Consolidating imaging pulling logic

pkg/kubelet/images/image_manager.go

@@ -27,25 +27,29 @@ import (
 	"k8s.io/kubernetes/pkg/util/flowcontrol"
 )
 
-// imagePuller pulls the image using Runtime.PullImage().
+// imageManager provides the functionalities for image pulling.
-// It will check the presence of the image, and report the 'image pulling',
+type imageManager struct {
-// 'image pulled' events correspondingly.
-type parallelImagePuller struct {
 	recorder record.EventRecorder
 	runtime  kubecontainer.Runtime
 	backOff  *flowcontrol.Backoff
+	// It will check the presence of the image, and report the 'image pulling', image pulled' events correspondingly.
+	puller imagePuller
 }
 
-// enforce compatibility.
+var _ ImageManager = &imageManager{}
-var _ imagePuller = &parallelImagePuller{}
 
-// NewImagePuller takes an event recorder and container runtime to create a
+func NewImageManager(recorder record.EventRecorder, runtime kubecontainer.Runtime, imageBackOff *flowcontrol.Backoff, serialized bool) ImageManager {
-// image puller that wraps the container runtime's PullImage interface.
+	var puller imagePuller
-func newParallelImagePuller(recorder record.EventRecorder, runtime kubecontainer.Runtime, imageBackOff *flowcontrol.Backoff) imagePuller {
+	if serialized {
-	return &parallelImagePuller{
+		puller = newSerialImagePuller(runtime)
+	} else {
+		puller = newParallelImagePuller(runtime)
+	}
+	return &imageManager{
 		recorder: recorder,
 		runtime:  runtime,
 		backOff:  imageBackOff,
+		puller:   puller,
 	}
 }
 
@@ -65,16 +69,16 @@ func shouldPullImage(container *api.Container, imagePresent bool) bool {
 }
 
 // records an event using ref, event msg.  log to glog using prefix, msg, logFn
-func (puller *parallelImagePuller) logIt(ref *api.ObjectReference, eventtype, event, prefix, msg string, logFn func(args ...interface{})) {
+func (m *imageManager) logIt(ref *api.ObjectReference, eventtype, event, prefix, msg string, logFn func(args ...interface{})) {
 	if ref != nil {
-		puller.recorder.Event(ref, eventtype, event, msg)
+		m.recorder.Event(ref, eventtype, event, msg)
 	} else {
 		logFn(fmt.Sprint(prefix, " ", msg))
 	}
 }
 
-// PullImage pulls the image for the specified pod and container.
+// EnsureImageExists pulls the image for the specified pod and container.
-func (puller *parallelImagePuller) pullImage(pod *api.Pod, container *api.Container, pullSecrets []api.Secret) (error, string) {
+func (m *imageManager) EnsureImageExists(pod *api.Pod, container *api.Container, pullSecrets []api.Secret) (error, string) {
 	logPrefix := fmt.Sprintf("%s/%s", pod.Name, container.Image)
 	ref, err := kubecontainer.GenerateContainerRef(pod, container)
 	if err != nil {
@@ -82,35 +86,37 @@ func (puller *parallelImagePuller) pullImage(pod *api.Pod, container *api.Contai
 	}
 
 	spec := kubecontainer.ImageSpec{Image: container.Image}
-	present, err := puller.runtime.IsImagePresent(spec)
+	present, err := m.runtime.IsImagePresent(spec)
 	if err != nil {
 		msg := fmt.Sprintf("Failed to inspect image %q: %v", container.Image, err)
-		puller.logIt(ref, api.EventTypeWarning, events.FailedToInspectImage, logPrefix, msg, glog.Warning)
+		m.logIt(ref, api.EventTypeWarning, events.FailedToInspectImage, logPrefix, msg, glog.Warning)
 		return ErrImageInspect, msg
 	}
 
