engine: add inactivity timeout for image pulling

agent/engine/docker_client.go

@@ -83,6 +83,10 @@ const (
 	// around a docker bug which sometimes results in pulls not progressing.
 	dockerPullBeginTimeout = 5 * time.Minute
 
+	// dockerPullInactivityTimeout is the amount of time that we will
+	// wait when the pulling does not progress
+	dockerPullInactivityTimeout = 1 * time.Minute
+
 	// pullStatusSuppressDelay controls the time where pull status progress bar
 	// output will be suppressed in debug mode
 	pullStatusSuppressDelay = 2 * time.Second
@@ -311,6 +315,7 @@ func (dg *dockerGoClient) pullImage(image string, authData *api.RegistryAuthenti
 	opts := docker.PullImageOptions{
 		Repository:   repository,
 		OutputStream: pullWriter,
+		InactivityTimeout: dockerPullInactivityTimeout,
 	}
 	timeout := dg.time().After(dockerPullBeginTimeout)
 	// pullBegan is a channel indicating that we have seen at least one line of data on the 'OutputStream' above.

agent/engine/docker_client_test.go

@@ -167,6 +167,19 @@ func TestPullImageGlobalTimeout(t *testing.T) {
 	wait.Done()
 }
 
+func TestPullImageInactivityTimeout(t *testing.T) {
+	mockDocker, client, testTime, _, _, done := dockerClientSetup(t)
+	defer done()
+
+	testTime.EXPECT().After(gomock.Any()).AnyTimes()
+	mockDocker.EXPECT().PullImage(&pullImageOptsMatcher{"image:latest"}, gomock.Any()).Return(
+		docker.ErrInactivityTimeout).Times(maximumPullRetries) // expected number of retries
+
+	metadata := client.PullImage("image", nil)
+	assert.Error(t, metadata.Error, "Expected error for pull inactivity timeout")
+	assert.Equal(t, "CannotPullContainerError", metadata.Error.(api.NamedError).ErrorName(), "Wrong error type")
+}
+
 func TestPullImage(t *testing.T) {
 	mockDocker, client, testTime, _, _, done := dockerClientSetup(t)
 	defer done()