Engine: 'create' creates a container and prints its ID on stdout

api.go

@@ -526,43 +526,36 @@ func postContainersCreate(srv *Server, version float64, w http.ResponseWriter, r
 	if err := parseForm(r); err != nil {
 		return nil
 	}
-	config := &Config{}
 	out := &APIRun{}
-	name := r.Form.Get("name")
-
-	if err := json.NewDecoder(r.Body).Decode(config); err != nil {
+	job := srv.Eng.Job("create", r.Form.Get("name"))
+	if err := job.DecodeEnv(r.Body); err != nil {
 		return err
 	}
-
 	resolvConf, err := utils.GetResolvConf()
 	if err != nil {
 		return err
 	}
-
-	if !config.NetworkDisabled && len(config.Dns) == 0 && len(srv.runtime.config.Dns) == 0 && utils.CheckLocalDns(resolvConf) {
+	if !job.GetenvBool("NetworkDisabled") && len(job.Getenv("Dns")) == 0 && len(srv.runtime.config.Dns) == 0 && utils.CheckLocalDns(resolvConf) {
 		out.Warnings = append(out.Warnings, fmt.Sprintf("Docker detected local DNS server on resolv.conf. Using default external servers: %v", defaultDns))
-		config.Dns = defaultDns
+		job.SetenvList("Dns", defaultDns)
 	}
-
-	id, warnings, err := srv.ContainerCreate(config, name)
-	if err != nil {
+	// Read container ID from the first line of stdout
+	job.StdoutParseString(&out.ID)
+	// Read warnings from stderr
+	job.StderrParseLines(&out.Warnings, 0)
+	if err := job.Run(); err != nil {
 		return err
 	}
-	out.ID = id
-	for _, warning := range warnings {
-		out.Warnings = append(out.Warnings, warning)
-	}
-
-	if config.Memory > 0 && !srv.runtime.capabilities.MemoryLimit {
+	if job.GetenvInt("Memory") > 0 && !srv.runtime.capabilities.MemoryLimit {
 		log.Println("WARNING: Your kernel does not support memory limit capabilities. Limitation discarded.")
 		out.Warnings = append(out.Warnings, "Your kernel does not support memory limit capabilities. Limitation discarded.")
 	}
-	if config.Memory > 0 && !srv.runtime.capabilities.SwapLimit {
+	if job.GetenvInt("Memory") > 0 && !srv.runtime.capabilities.SwapLimit {
 		log.Println("WARNING: Your kernel does not support swap limit capabilities. Limitation discarded.")
 		out.Warnings = append(out.Warnings, "Your kernel does not support memory swap capabilities. Limitation discarded.")
 	}
 
-	if !config.NetworkDisabled && srv.runtime.capabilities.IPv4ForwardingDisabled {
+	if !job.GetenvBool("NetworkDisabled") && srv.runtime.capabilities.IPv4ForwardingDisabled {
 		log.Println("Warning: IPv4 forwarding is disabled.")
 		out.Warnings = append(out.Warnings, "IPv4 forwarding is disabled.")
 	}

api_test.go

@@ -634,11 +634,11 @@ func TestPostCommit(t *testing.T) {
 }
 
 func TestPostContainersCreate(t *testing.T) {
-	runtime := mkRuntime(t)
+	eng := NewTestEngine(t)
+	srv := mkServerFromEngine(eng, t)
+	runtime := srv.runtime
 	defer nuke(runtime)
 
-	srv := &Server{runtime: runtime}
-
 	configJSON, err := json.Marshal(&Config{
 		Image:  GetTestImage(runtime).ID,
 		Memory: 33554432,
@@ -786,22 +786,18 @@ func TestPostContainersStart(t *testing.T) {
 	runtime := srv.runtime
 	defer nuke(runtime)
 