 	if !shouldPullImage(container, present) {
 		if present {
 			msg := fmt.Sprintf("Container image %q already present on machine", container.Image)
-			puller.logIt(ref, api.EventTypeNormal, events.PulledImage, logPrefix, msg, glog.Info)
+			m.logIt(ref, api.EventTypeNormal, events.PulledImage, logPrefix, msg, glog.Info)
 			return nil, ""
 		} else {
 			msg := fmt.Sprintf("Container image %q is not present with pull policy of Never", container.Image)
-			puller.logIt(ref, api.EventTypeWarning, events.ErrImageNeverPullPolicy, logPrefix, msg, glog.Warning)
+			m.logIt(ref, api.EventTypeWarning, events.ErrImageNeverPullPolicy, logPrefix, msg, glog.Warning)
 			return ErrImageNeverPull, msg
 		}
 	}
 
 	backOffKey := fmt.Sprintf("%s_%s", pod.UID, container.Image)
-	if puller.backOff.IsInBackOffSinceUpdate(backOffKey, puller.backOff.Clock.Now()) {
+	if m.backOff.IsInBackOffSinceUpdate(backOffKey, m.backOff.Clock.Now()) {
 		msg := fmt.Sprintf("Back-off pulling image %q", container.Image)
-		puller.logIt(ref, api.EventTypeNormal, events.BackOffPullImage, logPrefix, msg, glog.Info)
+		m.logIt(ref, api.EventTypeNormal, events.BackOffPullImage, logPrefix, msg, glog.Info)
 		return ErrImagePullBackOff, msg
 	}
-	puller.logIt(ref, api.EventTypeNormal, events.PullingImage, logPrefix, fmt.Sprintf("pulling image %q", container.Image), glog.Info)
+	m.logIt(ref, api.EventTypeNormal, events.PullingImage, logPrefix, fmt.Sprintf("pulling image %q", container.Image), glog.Info)
-	if err := puller.runtime.PullImage(spec, pullSecrets); err != nil {
+	errChan := make(chan error)
-		puller.logIt(ref, api.EventTypeWarning, events.FailedToPullImage, logPrefix, fmt.Sprintf("Failed to pull image %q: %v", container.Image, err), glog.Warning)
+	m.puller.pullImage(spec, pullSecrets, errChan)
-		puller.backOff.Next(backOffKey, puller.backOff.Clock.Now())
+	if err := <-errChan; err != nil {
+		m.logIt(ref, api.EventTypeWarning, events.FailedToPullImage, logPrefix, fmt.Sprintf("Failed to pull image %q: %v", container.Image, err), glog.Warning)
+		m.backOff.Next(backOffKey, m.backOff.Clock.Now())
 		if err == RegistryUnavailable {
 			msg := fmt.Sprintf("image pull failed for %s because the registry is unavailable.", container.Image)
 			return err, msg
@@ -118,7 +124,7 @@ func (puller *parallelImagePuller) pullImage(pod *api.Pod, container *api.Contai
 			return ErrImagePull, err.Error()
 		}
 	}
-	puller.logIt(ref, api.EventTypeNormal, events.PulledImage, logPrefix, fmt.Sprintf("Successfully pulled image %q", container.Image), glog.Info)
+	m.logIt(ref, api.EventTypeNormal, events.PulledImage, logPrefix, fmt.Sprintf("Successfully pulled image %q", container.Image), glog.Info)
-	puller.backOff.GC()
+	m.backOff.GC()
 	return nil, ""
 }

pkg/kubelet/images/image_manager_test.go

@@ -30,6 +30,97 @@ import (
 	"k8s.io/kubernetes/pkg/util/flowcontrol"
 )
 
