Port 'docker images' to the engine API

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)

api.go

@@ -181,27 +181,19 @@ func getImagesJSON(srv *Server, version float64, w http.ResponseWriter, r *http.
 	if err := parseForm(r); err != nil {
 		return err
 	}
-
-	all, err := getBoolParam(r.Form.Get("all"))
-	if err != nil {
-		return err
-	}
-	filter := r.Form.Get("filter")
-
-	outs, err := srv.Images(all, filter)
-	if err != nil {
+	fmt.Printf("getImagesJSON\n")
+	job := srv.Eng.Job("images")
+	job.Setenv("filter", r.Form.Get("filter"))
+	job.Setenv("all", r.Form.Get("all"))
+	// FIXME: 1.7 clients expect a single json list
+	job.Stdout.Add(w)
+	w.WriteHeader(http.StatusOK)
+	fmt.Printf("running images job\n")
+	if err := job.Run(); err != nil {
 		return err
 	}
-
-	if version < 1.7 {
-		outs2 := []APIImagesOld{}
-		for _, ctnr := range outs {
-			outs2 = append(outs2, ctnr.ToLegacy()...)
-		}
-
-		return writeJSON(w, http.StatusOK, outs2)
-	}
-	return writeJSON(w, http.StatusOK, outs)
+	fmt.Printf("job has been run\n")
+	return nil
 }
 
 func getImagesViz(srv *Server, version float64, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

engine/env.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"sort"
 	"strconv"
 	"strings"
 )
@@ -232,3 +233,76 @@ func (env *Env) Map() map[string]string {
 	}
 	return m
 }
+
+type Table struct {
+	Data    []*Env
+	sortKey string
+}
+
+func NewTable(sortKey string, sizeHint int) *Table {
+	return &Table{
+		make([]*Env, 0, sizeHint),
+		sortKey,
+	}
+}
+
+func (t *Table) Add(env *Env) {
+	t.Data = append(t.Data, env)
+}
+
+func (t *Table) Len() int {
+	return len(t.Data)
+}
+
+func (t *Table) Less(a, b int) bool {
+	return t.lessBy(a, b, t.sortKey)
+}
+
+func (t *Table) lessBy(a, b int, by string) bool {
+	keyA := t.Data[a].Get(by)
+	keyB := t.Data[b].Get(by)
+	intA, errA := strconv.ParseInt(keyA, 10, 64)
+	intB, errB := strconv.ParseInt(keyB, 10, 64)
+	if errA == nil && errB == nil {
+		return intA < intB
+	}
+	return keyA < keyB
+}
+
+func (t *Table) Swap(a, b int) {
+	tmp := t.Data[a]
+	t.Data[a] = t.Data[b]
+	t.Data[b] = tmp
+}
+
+func (t *Table) Sort() {
+	sort.Sort(t)
+}
+
+func (t *Table) WriteTo(dst io.Writer) (n int64, err error) {
+	for _, env := range t.Data {
+		bytes, err := env.WriteTo(dst)
+		if err != nil {
+			return -1, err
+		}
+		if _, err := dst.Write([]byte{'\n'}); err != nil {
+			return -1, err
+		}
+		n += bytes + 1
+	}
+	return n, nil
+}
+
+func (t *Table) ReadFrom(src io.Reader) (n int64, err error) {
+	decoder := NewDecoder(src)
+	for {
+		env, err := decoder.Decode()
+		if err == io.EOF {
+			return 0, nil
+		} else if err != nil {
+			return -1, err
+		}
+		t.Add(env)
+	}
+	return 0, nil
+}

engine/streams.go

@@ -190,3 +190,19 @@ func (o *Output) AddEnv() (dst *Env, err error) {
 	}()
 	return dst, nil
 }
+
+func (o *Output) AddTable() (dst *Table, err error) {
+	src, err := o.AddPipe()
+	if err != nil {
+		return nil, err
+	}
+	dst = NewTable("", 0)
+	o.tasks.Add(1)
+	go func() {
+		defer o.tasks.Done()
+		if _, err := dst.ReadFrom(src); err != nil {
+			return
+		}
+	}()
+	return dst, nil
+}