-	container, _, err := runtime.Create(
+	id := createTestContainer(
+		eng,
 		&Config{
 			Image:     GetTestImage(runtime).ID,
 			Cmd:       []string{"/bin/cat"},
 			OpenStdin: true,
 		},
-		"",
-	)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer runtime.Destroy(container)
+		t)
 
 	hostConfigJSON, err := json.Marshal(&HostConfig{})
 
-	req, err := http.NewRequest("POST", "/containers/"+container.ID+"/start", bytes.NewReader(hostConfigJSON))
+	req, err := http.NewRequest("POST", "/containers/"+id+"/start", bytes.NewReader(hostConfigJSON))
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -809,22 +805,26 @@ func TestPostContainersStart(t *testing.T) {
 	req.Header.Set("Content-Type", "application/json")
 
 	r := httptest.NewRecorder()
-	if err := postContainersStart(srv, APIVERSION, r, req, map[string]string{"name": container.ID}); err != nil {
+	if err := postContainersStart(srv, APIVERSION, r, req, map[string]string{"name": id}); err != nil {
 		t.Fatal(err)
 	}
 	if r.Code != http.StatusNoContent {
 		t.Fatalf("%d NO CONTENT expected, received %d\n", http.StatusNoContent, r.Code)
 	}
 
+	container := runtime.Get(id)
+	if container == nil {
+		t.Fatalf("Container %s was not created", id)
+	}
 	// Give some time to the process to start
+	// FIXME: use Wait once it's available as a job
 	container.WaitTimeout(500 * time.Millisecond)
-
 	if !container.State.Running {
 		t.Errorf("Container should be running")
 	}
 
 	r = httptest.NewRecorder()
-	if err = postContainersStart(srv, APIVERSION, r, req, map[string]string{"name": container.ID}); err == nil {
+	if err = postContainersStart(srv, APIVERSION, r, req, map[string]string{"name": id}); err == nil {
 		t.Fatalf("A running container should be able to be started")
 	}
 

engine/engine.go

@@ -115,5 +115,5 @@ func (eng *Engine) Job(name string, args ...string) *Job {
 
 func (eng *Engine) Logf(format string, args ...interface{}) (n int, err error) {
 	prefixedFormat := fmt.Sprintf("[%s] %s\n", eng, strings.TrimRight(format, "\n"))
-	return fmt.Printf(prefixedFormat, args...)
+	return fmt.Fprintf(os.Stderr, prefixedFormat, args...)
 }

engine/job.go

@@ -1,11 +1,16 @@
 package engine
 
 import (
+	"bufio"
 	"bytes"
 	"io"
+	"io/ioutil"
+	"strconv"
 	"strings"
 	"fmt"
+	"sync"
 	"encoding/json"
+	"os"
 )
 
 // A job is the fundamental unit of work in the docker engine.
@@ -26,20 +31,38 @@ type Job struct {
 	Name	string
 	Args	[]string
 	env	[]string
-	Stdin	io.ReadCloser
-	Stdout	io.WriteCloser
-	Stderr	io.WriteCloser
+	Stdin	io.Reader
+	Stdout	io.Writer
+	Stderr	io.Writer
 	handler	func(*Job) string
 	status	string
+	onExit	[]func()
 }
 
 // Run executes the job and blocks until the job completes.
 // If the job returns a failure status, an error is returned
 // which includes the status.
 func (job *Job) Run() error {
-	job.Logf("{")
 	defer func() {
-		job.Logf("}")
+		var wg sync.WaitGroup
+		for _, f := range job.onExit {
+			wg.Add(1)
+			go func(f func()) {
+				f()
+				wg.Done()
+			}(f)
+		}
+		wg.Wait()
+	}()
+	if job.Stdout != nil && job.Stdout != os.Stdout {
+		job.Stdout = io.MultiWriter(job.Stdout, os.Stdout)
+	}
+	if job.Stderr != nil && job.Stderr != os.Stderr {
+		job.Stderr = io.MultiWriter(job.Stderr, os.Stderr)
+	}
+	job.Eng.Logf("+job %s", job.CallString())
+	defer func() {
+		job.Eng.Logf("-job %s%s", job.CallString(), job.StatusString())
 	}()
 	if job.handler == nil {
 		job.status = "command not found"
@@ -52,9 +75,66 @@ func (job *Job) Run() error {
 	return nil
 }
 