+func TestParallelPuller(t *testing.T) {
+	pod := &api.Pod{
+		ObjectMeta: api.ObjectMeta{
+			Name:            "test_pod",
+			Namespace:       "test-ns",
+			UID:             "bar",
+			ResourceVersion: "42",
+			SelfLink:        "/api/v1/pods/foo",
+		}}
+
+	cases := []struct {
+		containerImage  string
+		policy          api.PullPolicy
+		calledFunctions []string
+		inspectErr      error
+		pullerErr       error
+		expectedErr     []error
+	}{
+		{ // pull missing image
+			containerImage:  "missing_image",
+			policy:          api.PullIfNotPresent,
+			calledFunctions: []string{"IsImagePresent", "PullImage"},
+			inspectErr:      nil,
+			pullerErr:       nil,
+			expectedErr:     []error{nil}},
+
+		{ // image present, dont pull
+			containerImage:  "present_image",
+			policy:          api.PullIfNotPresent,
+			calledFunctions: []string{"IsImagePresent"},
+			inspectErr:      nil,
+			pullerErr:       nil,
+			expectedErr:     []error{nil, nil, nil}},
+		// image present, pull it
+		{containerImage: "present_image",
+			policy:          api.PullAlways,
+			calledFunctions: []string{"IsImagePresent", "PullImage"},
+			inspectErr:      nil,
+			pullerErr:       nil,
+			expectedErr:     []error{nil, nil, nil}},
+		// missing image, error PullNever
+		{containerImage: "missing_image",
+			policy:          api.PullNever,
+			calledFunctions: []string{"IsImagePresent"},
+			inspectErr:      nil,
+			pullerErr:       nil,
+			expectedErr:     []error{ErrImageNeverPull, ErrImageNeverPull, ErrImageNeverPull}},
+		// missing image, unable to inspect
+		{containerImage: "missing_image",
+			policy:          api.PullIfNotPresent,
+			calledFunctions: []string{"IsImagePresent"},
+			inspectErr:      errors.New("unknown inspectError"),
+			pullerErr:       nil,
+			expectedErr:     []error{ErrImageInspect, ErrImageInspect, ErrImageInspect}},
+		// missing image, unable to fetch
+		{containerImage: "typo_image",
+			policy:          api.PullIfNotPresent,
+			calledFunctions: []string{"IsImagePresent", "PullImage"},
+			inspectErr:      nil,
+			pullerErr:       errors.New("404"),
+			expectedErr:     []error{ErrImagePull, ErrImagePull, ErrImagePullBackOff, ErrImagePull, ErrImagePullBackOff, ErrImagePullBackOff}},
+	}
+
+	for i, c := range cases {
+		container := &api.Container{
+			Name:            "container_name",
+			Image:           c.containerImage,
+			ImagePullPolicy: c.policy,
+		}
+
+		backOff := flowcontrol.NewBackOff(time.Second, time.Minute)
+		fakeClock := clock.NewFakeClock(time.Now())
+		backOff.Clock = fakeClock
+
+		fakeRuntime := &ctest.FakeRuntime{}
+		fakeRecorder := &record.FakeRecorder{}
+		puller := NewImageManager(fakeRecorder, fakeRuntime, backOff, false)
+
+		fakeRuntime.ImageList = []Image{{"present_image", nil, nil, 1}}
+		fakeRuntime.Err = c.pullerErr
+		fakeRuntime.InspectErr = c.inspectErr
+
+		for tick, expected := range c.expectedErr {
+			fakeClock.Step(time.Second)
+			err, _ := puller.EnsureImageExists(pod, container, nil)
+			fakeRuntime.AssertCalls(c.calledFunctions)
+			assert.Equal(t, expected, err, "in test %d tick=%d", i, tick)
+		}
+	}
+}
+
 func TestSerializedPuller(t *testing.T) {
 	pod := &api.Pod{
 		ObjectMeta: api.ObjectMeta{
@@ -106,7 +197,7 @@ func TestSerializedPuller(t *testing.T) {
 
