1 //go:build windows 2 3 package main 4 5 import ( 6 "bufio" 7 "compress/gzip" 8 "context" 9 "io" 10 "os" 11 "path/filepath" 12 13 "github.com/Microsoft/go-winio" 14 "github.com/Microsoft/hcsshim/internal/appargs" 15 "github.com/Microsoft/hcsshim/pkg/ociwclayer" 16 "github.com/urfave/cli" 17 ) 18 19 var importCommand = cli.Command{ 20 Name: "import", 21 Usage: "imports a layer from a tar file", 22 Flags: []cli.Flag{ 23 cli.StringSliceFlag{ 24 Name: "layer, l", 25 Usage: "paths to the read-only parent layers", 26 }, 27 cli.StringFlag{ 28 Name: "input, i", 29 Usage: "input layer tar (defaults to stdin)", 30 }, 31 }, 32 ArgsUsage: "<layer path>", 33 Before: appargs.Validate(appargs.NonEmptyString), 34 Action: func(cliContext *cli.Context) (err error) { 35 path, err := filepath.Abs(cliContext.Args().First()) 36 if err != nil { 37 return err 38 } 39 40 layers, err := normalizeLayers(cliContext.StringSlice("layer"), false) 41 if err != nil { 42 return err 43 } 44 45 fp := cliContext.String("input") 46 f := os.Stdin 47 if fp != "" { 48 f, err = os.Open(fp) 49 if err != nil { 50 return err 51 } 52 defer f.Close() 53 } 54 r, err := addDecompressor(f) 55 if err != nil { 56 return err 57 } 58 err = winio.EnableProcessPrivileges([]string{winio.SeBackupPrivilege, winio.SeRestorePrivilege}) 59 if err != nil { 60 return err 61 } 62 _, err = ociwclayer.ImportLayerFromTar(context.Background(), r, path, layers) 63 return err 64 }, 65 } 66 67 func addDecompressor(r io.Reader) (io.Reader, error) { 68 b := bufio.NewReader(r) 69 hdr, err := b.Peek(3) 70 if err != nil { 71 return nil, err 72 } 73 if hdr[0] == 0x1f && hdr[1] == 0x8b && hdr[2] == 8 { 74 return gzip.NewReader(b) 75 } 76 return b, nil 77 } 78