1 //go:build windows 2 3 package main 4 5 import ( 6 "compress/gzip" 7 "context" 8 "io" 9 "os" 10 "path/filepath" 11 12 winio "github.com/Microsoft/go-winio" 13 "github.com/Microsoft/hcsshim/internal/appargs" 14 "github.com/Microsoft/hcsshim/pkg/ociwclayer" 15 "github.com/urfave/cli" 16 ) 17 18 var exportCommand = cli.Command{ 19 Name: "export", 20 Usage: "exports a layer to a tar file", 21 Flags: []cli.Flag{ 22 cli.StringSliceFlag{ 23 Name: "layer, l", 24 Usage: "paths to the read-only parent layers", 25 }, 26 cli.StringFlag{ 27 Name: "output, o", 28 Usage: "output layer tar (defaults to stdout)", 29 }, 30 cli.BoolFlag{ 31 Name: "gzip, z", 32 Usage: "compress output with gzip compression", 33 }, 34 }, 35 ArgsUsage: "<layer path>", 36 Before: appargs.Validate(appargs.NonEmptyString), 37 Action: func(cliContext *cli.Context) (err error) { 38 path, err := filepath.Abs(cliContext.Args().First()) 39 if err != nil { 40 return err 41 } 42 43 layers, err := normalizeLayers(cliContext.StringSlice("layer"), false) 44 if err != nil { 45 return err 46 } 47 48 err = winio.EnableProcessPrivileges([]string{winio.SeBackupPrivilege}) 49 if err != nil { 50 return err 51 } 52 53 fp := cliContext.String("output") 54 f := os.Stdout 55 if fp != "" { 56 f, err = os.Create(fp) 57 if err != nil { 58 return err 59 } 60 defer f.Close() 61 } 62 w := io.Writer(f) 63 if cliContext.Bool("gzip") { 64 w = gzip.NewWriter(w) 65 } 66 67 return ociwclayer.ExportLayerToTar(context.Background(), w, path, layers) 68 }, 69 } 70