 		fakeRuntime := &ctest.FakeRuntime{}
 		fakeRecorder := &record.FakeRecorder{}
-		puller := newSerializedImagePuller(fakeRecorder, fakeRuntime, backOff)
+		puller := NewImageManager(fakeRecorder, fakeRuntime, backOff, true)
 
 		fakeRuntime.ImageList = []Image{{"present_image", nil, nil, 0}}
 		fakeRuntime.Err = c.pullerErr
@@ -114,10 +205,9 @@ func TestSerializedPuller(t *testing.T) {
 
 		for tick, expected := range c.expectedErr {
 			fakeClock.Step(time.Second)
-			err, _ := puller.pullImage(pod, container, nil)
+			err, _ := puller.EnsureImageExists(pod, container, nil)
 			fakeRuntime.AssertCalls(c.calledFunctions)
 			assert.Equal(t, expected, err, "in test %d tick=%d", i, tick)
 		}
-
 	}
 }

pkg/kubelet/images/impl.go

@@ -1,52 +0,0 @@
-/*
-Copyright 2016 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package images
-
-import (
-	"k8s.io/kubernetes/pkg/api"
-	"k8s.io/kubernetes/pkg/client/record"
-	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
-	"k8s.io/kubernetes/pkg/util/flowcontrol"
-)
-
-type imageManager struct {
-	recorder    record.EventRecorder
-	runtime     kubecontainer.Runtime
-	backOff     *flowcontrol.Backoff
-	imagePuller imagePuller
-}
-
-var _ ImageManager = &imageManager{}
-
-func NewImageManager(recorder record.EventRecorder, runtime kubecontainer.Runtime, imageBackOff *flowcontrol.Backoff, serialized bool) ImageManager {
-	var imagePuller imagePuller
-	if serialized {
-		imagePuller = newSerializedImagePuller(recorder, runtime, imageBackOff)
-	} else {
-		imagePuller = newParallelImagePuller(recorder, runtime, imageBackOff)
-	}
-	return &imageManager{
-		recorder:    recorder,
-		runtime:     runtime,
-		backOff:     imageBackOff,
-		imagePuller: imagePuller,
-	}
-}
-
-func (im *imageManager) EnsureImageExists(pod *api.Pod, container *api.Container, pullSecrets []api.Secret) (error, string) {
-	return im.imagePuller.pullImage(pod, container, pullSecrets)
-}