-// String returns a human-readable description of `job`
-func (job *Job) String() string {
-	s := fmt.Sprintf("%s.%s(%s)", job.Eng, job.Name, strings.Join(job.Args, ", "))
+func (job *Job) StdoutParseLines(dst *[]string, limit int) {
+	job.parseLines(job.StdoutPipe(), dst, limit)
+}
+
+func (job *Job) StderrParseLines(dst *[]string, limit int) {
+	job.parseLines(job.StderrPipe(), dst, limit)
+}
+
+func (job *Job) parseLines(src io.Reader, dst *[]string, limit int) {
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		scanner := bufio.NewScanner(src)
+		for scanner.Scan() {
+			// If the limit is reached, flush the rest of the source and return
+			if limit > 0 && len(*dst) >= limit {
+				io.Copy(ioutil.Discard, src)
+				return
+			}
+			line := scanner.Text()
+			// Append the line (with delimitor removed)
+			*dst = append(*dst, line)
+		}
+	}()
+	job.onExit = append(job.onExit, wg.Wait)
+}
+
+func (job *Job) StdoutParseString(dst *string) {
+	lines := make([]string, 0, 1)
+	job.StdoutParseLines(&lines, 1)
+	job.onExit = append(job.onExit, func() { if len(lines) >= 1 { *dst = lines[0] }})
+}
+
+func (job *Job) StderrParseString(dst *string) {
+	lines := make([]string, 0, 1)
+	job.StderrParseLines(&lines, 1)
+	job.onExit = append(job.onExit, func() { *dst = lines[0]; })
+}
+
+func (job *Job) StdoutPipe() io.ReadCloser {
+	r, w := io.Pipe()
+	job.Stdout = w
+	job.onExit = append(job.onExit, func(){ w.Close() })
+	return r
+}
+
+func (job *Job) StderrPipe() io.ReadCloser {
+	r, w := io.Pipe()
+	job.Stderr = w
+	job.onExit = append(job.onExit, func(){ w.Close() })
+	return r
+}
+
+
+func (job *Job) CallString() string {
+	return fmt.Sprintf("%s(%s)", job.Name, strings.Join(job.Args, ", "))
+}
+
+func (job *Job) StatusString() string {
 	// FIXME: if a job returns the empty string, it will be printed
 	// as not having returned.
 	// (this only affects String which is a convenience function).
@@ -65,9 +145,14 @@ func (job *Job) String() string {
 		} else {
 			okerr = "ERR"
 		}
-		s = fmt.Sprintf("%s = %s (%s)", s, okerr, job.status)
+		return fmt.Sprintf(" = %s (%s)", okerr, job.status)
 	}
-	return s
+	return ""
+}
+
+// String returns a human-readable description of `job`
+func (job *Job) String() string {
+	return fmt.Sprintf("%s.%s%s", job.Eng, job.CallString(), job.StatusString())
 }
 
 func (job *Job) Getenv(key string) (value string) {
@@ -104,6 +189,19 @@ func (job *Job) SetenvBool(key string, value bool) {
 	}
 }
 