engine/table_test.go

@@ -0,0 +1,28 @@
+package engine
+
+import (
+	"testing"
+	"bytes"
+	"encoding/json"
+)
+
+func TestTableWriteTo(t *testing.T) {
+	table := NewTable("", 0)
+	e := &Env{}
+	e.Set("foo", "bar")
+	table.Add(e)
+	var buf bytes.Buffer
+	if _, err := table.WriteTo(&buf); err != nil {
+		t.Fatal(err)
+	}
+	output := make(map[string]string)
+	if err := json.Unmarshal(buf.Bytes(), &output); err != nil {
+		t.Fatal(err)
+	}
+	if len(output) != 1  {
+		t.Fatalf("Incorrect output: %v", output)
+	}
+	if val, exists := output["foo"]; !exists || val != "bar" {
+		t.Fatalf("Inccorect output: %v", output)
+	}
+}

integration/api_test.go

@@ -60,11 +60,14 @@ func TestGetInfo(t *testing.T) {
 	defer mkRuntimeFromEngine(eng, t).Nuke()
 	srv := mkServerFromEngine(eng, t)
 
-	initialImages, err := srv.Images(false, "")
+	job := eng.Job("images")
+	initialImages, err := job.Stdout.AddTable()
 	if err != nil {
 		t.Fatal(err)
 	}
-
+	if err := job.Run(); err != nil {
+		t.Fatal(err)
+	}
 	req, err := http.NewRequest("GET", "/info", nil)
 	if err != nil {
 		t.Fatal(err)
@@ -85,8 +88,8 @@ func TestGetInfo(t *testing.T) {
 		t.Fatal(err)
 	}
 	out.Close()
-	if images := i.GetInt("Images"); images != len(initialImages) {
-		t.Errorf("Expected images: %d, %d found", len(initialImages), images)
+	if images := i.GetInt("Images"); images != initialImages.Len() {
+		t.Errorf("Expected images: %d, %d found", initialImages.Len(), images)
 	}
 	expected := "application/json"
 	if result := r.HeaderMap.Get("Content-Type"); result != expected {
@@ -145,12 +148,14 @@ func TestGetImagesJSON(t *testing.T) {
 	defer mkRuntimeFromEngine(eng, t).Nuke()
 	srv := mkServerFromEngine(eng, t)
 
-	// all=0
-
-	initialImages, err := srv.Images(false, "")
+	job := eng.Job("images")
+	initialImages, err := job.Stdout.AddTable()
 	if err != nil {
 		t.Fatal(err)
 	}
+	if err := job.Run(); err != nil {
+		t.Fatal(err)
+	}
 
 	req, err := http.NewRequest("GET", "/images/json?all=0", nil)
 	if err != nil {
@@ -164,18 +169,18 @@ func TestGetImagesJSON(t *testing.T) {
 	}
 	assertHttpNotError(r, t)
 
-	images := []docker.APIImages{}
-	if err := json.Unmarshal(r.Body.Bytes(), &images); err != nil {
+	images := engine.NewTable("Created", 0)
+	if _, err := images.ReadFrom(r.Body); err != nil {
 		t.Fatal(err)
 	}
 
-	if len(images) != len(initialImages) {
-		t.Errorf("Expected %d image, %d found", len(initialImages), len(images))
+	if images.Len() != initialImages.Len() {
+		t.Errorf("Expected %d image, %d found", initialImages.Len(), images.Len())
 	}
 
 	found := false
-	for _, img := range images {
-		if strings.Contains(img.RepoTags[0], unitTestImageName) {
+	for _, img := range images.Data {
+		if strings.Contains(img.GetList("RepoTags")[0], unitTestImageName) {
 			found = true
 			break
 		}
@@ -188,10 +193,7 @@ func TestGetImagesJSON(t *testing.T) {
 