pkg/kubelet/images/parallel_image_puller_test.go

@@ -1,123 +0,0 @@
-/*
-Copyright 2015 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package images
-
-import (
-	"errors"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"k8s.io/kubernetes/pkg/api"
-	"k8s.io/kubernetes/pkg/client/record"
-	. "k8s.io/kubernetes/pkg/kubelet/container"
-	ctest "k8s.io/kubernetes/pkg/kubelet/container/testing"
-	"k8s.io/kubernetes/pkg/util/clock"
-	"k8s.io/kubernetes/pkg/util/flowcontrol"
-)
-
-func TestPuller(t *testing.T) {
-	pod := &api.Pod{
-		ObjectMeta: api.ObjectMeta{
-			Name:            "test_pod",
-			Namespace:       "test-ns",
-			UID:             "bar",
-			ResourceVersion: "42",
-			SelfLink:        "/api/v1/pods/foo",
-		}}
-
-	cases := []struct {
-		containerImage  string
-		policy          api.PullPolicy
-		calledFunctions []string
-		inspectErr      error
-		pullerErr       error
-		expectedErr     []error
-	}{
-		{ // pull missing image
-			containerImage:  "missing_image",
-			policy:          api.PullIfNotPresent,
-			calledFunctions: []string{"IsImagePresent", "PullImage"},
-			inspectErr:      nil,
-			pullerErr:       nil,
-			expectedErr:     []error{nil}},
-
-		{ // image present, don't pull
-			containerImage:  "present_image",
-			policy:          api.PullIfNotPresent,
-			calledFunctions: []string{"IsImagePresent"},
-			inspectErr:      nil,
-			pullerErr:       nil,
-			expectedErr:     []error{nil, nil, nil}},
-		// image present, pull it
-		{containerImage: "present_image",
-			policy:          api.PullAlways,
-			calledFunctions: []string{"IsImagePresent", "PullImage"},
-			inspectErr:      nil,
-			pullerErr:       nil,
-			expectedErr:     []error{nil, nil, nil}},
-		// missing image, error PullNever
-		{containerImage: "missing_image",
-			policy:          api.PullNever,
-			calledFunctions: []string{"IsImagePresent"},
-			inspectErr:      nil,
-			pullerErr:       nil,
-			expectedErr:     []error{ErrImageNeverPull, ErrImageNeverPull, ErrImageNeverPull}},
-		// missing image, unable to inspect
-		{containerImage: "missing_image",
-			policy:          api.PullIfNotPresent,
-			calledFunctions: []string{"IsImagePresent"},
-			inspectErr:      errors.New("unknown inspectError"),
-			pullerErr:       nil,
-			expectedErr:     []error{ErrImageInspect, ErrImageInspect, ErrImageInspect}},
-		// missing image, unable to fetch
-		{containerImage: "typo_image",
-			policy:          api.PullIfNotPresent,
-			calledFunctions: []string{"IsImagePresent", "PullImage"},
-			inspectErr:      nil,
-			pullerErr:       errors.New("404"),
-			expectedErr:     []error{ErrImagePull, ErrImagePull, ErrImagePullBackOff, ErrImagePull, ErrImagePullBackOff, ErrImagePullBackOff}},
-	}
-
-	for i, c := range cases {
-		container := &api.Container{
-			Name:            "container_name",
-			Image:           c.containerImage,
-			ImagePullPolicy: c.policy,
-		}
-
-		backOff := flowcontrol.NewBackOff(time.Second, time.Minute)
-		fakeClock := clock.NewFakeClock(time.Now())
-		backOff.Clock = fakeClock
-
-		fakeRuntime := &ctest.FakeRuntime{}
-		fakeRecorder := &record.FakeRecorder{}
-		puller := newParallelImagePuller(fakeRecorder, fakeRuntime, backOff)
-
-		fakeRuntime.ImageList = []Image{{"present_image", nil, nil, 1}}
-		fakeRuntime.Err = c.pullerErr
-		fakeRuntime.InspectErr = c.inspectErr
-
-		for tick, expected := range c.expectedErr {
-			fakeClock.Step(time.Second)
-			err, _ := puller.pullImage(pod, container, nil)
-			fakeRuntime.AssertCalls(c.calledFunctions)
-			assert.Equal(t, expected, err, "in test %d tick=%d", i, tick)
-		}
-
-	}
-}

