wip xz/commander

internal/cmdrootfs/BUILD

@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -8,6 +8,13 @@ go_library(
     deps = [
         "//src/undocker/rootfs:go_default_library",
         "@com_github_jessevdk_go_flags//:go_default_library",
+        "@com_github_ulikunitz_xz//:go_default_library",
         "@org_uber_go_multierr//:go_default_library",
     ],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["cmdrootfs_test.go"],
+    embed = [":go_default_library"],
+)

internal/cmdrootfs/cmdrootfs.go

@@ -2,10 +2,12 @@ package cmdrootfs
 
 import (
 	"errors"
+	"io"
 	"os"
 
 	goflags "github.com/jessevdk/go-flags"
 	"github.com/motiejus/code/undocker/rootfs"
+	"github.com/ulikunitz/xz"
 	"go.uber.org/multierr"
 )
 
@@ -15,6 +17,10 @@ type Command struct {
 		Infile  goflags.Filename `long:"infile" description:"Input tarball"`
 		Outfile string           `long:"outfile" description:"Output path, stdout is '-'"`
 	} `positional-args:"yes" required:"yes"`
+
+	Xz bool `short:"J" long:"xz" description:"create XZ archive"`
+
+	rootfsNew func(io.ReadSeeker) io.WriterTo
 }
 
 // Execute executes rootfs Command
@@ -22,6 +28,11 @@ func (c *Command) Execute(args []string) (err error) {
 	if len(args) != 0 {
 		return errors.New("too many args")
 	}
+	if c.rootfsNew == nil {
+		c.rootfsNew = func(r io.ReadSeeker) io.WriterTo {
+			return rootfs.New(r)
+		}
+	}
 
 	rd, err := os.Open(string(c.PositionalArgs.Infile))
 	if err != nil {
@@ -29,7 +40,7 @@ func (c *Command) Execute(args []string) (err error) {
 	}
 	defer func() { err = multierr.Append(err, rd.Close()) }()
 
-	var out *os.File
+	var out io.WriteCloser
 	outf := string(c.PositionalArgs.Outfile)
 	if outf == "-" {
 		out = os.Stdout
@@ -41,5 +52,15 @@ func (c *Command) Execute(args []string) (err error) {
 	}
 	defer func() { err = multierr.Append(err, out.Close()) }()
 
-	return rootfs.New(rd).WriteTo(out)
+	if c.Xz {
+		if out, err = xz.NewWriter(out); err != nil {
+			return err
+		}
+		defer func() { err = multierr.Append(err, out.Close()) }()
+	}
+
+	if _, err := c.rootfsNew(rd).WriteTo(out); err != nil {
+		return err
+	}
+	return nil
 }

internal/cmdrootfs/cmdrootfs_test.go

@@ -0,0 +1,7 @@
+package cmdrootfs
+
+import "testing"
+
+func TestExecute(t *testing.T) {
+
+}