+func (job *Job) GetenvInt(key string) int64 {
+	s := strings.Trim(job.Getenv(key), " \t")
+	val, err := strconv.ParseInt(s, 10, 64)
+	if err != nil {
+		return -1
+	}
+	return val
+}
+
+func (job *Job) SetenvInt(key string, value int64) {
+	job.Setenv(key, fmt.Sprintf("%d", value))
+}
+
 func (job *Job) GetenvList(key string) []string {
 	sval := job.Getenv(key)
 	l := make([]string, 0, 1)
@@ -137,13 +235,21 @@ func (job *Job) DecodeEnv(src io.Reader) error {
 		return err
 	}
 	for k, v := range m {
-		if sval, ok := v.(string); ok {
+		// FIXME: we fix-convert float values to int, because
+		// encoding/json decodes integers to float64, but cannot encode them back.
+		// (See http://golang.org/src/pkg/encoding/json/decode.go#L46)
+		if fval, ok := v.(float64); ok {
+			job.Logf("Converted to float: %v->%v", v, fval)
+			job.SetenvInt(k, int64(fval))
+		} else if sval, ok := v.(string); ok {
+			job.Logf("Converted to string: %v->%v", v, sval)
 			job.Setenv(k, sval)
 		} else	if val, err := json.Marshal(v); err == nil {
 			job.Setenv(k, string(val))
 		} else {
 			job.Setenv(k, fmt.Sprintf("%v", v))
 		}
+		job.Logf("Decoded %s=%#v to %s=%#v", k, v, k, job.Getenv(k))
 	}
 	return nil
 }
@@ -153,10 +259,17 @@ func (job *Job) EncodeEnv(dst io.Writer) error {
 	for k, v := range job.Environ() {
 		var val interface{}
 		if err := json.Unmarshal([]byte(v), &val); err == nil {
+			// FIXME: we fix-convert float values to int, because
+			// encoding/json decodes integers to float64, but cannot encode them back.
+			// (See http://golang.org/src/pkg/encoding/json/decode.go#L46)
+			if fval, isFloat := val.(float64); isFloat {
+				val = int(fval)
+			}
 			m[k] = val
 		} else {
 			m[k] = v
 		}
+		job.Logf("Encoded %s=%#v to %s=%#v", k, v, k, m[k])
 	}
 	if err := json.NewEncoder(dst).Encode(&m); err != nil {
 		return err
@@ -165,21 +278,38 @@ func (job *Job) EncodeEnv(dst io.Writer) error {
 }
 
 func (job *Job) ExportEnv(dst interface{}) (err error) {
+	fmt.Fprintf(os.Stderr, "ExportEnv()\n")
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("ExportEnv %s", err)
+		}
+	}()
 	var buf bytes.Buffer
+	job.Logf("ExportEnv: step 1: encode/marshal the env to an intermediary json representation")
+	fmt.Fprintf(os.Stderr, "Printed ExportEnv step 1\n")
 	if err := job.EncodeEnv(&buf); err != nil {
 		return err
 	}
+	job.Logf("ExportEnv: step 1 complete: json=|%s|", buf)
+	job.Logf("ExportEnv: step 2: decode/unmarshal the intermediary json into the destination object")
 	if err := json.NewDecoder(&buf).Decode(dst); err != nil {
 		return err
 	}
+	job.Logf("ExportEnv: step 2 complete")
 	return nil
 }
 
-func (job *Job) ImportEnv(src interface{}) error {
+func (job *Job) ImportEnv(src interface{}) (err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("ImportEnv: %s", err)
+		}
+	}()
 	var buf bytes.Buffer
 	if err := json.NewEncoder(&buf).Encode(src); err != nil {
 		return err
 	}
+	job.Logf("ImportEnv: json=|%s|", buf)
 	if err := job.DecodeEnv(&buf); err != nil {
 		return err
 	}
@@ -197,5 +327,14 @@ func (job *Job) Environ() map[string]string {
 
 func (job *Job) Logf(format string, args ...interface{}) (n int, err error) {
 	prefixedFormat := fmt.Sprintf("[%s] %s\n", job, strings.TrimRight(format, "\n"))
-	return fmt.Fprintf(job.Stdout, prefixedFormat, args...)
+	return fmt.Fprintf(job.Stderr, prefixedFormat, args...)
+}
+
+func (job *Job) Printf(format string, args ...interface{}) (n int, err error) {
+	return fmt.Fprintf(job.Stdout, format, args...)
+}
+
+func (job *Job) Errorf(format string, args ...interface{}) (n int, err error) {
+	return fmt.Fprintf(job.Stderr, format, args...)
+
 }