 	// all=1
 
-	initialImages, err = srv.Images(true, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	initialImages = getAllImages(eng, t)
 
 	req2, err := http.NewRequest("GET", "/images/json?all=true", nil)
 	if err != nil {
@@ -207,8 +209,8 @@ func TestGetImagesJSON(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if len(images2) != len(initialImages) {
-		t.Errorf("Expected %d image, %d found", len(initialImages), len(images2))
+	if len(images2) != initialImages.Len() {
+		t.Errorf("Expected %d image, %d found", initialImages.Len(), len(images2))
 	}
 
 	found = false
@@ -1126,21 +1128,16 @@ func TestDeleteImages(t *testing.T) {
 	defer mkRuntimeFromEngine(eng, t).Nuke()
 	srv := mkServerFromEngine(eng, t)
 
-	initialImages, err := srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	initialImages := getImages(eng, t, true, "")
 
 	if err := eng.Job("tag", unitTestImageName, "test", "test").Run(); err != nil {
 		t.Fatal(err)
 	}
-	images, err := srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
 
-	if len(images[0].RepoTags) != len(initialImages[0].RepoTags)+1 {
-		t.Errorf("Expected %d images, %d found", len(initialImages)+1, len(images))
+	images := getImages(eng, t, true, "")
+
+	if images.Len() != initialImages.Len()+1 {
+		t.Errorf("Expected %d images, %d found", initialImages.Len()+1, images.Len())
 	}
 
 	req, err := http.NewRequest("DELETE", "/images/"+unitTestImageID, nil)
@@ -1177,13 +1174,10 @@ func TestDeleteImages(t *testing.T) {
 	if len(outs) != 1 {
 		t.Fatalf("Expected %d event (untagged), got %d", 1, len(outs))
 	}
-	images, err = srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images = getImages(eng, t, false, "")
 
-	if len(images[0].RepoTags) != len(initialImages[0].RepoTags) {
-		t.Errorf("Expected %d image, %d found", len(initialImages), len(images))
+	if images.Len() != initialImages.Len() {
+		t.Errorf("Expected %d image, %d found", initialImages.Len(), images.Len())
 	}
 }
 

integration/runtime_test.go

@@ -51,14 +51,17 @@ func cleanup(eng *engine.Engine, t *testing.T) error {
 		container.Kill()
 		runtime.Destroy(container)
 	}
-	srv := mkServerFromEngine(eng, t)
-	images, err := srv.Images(true, "")
+	job := eng.Job("images")
+	images, err := job.Stdout.AddTable()
 	if err != nil {
-		return err
+		t.Fatal(err)
+	}
+	if err := job.Run(); err != nil {
+		t.Fatal(err)
 	}
-	for _, image := range images {
-		if image.ID != unitTestImageID {
-			srv.ImageDelete(image.ID, false)
+	for _, image := range images.Data {
+		if image.Get("ID") != unitTestImageID {
+			mkServerFromEngine(eng, t).ImageDelete(image.Get("ID"), false)
 		}
 	}
 	return nil
@@ -158,7 +161,7 @@ func spawnGlobalDaemon() {
 			Host:   testDaemonAddr,
 		}
 		job := eng.Job("serveapi", listenURL.String())
-		job.SetenvBool("Logging", os.Getenv("DEBUG") != "")
+		job.SetenvBool("Logging", true)
 		if err := job.Run(); err != nil {
 			log.Fatalf("Unable to spawn the test daemon: %s", err)
 		}

integration/server_test.go

@@ -14,10 +14,7 @@ func TestImageTagImageDelete(t *testing.T) {
 
 	srv := mkServerFromEngine(eng, t)
 
-	initialImages, err := srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	initialImages := getAllImages(eng, t)
 	if err := eng.Job("tag", unitTestImageName, "utest", "tag1").Run(); err != nil {
 		t.Fatal(err)
 	}
@@ -30,52 +27,43 @@ func TestImageTagImageDelete(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	images, err := srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images := getAllImages(eng, t)
 
