Move Docker specific function out of the Kubelet

pkg/kubelet/docker.go

+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 kubelet
+
+import (
+	"fmt"
+	"math/rand"
+	"strings"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/fsouza/go-dockerclient"
+)
+
+// DockerContainerData is the structured representation of the JSON object returned by Docker inspect
+type DockerContainerData struct {
+	state struct {
+		Running bool
+	}
+}
+
+// DockerInterface is an abstract interface for testability.  It abstracts the interface of docker.Client.
+type DockerInterface interface {
+	ListContainers(options docker.ListContainersOptions) ([]docker.APIContainers, error)
+	InspectContainer(id string) (*docker.Container, error)
+	CreateContainer(docker.CreateContainerOptions) (*docker.Container, error)
+	StartContainer(id string, hostConfig *docker.HostConfig) error
+	StopContainer(id string, timeout uint) error
+	PullImage(opts docker.PullImageOptions, auth docker.AuthConfiguration) error
+}
+
+// DockerID is an ID of docker container. It is a type to make it clear when we're working with docker container Ids
+type DockerID string
+
+// DockerPuller is an abstract interface for testability.  It abstracts image pull operations.
+type DockerPuller interface {
+	Pull(image string) error
+}
+
+// dockerPuller is the default implementation of DockerPuller.
+type dockerPuller struct {
+	client DockerInterface
+}
+
+// NewDockerPuller creates a new instance of the default implementation of DockerPuller.
+func NewDockerPuller(client DockerInterface) DockerPuller {
+	return dockerPuller{
+		client: client,
+	}
+}
+
+func (p dockerPuller) Pull(image string) error {
+	image, tag := parseImageName(image)
+	opts := docker.PullImageOptions{
+		Repository: image,
+		Tag:        tag,
+	}
+	return p.client.PullImage(opts, docker.AuthConfiguration{})
+}
+
+// Converts "-" to "_-_" and "_" to "___" so that we can use "--" to meaningfully separate parts of a docker name.
+func escapeDash(in string) (out string) {
+	out = strings.Replace(in, "_", "___", -1)
+	out = strings.Replace(out, "-", "_-_", -1)
+	return
+}
+
+// Reverses the transformation of escapeDash.
+func unescapeDash(in string) (out string) {
+	out = strings.Replace(in, "_-_", "-", -1)
+	out = strings.Replace(out, "___", "_", -1)
+	return
+}
+
+const containerNamePrefix = "k8s"
+
+// Creates a name which can be reversed to identify both manifest id and container name.
+func buildDockerName(manifest *api.ContainerManifest, container *api.Container) string {
+	// Note, manifest.ID could be blank.
+	return fmt.Sprintf("%s--%s--%s--%08x", containerNamePrefix, escapeDash(container.Name), escapeDash(manifest.ID), rand.Uint32())
+}
+
+// Upacks a container name, returning the manifest id and container name we would have used to
+// construct the docker name. If the docker name isn't one we created, we may return empty strings.
+func parseDockerName(name string) (manifestID, containerName string) {
+	// For some reason docker appears to be appending '/' to names.
+	// If its there, strip it.
+	if name[0] == '/' {
+		name = name[1:]
+	}
+	parts := strings.Split(name, "--")
+	if len(parts) == 0 || parts[0] != containerNamePrefix {
+		return
+	}
+	if len(parts) > 1 {
+		containerName = unescapeDash(parts[1])
+	}
+	if len(parts) > 2 {
+		manifestID = unescapeDash(parts[2])
+	}
+	return
+}
+
+// Parses image name including an tag and returns image name and tag
+// TODO: Future Docker versions can parse the tag on daemon side, see:
+// https://github.com/dotcloud/docker/issues/6876
+// So this can be deprecated at some point.
+func parseImageName(image string) (string, string) {
+	tag := ""
+	parts := strings.SplitN(image, "/", 2)
+	repo := ""
+	if len(parts) == 2 {
+		repo = parts[0]
+		image = parts[1]
+	}
+	parts = strings.SplitN(image, ":", 2)
+	if len(parts) == 2 {
+		image = parts[0]
+		tag = parts[1]
+	}
+	if repo != "" {
+		image = fmt.Sprintf("%s/%s", repo, image)
+	}
+	return image, tag
+}

pkg/kubelet/kubelet.go

@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
-	"math/rand"
 	"net"
 	"net/http"
 	"os"
@@ -47,31 +46,6 @@ import (
 