runtime_test.go

@@ -645,20 +645,17 @@ func TestReloadContainerLinks(t *testing.T) {
 }
 
 func TestDefaultContainerName(t *testing.T) {
-	runtime := mkRuntime(t)
+	eng := NewTestEngine(t)
+	srv := mkServerFromEngine(eng, t)
+	runtime := srv.runtime
 	defer nuke(runtime)
-	srv := &Server{runtime: runtime}
 
 	config, _, _, err := ParseRun([]string{GetTestImage(runtime).ID, "echo test"}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	shortId, _, err := srv.ContainerCreate(config, "some_name")
-	if err != nil {
-		t.Fatal(err)
-	}
-	container := runtime.Get(shortId)
+	container := runtime.Get(createNamedTestContainer(eng, config, t, "some_name"))
 	containerID := container.ID
 
 	if container.Name != "/some_name" {
@@ -682,20 +679,17 @@ func TestDefaultContainerName(t *testing.T) {
 }
 
 func TestRandomContainerName(t *testing.T) {
-	runtime := mkRuntime(t)
+	eng := NewTestEngine(t)
+	srv := mkServerFromEngine(eng, t)
+	runtime := srv.runtime
 	defer nuke(runtime)
-	srv := &Server{runtime: runtime}
 
 	config, _, _, err := ParseRun([]string{GetTestImage(runtime).ID, "echo test"}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	shortId, _, err := srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
-	container := runtime.Get(shortId)
+	container := runtime.Get(createTestContainer(eng, config, t))
 	containerID := container.ID
 
 	if container.Name == "" {
@@ -719,20 +713,17 @@ func TestRandomContainerName(t *testing.T) {
 }
 
 func TestLinkChildContainer(t *testing.T) {
-	runtime := mkRuntime(t)
+	eng := NewTestEngine(t)
+	srv := mkServerFromEngine(eng, t)
+	runtime := srv.runtime
 	defer nuke(runtime)
-	srv := &Server{runtime: runtime}
 
 	config, _, _, err := ParseRun([]string{GetTestImage(runtime).ID, "echo test"}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	shortId, _, err := srv.ContainerCreate(config, "/webapp")
-	if err != nil {
-		t.Fatal(err)
-	}
-	container := runtime.Get(shortId)
+	container := runtime.Get(createNamedTestContainer(eng, config, t, "/webapp"))
 
 	webapp, err := runtime.GetByName("/webapp")
 	if err != nil {
@@ -748,12 +739,7 @@ func TestLinkChildContainer(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	shortId, _, err = srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	childContainer := runtime.Get(shortId)
+	childContainer := runtime.Get(createTestContainer(eng, config, t))
 
 	if err := runtime.RegisterLink(webapp, childContainer, "db"); err != nil {
 		t.Fatal(err)
@@ -770,20 +756,17 @@ func TestLinkChildContainer(t *testing.T) {
 }
 
 func TestGetAllChildren(t *testing.T) {
-	runtime := mkRuntime(t)
+	eng := NewTestEngine(t)
+	srv := mkServerFromEngine(eng, t)
+	runtime := srv.runtime
 	defer nuke(runtime)
-	srv := &Server{runtime: runtime}
 
 	config, _, _, err := ParseRun([]string{GetTestImage(runtime).ID, "echo test"}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	shortId, _, err := srv.ContainerCreate(config, "/webapp")
-	if err != nil {
-		t.Fatal(err)
-	}
-	container := runtime.Get(shortId)
+	container := runtime.Get(createNamedTestContainer(eng, config, t, "/webapp"))
 