-	if len(images[0].RepoTags) != len(initialImages[0].RepoTags)+3 {
-		t.Errorf("Expected %d images, %d found", len(initialImages)+3, len(images))
+	nExpected := len(initialImages.Data[0].GetList("RepoTags")) + 3
+	nActual := len(images.Data[0].GetList("RepoTags"))
+	if nExpected != nActual {
+		t.Errorf("Expected %d images, %d found", nExpected, nActual)
 	}
 
 	if _, err := srv.ImageDelete("utest/docker:tag2", true); err != nil {
 		t.Fatal(err)
 	}
 
-	images, err = srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images = getAllImages(eng, t)
 
-	if len(images[0].RepoTags) != len(initialImages[0].RepoTags)+2 {
-		t.Errorf("Expected %d images, %d found", len(initialImages)+2, len(images))
+	nExpected = len(initialImages.Data[0].GetList("RepoTags")) + 2
+	nActual = len(images.Data[0].GetList("RepoTags"))
+	if nExpected != nActual {
+		t.Errorf("Expected %d images, %d found", nExpected, nActual)
 	}
 
 	if _, err := srv.ImageDelete("utest:5000/docker:tag3", true); err != nil {
 		t.Fatal(err)
 	}
 
-	images, err = srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images = getAllImages(eng, t)
 
-	if len(images[0].RepoTags) != len(initialImages[0].RepoTags)+1 {
-		t.Errorf("Expected %d images, %d found", len(initialImages)+1, len(images))
-	}
+	nExpected = len(initialImages.Data[0].GetList("RepoTags")) + 1
+	nActual = len(images.Data[0].GetList("RepoTags"))
 
 	if _, err := srv.ImageDelete("utest:tag1", true); err != nil {
 		t.Fatal(err)
 	}
 
-	images, err = srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images = getAllImages(eng, t)
 
-	if len(images) != len(initialImages) {
-		t.Errorf("Expected %d image, %d found", len(initialImages), len(images))
+	if images.Len() != initialImages.Len() {
+		t.Errorf("Expected %d image, %d found", initialImages.Len(), images.Len())
 	}
 }
 
@@ -250,10 +238,7 @@ func TestRmi(t *testing.T) {
 	srv := mkServerFromEngine(eng, t)
 	defer mkRuntimeFromEngine(eng, t).Nuke()
 
-	initialImages, err := srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	initialImages := getAllImages(eng, t)
 
 	config, hostConfig, _, err := docker.ParseRun([]string{unitTestImageID, "echo", "test"}, nil)
 	if err != nil {
@@ -308,13 +293,10 @@ func TestRmi(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	images, err := srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images := getAllImages(eng, t)
 
-	if len(images)-len(initialImages) != 2 {
-		t.Fatalf("Expected 2 new images, found %d.", len(images)-len(initialImages))
+	if images.Len()-initialImages.Len() != 2 {
+		t.Fatalf("Expected 2 new images, found %d.", images.Len()-initialImages.Len())
 	}
 
 	_, err = srv.ImageDelete(imageID, true)
@@ -322,20 +304,17 @@ func TestRmi(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	images, err = srv.Images(false, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images = getAllImages(eng, t)
 
-	if len(images)-len(initialImages) != 1 {
-		t.Fatalf("Expected 1 new image, found %d.", len(images)-len(initialImages))
+	if images.Len()-initialImages.Len() != 1 {
+		t.Fatalf("Expected 1 new image, found %d.", images.Len()-initialImages.Len())
 	}
 
-	for _, image := range images {
-		if strings.Contains(unitTestImageID, image.ID) {
+	for _, image := range images.Data {
+		if strings.Contains(unitTestImageID, image.Get("ID")) {
 			continue
 		}
-		if image.RepoTags[0] == "<none>:<none>" {
+		if image.GetList("RepoTags")[0] == "<none>:<none>" {
 			t.Fatalf("Expected tagged image, got untagged one.")
 		}
 	}
@@ -359,39 +338,27 @@ func TestImagesFilter(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	images, err := srv.Images(false, "utest*/*")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images := getImages(eng, t, false, "utest*/*")
 