pkg/kubelet/images/puller.go

@@ -0,0 +1,79 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package images
+
+import (
+	"time"
+
+	"k8s.io/kubernetes/pkg/api"
+	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
+	"k8s.io/kubernetes/pkg/util/wait"
+)
+
+type imagePuller interface {
+	pullImage(kubecontainer.ImageSpec, []api.Secret, chan<- error)
+}
+
+var _, _ imagePuller = &parallelImagePuller{}, &serialImagePuller{}
+
+type parallelImagePuller struct {
+	runtime kubecontainer.Runtime
+}
+
+func newParallelImagePuller(runtime kubecontainer.Runtime) imagePuller {
+	return &parallelImagePuller{runtime}
+}
+
+func (pip *parallelImagePuller) pullImage(spec kubecontainer.ImageSpec, pullSecrets []api.Secret, errChan chan<- error) {
+	go func() {
+		errChan <- pip.runtime.PullImage(spec, pullSecrets)
+	}()
+}
+
+// Maximum number of image pull requests than can be queued.
+const maxImagePullRequests = 10
+
+type serialImagePuller struct {
+	runtime      kubecontainer.Runtime
+	pullRequests chan *imagePullRequest
+}
+
+func newSerialImagePuller(runtime kubecontainer.Runtime) imagePuller {
+	imagePuller := &serialImagePuller{runtime, make(chan *imagePullRequest, maxImagePullRequests)}
+	go wait.Until(imagePuller.processImagePullRequests, time.Second, wait.NeverStop)
+	return imagePuller
+}
+
+type imagePullRequest struct {
+	spec        kubecontainer.ImageSpec
+	pullSecrets []api.Secret
+	errChan     chan<- error
+}
+
+func (sip *serialImagePuller) pullImage(spec kubecontainer.ImageSpec, pullSecrets []api.Secret, errChan chan<- error) {
+	sip.pullRequests <- &imagePullRequest{
+		spec:        spec,
+		pullSecrets: pullSecrets,
+		errChan:     errChan,
+	}
+}
+
+func (sip *serialImagePuller) processImagePullRequests() {
+	for pullRequest := range sip.pullRequests {
+		pullRequest.errChan <- sip.runtime.PullImage(pullRequest.spec, pullRequest.pullSecrets)
+	}
+}