 	webapp, err := runtime.GetByName("/webapp")
 	if err != nil {
@@ -799,12 +782,7 @@ func TestGetAllChildren(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	shortId, _, err = srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	childContainer := runtime.Get(shortId)
+	childContainer := runtime.Get(createTestContainer(eng, config, t))
 
 	if err := runtime.RegisterLink(webapp, childContainer, "db"); err != nil {
 		t.Fatal(err)

server.go

@@ -62,6 +62,9 @@ func jobInitApi(job *engine.Job) string {
 		os.Exit(0)
 	}()
 	job.Eng.Hack_SetGlobalVar("httpapi.server", srv)
+	if err := job.Eng.Register("create", srv.ContainerCreate); err != nil {
+		return err.Error()
+	}
 	if err := job.Eng.Register("start", srv.ContainerStart); err != nil {
 		return err.Error()
 	}
@@ -1009,33 +1012,43 @@ func (srv *Server) ImageImport(src, repo, tag string, in io.Reader, out io.Write
 	return nil
 }
 
-func (srv *Server) ContainerCreate(config *Config, name string) (string, []string, error) {
+func (srv *Server) ContainerCreate(job *engine.Job) string {
+	var name string
+	if len(job.Args) == 1 {
+		name = job.Args[0]
+	} else if len(job.Args) > 1 {
+		return fmt.Sprintf("Usage: %s ", job.Name)
+	}
+	var config Config
+	if err := job.ExportEnv(&config); err != nil {
+		return err.Error()
+	}
 	if config.Memory != 0 && config.Memory < 524288 {
-		return "", nil, fmt.Errorf("Memory limit must be given in bytes (minimum 524288 bytes)")
+		return "Memory limit must be given in bytes (minimum 524288 bytes)"
 	}
-
 	if config.Memory > 0 && !srv.runtime.capabilities.MemoryLimit {
 		config.Memory = 0
 	}
-
 	if config.Memory > 0 && !srv.runtime.capabilities.SwapLimit {
 		config.MemorySwap = -1
 	}
-	container, buildWarnings, err := srv.runtime.Create(config, name)
+	container, buildWarnings, err := srv.runtime.Create(&config, name)
 	if err != nil {
 		if srv.runtime.graph.IsNotExist(err) {
-
 			_, tag := utils.ParseRepositoryTag(config.Image)
 			if tag == "" {
 				tag = DEFAULTTAG
 			}
-
-			return "", nil, fmt.Errorf("No such image: %s (tag: %s)", config.Image, tag)
+			return fmt.Sprintf("No such image: %s (tag: %s)", config.Image, tag)
 		}
-		return "", nil, err
+		return err.Error()
 	}
 	srv.LogEvent("create", container.ShortID(), srv.runtime.repositories.ImageName(container.Image))
-	return container.ShortID(), buildWarnings, nil
+	job.Printf("%s\n", container.ShortID())
+	for _, warning := range buildWarnings {
+		job.Errorf("%s\n", warning)
+	}
+	return "0"
 }
 
 func (srv *Server) ContainerRestart(name string, t int) error {

server_test.go

@@ -79,20 +79,17 @@ func TestContainerTagImageDelete(t *testing.T) {
 }
 
 func TestCreateRm(t *testing.T) {
-	runtime := mkRuntime(t)
+	eng := NewTestEngine(t)
+	srv := mkServerFromEngine(eng, t)
+	runtime := srv.runtime
 	defer nuke(runtime)
 
-	srv := &Server{runtime: runtime}
-
 	config, _, _, err := ParseRun([]string{GetTestImage(runtime).ID, "echo test"}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	id, _, err := srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	id := createTestContainer(eng, config, t)
 
 	if len(runtime.List()) != 1 {
 		t.Errorf("Expected 1 container, %v found", len(runtime.List()))
@@ -120,10 +117,7 @@ func TestCreateRmVolumes(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	id, _, err := srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	id := createTestContainer(eng, config, t)
 
 	if len(runtime.List()) != 1 {
 		t.Errorf("Expected 1 container, %v found", len(runtime.List()))
@@ -152,20 +146,17 @@ func TestCreateRmVolumes(t *testing.T) {
 }
 
 func TestCommit(t *testing.T) {
-	runtime := mkRuntime(t)
+	eng := NewTestEngine(t)
+	srv := mkServerFromEngine(eng, t)
+	runtime := srv.runtime
 	defer nuke(runtime)
 