-	if len(images[0].RepoTags) != 2 {
+	if len(images.Data[0].GetList("RepoTags")) != 2 {
 		t.Fatal("incorrect number of matches returned")
 	}
 
-	images, err = srv.Images(false, "utest")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images = getImages(eng, t, false, "utest")
 
-	if len(images[0].RepoTags) != 1 {
+	if len(images.Data[0].GetList("RepoTags")) != 1 {
 		t.Fatal("incorrect number of matches returned")
 	}
 
-	images, err = srv.Images(false, "utest*")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images = getImages(eng, t, false, "utest*")
 
-	if len(images[0].RepoTags) != 1 {
+	if len(images.Data[0].GetList("RepoTags")) != 1 {
 		t.Fatal("incorrect number of matches returned")
 	}
 
-	images, err = srv.Images(false, "*5000*/*")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images = getImages(eng, t, false, "*5000*/*")
 
-	if len(images[0].RepoTags) != 1 {
+	if len(images.Data[0].GetList("RepoTags")) != 1 {
 		t.Fatal("incorrect number of matches returned")
 	}
 }

integration/sorter_test.go

@@ -17,13 +17,10 @@ func TestServerListOrderedImagesByCreationDate(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	images, err := srv.Images(true, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images := getImages(eng, t, true, "")
 
-	if images[0].Created < images[1].Created {
-		t.Error("Expected []APIImges to be ordered by most recent creation date.")
+	if images.Data[0].GetInt("Created") < images.Data[1].GetInt("Created") {
+		t.Error("Expected images to be ordered by most recent creation date.")
 	}
 }
 
@@ -44,12 +41,9 @@ func TestServerListOrderedImagesByCreationDateAndTag(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	images, err := srv.Images(true, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	images := getImages(eng, t, true, "")
 
-	if images[0].RepoTags[0] != "repo:zed" && images[0].RepoTags[0] != "repo:bar" {
+	if images.Data[0].GetList("RepoTags")[0] != "repo:zed" && images.Data[0].GetList("RepoTags")[0] != "repo:bar" {
 		t.Errorf("Expected []APIImges to be ordered by most recent creation date. %s", images)
 	}
 }

integration/utils_test.go

@@ -186,8 +186,6 @@ func NewTestEngine(t utils.Fataler) *engine.Engine {
 	if err != nil {
 		t.Fatal(err)
 	}
-	eng.Stdout = ioutil.Discard
-	eng.Stderr = ioutil.Discard
 	// Load default plugins
 	// (This is manually copied and modified from main() until we have a more generic plugin system)
 	job := eng.Job("initapi")
@@ -329,3 +327,22 @@ func fakeTar() (io.Reader, error) {
 	tw.Close()
 	return buf, nil
 }
+
+func getAllImages(eng *engine.Engine, t *testing.T) *engine.Table {
+	return getImages(eng, t, true, "")
+}
+
+func getImages(eng *engine.Engine, t *testing.T, all bool, filter string) *engine.Table {
+	job := eng.Job("images")
+	job.SetenvBool("all", all)
+	job.Setenv("filter", filter)
+	images, err := job.Stdout.AddTable()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := job.Run(); err != nil {
+		t.Fatal(err)
+	}
+	return images
+
+}

server.go

@@ -127,6 +127,10 @@ func jobInitApi(job *engine.Job) engine.Status {
 		job.Error(err)
 		return engine.StatusErr
 	}
+	if err := job.Eng.Register("images", srv.Images); err != nil {
+		job.Error(err)
+		return engine.StatusErr
+	}
 	return engine.StatusOK
 }
 
@@ -568,23 +572,26 @@ func (srv *Server) ImagesViz(out io.Writer) error {
 	return nil
 }
 