 const defaultChanSize = 1024
 
-// DockerContainerData is the structured representation of the JSON object returned by Docker inspect
-type DockerContainerData struct {
-	state struct {
-		Running bool
-	}
-}
-
-// DockerInterface is an abstract interface for testability.  It abstracts the interface of docker.Client.
-type DockerInterface interface {
-	ListContainers(options docker.ListContainersOptions) ([]docker.APIContainers, error)
-	InspectContainer(id string) (*docker.Container, error)
-	CreateContainer(docker.CreateContainerOptions) (*docker.Container, error)
-	StartContainer(id string, hostConfig *docker.HostConfig) error
-	StopContainer(id string, timeout uint) error
-	PullImage(opts docker.PullImageOptions, auth docker.AuthConfiguration) error
-}
-
-// DockerID is an ID of docker container. It is a type to make it clear when we're working with docker container Ids
-type DockerID string
-
-// DockerPuller is an abstract interface for testability.  It abstracts image pull operations.
-type DockerPuller interface {
-	Pull(image string) error
-}
-
 // CadvisorInterface is an abstract interface for testability.  It abstracts the interface of "github.com/google/cadvisor/client".Client.
 type CadvisorInterface interface {
 	ContainerInfo(name string) (*info.ContainerInfo, error)
@@ -120,7 +94,7 @@ func (kl *Kubelet) RunKubelet(dockerEndpoint, configPath, manifestURL, etcdServe
 		}
 	}
 	if kl.DockerPuller == nil {
-		kl.DockerPuller = kl.MakeDockerPuller()
+		kl.DockerPuller = NewDockerPuller(kl.DockerClient)
 	}
 	updateChannel := make(chan manifestUpdate)
 	if configPath != "" {
@@ -237,70 +211,6 @@ func (kl *Kubelet) getContainer(ID DockerID) (*docker.APIContainers, error) {
 	return nil, nil
 }
 
-// MakeDockerPuller creates a new instance of the default implementation of DockerPuller.
-func (kl *Kubelet) MakeDockerPuller() DockerPuller {
-	return dockerPuller{
-		client: kl.DockerClient,
-	}
-}
-
-// dockerPuller is the default implementation of DockerPuller.
-type dockerPuller struct {
-	client DockerInterface
-}
-
-func (p dockerPuller) Pull(image string) error {
-	image, tag := parseImageName(image)
-	opts := docker.PullImageOptions{
-		Repository: image,
-		Tag:        tag,
-	}
-	return p.client.PullImage(opts, docker.AuthConfiguration{})
-}
-
-// Converts "-" to "_-_" and "_" to "___" so that we can use "--" to meaningfully separate parts of a docker name.
-func escapeDash(in string) (out string) {
-	out = strings.Replace(in, "_", "___", -1)
-	out = strings.Replace(out, "-", "_-_", -1)
-	return
-}
-
-// Reverses the transformation of escapeDash.
-func unescapeDash(in string) (out string) {
-	out = strings.Replace(in, "_-_", "-", -1)
-	out = strings.Replace(out, "___", "_", -1)
-	return
-}
-
-const containerNamePrefix = "k8s"
-
-// Creates a name which can be reversed to identify both manifest id and container name.
-func buildDockerName(manifest *api.ContainerManifest, container *api.Container) string {
-	// Note, manifest.ID could be blank.
-	return fmt.Sprintf("%s--%s--%s--%08x", containerNamePrefix, escapeDash(container.Name), escapeDash(manifest.ID), rand.Uint32())
-}
-
-// Upacks a container name, returning the manifest id and container name we would have used to
-// construct the docker name. If the docker name isn't one we created, we may return empty strings.
-func parseDockerName(name string) (manifestID, containerName string) {
-	// For some reason docker appears to be appending '/' to names.
-	// If its there, strip it.
-	if name[0] == '/' {
-		name = name[1:]
-	}
-	parts := strings.Split(name, "--")
-	if len(parts) == 0 || parts[0] != containerNamePrefix {
-		return
-	}
-	if len(parts) > 1 {
-		containerName = unescapeDash(parts[1])
-	}
-	if len(parts) > 2 {
-		manifestID = unescapeDash(parts[2])
-	}
-	return
-}
-
 func makeEnvironmentVariables(container *api.Container) []string {
 	var result []string
 	for _, value := range container.Env {
@@ -359,29 +269,6 @@ func makePortsAndBindings(container *api.Container) (map[docker.Port]struct{}, m
 	return exposedPorts, portBindings
 }
 
-// Parses image name including an tag and returns image name and tag
-// TODO: Future Docker versions can parse the tag on daemon side, see:
-// https://github.com/dotcloud/docker/issues/6876
-// So this can be deprecated at some point.
-func parseImageName(image string) (string, string) {
-	tag := ""
-	parts := strings.SplitN(image, "/", 2)
-	repo := ""
-	if len(parts) == 2 {
-		repo = parts[0]
-		image = parts[1]
-	}
-	parts = strings.SplitN(image, ":", 2)
-	if len(parts) == 2 {
-		image = parts[0]
-		tag = parts[1]
-	}
-	if repo != "" {
-		image = fmt.Sprintf("%s/%s", repo, image)
-	}
-	return image, tag
-}
-
 // Run a single container from a manifest. Returns the docker container ID
 func (kl *Kubelet) runContainer(manifest *api.ContainerManifest, container *api.Container, netMode string) (id DockerID, err error) {
 	envVariables := makeEnvironmentVariables(container)