-	srv := &Server{runtime: runtime}
-
 	config, _, _, err := ParseRun([]string{GetTestImage(runtime).ID, "/bin/cat"}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	id, _, err := srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	id := createTestContainer(eng, config, t)
 
 	if _, err := srv.ContainerCommit(id, "testrepo", "testtag", "", "", config); err != nil {
 		t.Fatal(err)
@@ -183,10 +174,7 @@ func TestCreateStartRestartStopStartKillRm(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	id, _, err := srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	id := createTestContainer(eng, config, t)
 
 	if len(runtime.List()) != 1 {
 		t.Errorf("Expected 1 container, %v found", len(runtime.List()))
@@ -232,22 +220,22 @@ func TestCreateStartRestartStopStartKillRm(t *testing.T) {
 }
 
 func TestRunWithTooLowMemoryLimit(t *testing.T) {
-	runtime := mkRuntime(t)
+	eng := NewTestEngine(t)
+	srv := mkServerFromEngine(eng, t)
+	runtime := srv.runtime
 	defer nuke(runtime)
 
 	// Try to create a container with a memory limit of 1 byte less than the minimum allowed limit.
-	if _, _, err := (*Server).ContainerCreate(&Server{runtime: runtime},
-		&Config{
-			Image:     GetTestImage(runtime).ID,
-			Memory:    524287,
-			CpuShares: 1000,
-			Cmd:       []string{"/bin/cat"},
-		},
-		"",
-	); err == nil {
+	job := eng.Job("create")
+	job.Setenv("Image", GetTestImage(runtime).ID)
+	job.Setenv("Memory", "524287")
+	job.Setenv("CpuShares", "1000")
+	job.SetenvList("Cmd", []string{"/bin/cat"})
+	var id string
+	job.StdoutParseString(&id)
+	if err := job.Run(); err == nil {
 		t.Errorf("Memory limit is smaller than the allowed limit. Container creation should've failed!")
 	}
-
 }
 
 func TestContainerTop(t *testing.T) {
@@ -411,10 +399,7 @@ func TestRmi(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	containerID, _, err := srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	containerID := createTestContainer(eng, config, t)
 
 	//To remove
 	job := eng.Job("start", containerID)
@@ -435,10 +420,7 @@ func TestRmi(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	containerID, _, err = srv.ContainerCreate(config, "")
-	if err != nil {
-		t.Fatal(err)
-	}
+	containerID = createTestContainer(eng, config, t)
 
 	//To remove
 	job = eng.Job("start", containerID)

utils_test.go

@@ -38,6 +38,22 @@ func mkRuntime(f utils.Fataler) *Runtime {
 	return r
 }
 
+func createNamedTestContainer(eng *engine.Engine, config *Config, f utils.Fataler, name string) (shortId string) {
+	job := eng.Job("create", name)
+	if err := job.ImportEnv(config); err != nil {
+		f.Fatal(err)
+	}
+	job.StdoutParseString(&shortId)
+	if err := job.Run(); err != nil {
+		f.Fatal(err)
+	}
+	return
+}
+
+func createTestContainer(eng *engine.Engine, config *Config, f utils.Fataler) (shortId string) {
+	return createNamedTestContainer(eng, config, f, "")
+}
+
 func mkServerFromEngine(eng *engine.Engine, t utils.Fataler) *Server {
 	iSrv := eng.Hack_GetGlobalVar("httpapi.server")
 	if iSrv == nil {