-func (srv *Server) Images(all bool, filter string) ([]APIImages, error) {
+func (srv *Server) Images(job *engine.Job) engine.Status {
+	fmt.Printf("Images()\n")
+	srv.Eng.Job("version").Run()
 	var (
 		allImages map[string]*Image
 		err       error
 	)
-	if all {
+	if job.GetenvBool("all") {
 		allImages, err = srv.runtime.graph.Map()
 	} else {
 		allImages, err = srv.runtime.graph.Heads()
 	}
 	if err != nil {
-		return nil, err
+		job.Errorf("%s", err)
+		return engine.StatusErr
 	}
-	lookup := make(map[string]APIImages)
+	lookup := make(map[string]*engine.Env)
 	for name, repository := range srv.runtime.repositories.Repositories {
-		if filter != "" {
-			if match, _ := path.Match(filter, name); !match {
+		if job.Getenv("filter") != "" {
+			if match, _ := path.Match(job.Getenv("filter"), name); !match {
 				continue
 			}
 		}
@@ -596,48 +603,51 @@ func (srv *Server) Images(all bool, filter string) ([]APIImages, error) {
 			}
 
 			if out, exists := lookup[id]; exists {
-				out.RepoTags = append(out.RepoTags, fmt.Sprintf("%s:%s", name, tag))
-
-				lookup[id] = out
+				repotag := fmt.Sprintf("%s:%s", name, tag)
+				out.SetList("RepoTags", append(out.GetList("RepoTags"), repotag))
 			} else {
-				var out APIImages
-
+				out := &engine.Env{}
 				delete(allImages, id)
-
-				out.ParentId = image.Parent
-				out.RepoTags = []string{fmt.Sprintf("%s:%s", name, tag)}
-				out.ID = image.ID
-				out.Created = image.Created.Unix()
-				out.Size = image.Size
-				out.VirtualSize = image.getParentsSize(0) + image.Size
-
+				out.Set("ParentId", image.Parent)
+				out.SetList("RepoTags", []string{fmt.Sprintf("%s:%s", name, tag)})
+				out.Set("ID", image.ID)
+				out.SetInt64("Created", image.Created.Unix())
+				out.SetInt64("Size", image.Size)
+				out.SetInt64("VirtualSize", image.getParentsSize(0)+image.Size)
 				lookup[id] = out
 			}
 
 		}
 	}
 
-	outs := make([]APIImages, 0, len(lookup))
+	outs := engine.NewTable("Created", len(lookup))
 	for _, value := range lookup {
-		outs = append(outs, value)
+		outs.Add(value)
 	}
 
 	// Display images which aren't part of a repository/tag
-	if filter == "" {
+	if job.Getenv("filter") == "" {
 		for _, image := range allImages {
-			var out APIImages
-			out.ID = image.ID
-			out.ParentId = image.Parent
-			out.RepoTags = []string{"<none>:<none>"}
-			out.Created = image.Created.Unix()
-			out.Size = image.Size
-			out.VirtualSize = image.getParentsSize(0) + image.Size
-			outs = append(outs, out)
+			out := &engine.Env{}
+			out.Set("ParentId", image.Parent)
+			out.SetList("RepoTags", []string{"<none>:<none>"})
+			out.Set("ID", image.ID)
+			out.SetInt64("Created", image.Created.Unix())
+			out.SetInt64("Size", image.Size)
+			out.SetInt64("VirtualSize", image.getParentsSize(0)+image.Size)
+			outs.Add(out)
 		}
 	}
 
-	sortImagesByCreationAndTag(outs)
-	return outs, nil
+	outs.Sort()
+	job.Logf("Sending %d images to stdout", outs.Len())
+	if n, err := outs.WriteTo(job.Stdout); err != nil {
+		job.Errorf("%s", err)
+		return engine.StatusErr
+	} else {
+		job.Logf("%d bytes sent", n)
+	}
+	return engine.StatusOK
 }
 
 func (srv *Server) DockerInfo(job *engine.Job) engine.Status {