pkg/kubelet/images/serialized_image_puller.go

@@ -1,143 +0,0 @@
-/*
-Copyright 2016 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package images
-
-import (
-	"fmt"
-	"time"
-
-	"github.com/golang/glog"
-	"k8s.io/kubernetes/pkg/api"
-	"k8s.io/kubernetes/pkg/client/record"
-	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
-	"k8s.io/kubernetes/pkg/kubelet/events"
-	"k8s.io/kubernetes/pkg/util/flowcontrol"
-	"k8s.io/kubernetes/pkg/util/wait"
-)
-
-type imagePullRequest struct {
-	spec        kubecontainer.ImageSpec
-	container   *api.Container
-	pullSecrets []api.Secret
-	logPrefix   string
-	ref         *api.ObjectReference
-	returnChan  chan<- error
-}
-
-// serializedImagePuller pulls the image using Runtime.PullImage().
-// It will check the presence of the image, and report the 'image pulling',
-// 'image pulled' events correspondingly.
-type serializedImagePuller struct {
-	recorder     record.EventRecorder
-	runtime      kubecontainer.Runtime
-	backOff      *flowcontrol.Backoff
-	pullRequests chan *imagePullRequest
-}
-
-// enforce compatibility.
-var _ imagePuller = &serializedImagePuller{}
-
-// NewSerializedImagePuller takes an event recorder and container runtime to create a
-// image puller that wraps the container runtime's PullImage interface.
-// Pulls one image at a time.
-// Issue #10959 has the rationale behind serializing image pulls.
-func newSerializedImagePuller(recorder record.EventRecorder, runtime kubecontainer.Runtime, imageBackOff *flowcontrol.Backoff) imagePuller {
-	imagePuller := &serializedImagePuller{
-		recorder:     recorder,
-		runtime:      runtime,
-		backOff:      imageBackOff,
-		pullRequests: make(chan *imagePullRequest, 10),
-	}
-	go wait.Until(imagePuller.pullImages, time.Second, wait.NeverStop)
-	return imagePuller
-}
-
-// records an event using ref, event msg.  log to glog using prefix, msg, logFn
-func (puller *serializedImagePuller) logIt(ref *api.ObjectReference, eventtype, event, prefix, msg string, logFn func(args ...interface{})) {
-	if ref != nil {
-		puller.recorder.Event(ref, eventtype, event, msg)
-	} else {
-		logFn(fmt.Sprint(prefix, " ", msg))
-	}
-}
-
-// PullImage pulls the image for the specified pod and container.
-func (puller *serializedImagePuller) pullImage(pod *api.Pod, container *api.Container, pullSecrets []api.Secret) (error, string) {
-	logPrefix := fmt.Sprintf("%s/%s", pod.Name, container.Image)
-	ref, err := kubecontainer.GenerateContainerRef(pod, container)
-	if err != nil {
-		glog.Errorf("Couldn't make a ref to pod %v, container %v: '%v'", pod.Name, container.Name, err)
-	}
-
-	spec := kubecontainer.ImageSpec{Image: container.Image}
-	present, err := puller.runtime.IsImagePresent(spec)
-	if err != nil {
-		msg := fmt.Sprintf("Failed to inspect image %q: %v", container.Image, err)
-		puller.logIt(ref, api.EventTypeWarning, events.FailedToInspectImage, logPrefix, msg, glog.Warning)
-		return ErrImageInspect, msg
-	}
-
-	if !shouldPullImage(container, present) {
-		if present {
-			msg := fmt.Sprintf("Container image %q already present on machine", container.Image)
-			puller.logIt(ref, api.EventTypeNormal, events.PulledImage, logPrefix, msg, glog.Info)
-			return nil, ""
-		} else {
-			msg := fmt.Sprintf("Container image %q is not present with pull policy of Never", container.Image)
-			puller.logIt(ref, api.EventTypeWarning, events.ErrImageNeverPullPolicy, logPrefix, msg, glog.Warning)
-			return ErrImageNeverPull, msg
-		}
-	}
-
-	backOffKey := fmt.Sprintf("%s_%s", pod.UID, container.Image)
-	if puller.backOff.IsInBackOffSinceUpdate(backOffKey, puller.backOff.Clock.Now()) {
-		msg := fmt.Sprintf("Back-off pulling image %q", container.Image)
-		puller.logIt(ref, api.EventTypeNormal, events.BackOffPullImage, logPrefix, msg, glog.Info)
-		return ErrImagePullBackOff, msg
-	}
-
-	// enqueue image pull request and wait for response.
-	returnChan := make(chan error)
-	puller.pullRequests <- &imagePullRequest{
-		spec:        spec,
-		container:   container,
-		pullSecrets: pullSecrets,
-		logPrefix:   logPrefix,
-		ref:         ref,
-		returnChan:  returnChan,
-	}
-	if err = <-returnChan; err != nil {
-		puller.logIt(ref, api.EventTypeWarning, events.FailedToPullImage, logPrefix, fmt.Sprintf("Failed to pull image %q: %v", container.Image, err), glog.Warning)
-		puller.backOff.Next(backOffKey, puller.backOff.Clock.Now())
-		if err == RegistryUnavailable {
-			msg := fmt.Sprintf("image pull failed for %s because the registry is unavailable.", container.Image)
-			return err, msg
-		} else {
-			return ErrImagePull, err.Error()
-		}
-	}
-	puller.logIt(ref, api.EventTypeNormal, events.PulledImage, logPrefix, fmt.Sprintf("Successfully pulled image %q", container.Image), glog.Info)
-	puller.backOff.GC()
-	return nil, ""
-}
-
-func (puller *serializedImagePuller) pullImages() {
-	for pullRequest := range puller.pullRequests {
-		puller.logIt(pullRequest.ref, api.EventTypeNormal, events.PullingImage, pullRequest.logPrefix, fmt.Sprintf("pulling image %q", pullRequest.container.Image), glog.Info)
-		pullRequest.returnChan <- puller.runtime.PullImage(pullRequest.spec, pullRequest.pullSecrets)
-	}
-}

pkg/kubelet/images/types.go

@@ -50,10 +50,3 @@ type ImageManager interface {
 
 	// TODO(ronl): consolidating image managing and deleting operation in this interface
 }
-
-// ImagePuller wraps Runtime.PullImage() to pull a container image.
-// It will check the presence of the image, and report the 'image pulling',
-// 'image pulled' events correspondingly.
-type imagePuller interface {
-	pullImage(pod *api.Pod, container *api.Container, pullSecrets []api.Secret) (error, string)
-}