, os.FileMode(header.Mode)); err != nil { |
| 152 | + return errors.Wrapf(err, "failed to create directory %s", cleanTarget) |
| 153 | + } |
| 154 | + case tar.TypeReg, tar.TypeRegA: |
| 155 | + if err := os.MkdirAll(filepath.Dir(cleanTarget), 0o755); err != nil { |
| 156 | + return errors.Wrapf(err, "failed to create parent directory for %s", cleanTarget) |
| 157 | + } |
| 158 | + outFile, err := os.OpenFile(cleanTarget, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, os.FileMode(header.Mode)) |
| 159 | + if err != nil { |
| 160 | + return errors.Wrapf(err, "failed to create file %s", cleanTarget) |
| 161 | + } |
| 162 | + if _, err := io.Copy(outFile, tarReader); err != nil { |
| 163 | + _ = outFile.Close() |
| 164 | + return errors.Wrapf(err, "failed to write file %s", cleanTarget) |
| 165 | + } |
| 166 | + if err := outFile.Close(); err != nil { |
| 167 | + return errors.Wrapf(err, "failed to close file %s", cleanTarget) |
| 168 | + } |
| 169 | + default: |
| 170 | + return errors.Errorf("unsupported tar entry type %v for %s", header.Typeflag, header.Name) |
| 171 | + } |
| 172 | + } |
| 173 | + |
| 174 | + return nil |
| 175 | +} |
0 commit comments