Merge pull request #995 from csrwng/refactor_api_client

Break up API client into per-resource client and common code

pkg/client/client.go

@@ -34,28 +34,51 @@ import (
 
 // Interface holds the methods for clients of Kubenetes,
 // an interface to allow mock testing.
-// TODO: split this up by resource?
 // TODO: these should return/take pointers.
 type Interface interface {
+	PodInterface
+	ReplicationControllerInterface
+	ServiceInterface
+	VersionInterface
+}
+
+// PodInterface has methods to work with Pod resources
+type PodInterface interface {
 	ListPods(selector labels.Selector) (api.PodList, error)
 	GetPod(name string) (api.Pod, error)
 	DeletePod(name string) error
 	CreatePod(api.Pod) (api.Pod, error)
 	UpdatePod(api.Pod) (api.Pod, error)
+}
 
+// ReplicationControllerInterface has methods to work with ReplicationController resources
+type ReplicationControllerInterface interface {
 	ListReplicationControllers(selector labels.Selector) (api.ReplicationControllerList, error)
 	GetReplicationController(name string) (api.ReplicationController, error)
 	CreateReplicationController(api.ReplicationController) (api.ReplicationController, error)
 	UpdateReplicationController(api.ReplicationController) (api.ReplicationController, error)
 	DeleteReplicationController(string) error
 	WatchReplicationControllers(label, field labels.Selector, resourceVersion uint64) (watch.Interface, error)
+}
 
+// ServiceInterface has methods to work with Service resources
+type ServiceInterface interface {
 	GetService(name string) (api.Service, error)
 	CreateService(api.Service) (api.Service, error)
 	UpdateService(api.Service) (api.Service, error)
 	DeleteService(string) error
 }
 
+// VersionInterface has a method to retrieve the server version
+type VersionInterface interface {
+	ServerVersion() (*version.Info, error)
+}
+
+// Client is the actual implementation of a Kubernetes client.
+type Client struct {
+	*RESTClient
+}
+
 // StatusErr might get returned from an api call if your request is still being processed
 // and hence the expected return data is not available yet.
 type StatusErr struct {
@@ -72,20 +95,23 @@ type AuthInfo struct {
 	Password string
 }
 
-// Client is the actual implementation of a Kubernetes client.
+// RESTClient holds common code used to work with API resources that follow the
+// Kubernetes API pattern
 // Host is the http://... base for the URL
-type Client struct {
+type RESTClient struct {
 	host       string
 	auth       *AuthInfo
 	httpClient *http.Client
 	Sync       bool
 	PollPeriod time.Duration
 	Timeout    time.Duration
+	Prefix     string
 }
 
-// New creates a new client object.
-func New(host string, auth *AuthInfo) *Client {
-	return &Client{
+// NewRESTClient creates a new RESTClient. This client performs generic REST functions
+// such as Get, Put, Post, and Delete on specified paths.
+func NewRESTClient(host string, auth *AuthInfo, prefix string) *RESTClient {
+	return &RESTClient{
 		auth: auth,
 		host: host,
 		httpClient: &http.Client{
@@ -98,11 +124,19 @@ func New(host string, auth *AuthInfo) *Client {
 		Sync:       false,
 		PollPeriod: time.Second * 2,
 		Timeout:    time.Second * 20,
+		Prefix:     prefix,
 	}
+
+}
+
+// New creates a Kubernetes client. This client works with pods, replication controllers
+// and services. It allows operations such as list, get, update and delete on these objects.
+func New(host string, auth *AuthInfo) *Client {
+	return &Client{NewRESTClient(host, auth, "/api/v1beta1/")}
 }
 
 // Execute a request, adds authentication (if auth != nil), and HTTPS cert ignoring.
-func (c *Client) doRequest(request *http.Request) ([]byte, error) {
+func (c *RESTClient) doRequest(request *http.Request) ([]byte, error) {
 	if c.auth != nil {
 		request.SetBasicAuth(c.auth.User, c.auth.Password)
 	}
@@ -148,7 +182,7 @@ func (c *Client) doRequest(request *http.Request) ([]byte, error) {
 // path is the path on the host to hit
 // requestBody is the body of the request. Can be nil.
 // target the interface to marshal the JSON response into.  Can be nil.
-func (c *Client) rawRequest(method, path string, requestBody io.Reader, target interface{}) ([]byte, error) {
+func (c *RESTClient) rawRequest(method, path string, requestBody io.Reader, target interface{}) ([]byte, error) {
 	request, err := http.NewRequest(method, c.makeURL(path), requestBody)
 	if err != nil {
 		return nil, err
@@ -167,8 +201,8 @@ func (c *Client) rawRequest(method, path string, requestBody io.Reader, target i
 	return body, err
 }
 
-func (c *Client) makeURL(path string) string {
-	return c.host + "/api/v1beta1/" + path
+func (c *RESTClient) makeURL(path string) string {
+	return c.host + c.Prefix + path
 }
 
 // ListPods takes a selector, and returns the list of pods that match that selector

pkg/client/client_test.go

@@ -415,7 +415,7 @@ func TestMakeRequest(t *testing.T) {
 		{Request: testRequest{Method: "GET", Path: "/good"}, Response: Response{StatusCode: 200}},
 		{Request: testRequest{Method: "GET", Path: "/bad%ZZ"}, Error: true},
 		{Client: New("", &AuthInfo{"foo", "bar"}), Request: testRequest{Method: "GET", Path: "/auth", Header: "Authorization"}, Response: Response{StatusCode: 200}},
-		{Client: &Client{httpClient: http.DefaultClient}, Request: testRequest{Method: "GET", Path: "/nocertificate"}, Error: true},
+		{Client: &Client{&RESTClient{httpClient: http.DefaultClient}}, Request: testRequest{Method: "GET", Path: "/nocertificate"}, Error: true},
 		{Request: testRequest{Method: "GET", Path: "/error"}, Response: Response{StatusCode: 500}, Error: true},
 		{Request: testRequest{Method: "POST", Path: "/faildecode"}, Response: Response{StatusCode: 200, Body: "aaaaa"}, Target: &struct{}{}, Error: true},
 		{Request: testRequest{Method: "GET", Path: "/failread"}, Response: Response{StatusCode: 200, Body: "aaaaa"}, Target: &struct{}{}, Error: true},

pkg/client/fake.go

@@ -19,6 +19,7 @@ package client
 import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
 )
 
@@ -110,3 +111,9 @@ func (c *Fake) DeleteService(service string) error {
 	c.Actions = append(c.Actions, FakeAction{Action: "delete-service", Value: service})
 	return nil
 }
+
+func (c *Fake) ServerVersion() (*version.Info, error) {
+	c.Actions = append(c.Actions, FakeAction{Action: "get-version", Value: nil})
+	versionInfo := version.Get()
+	return &versionInfo, nil
+}

pkg/client/request.go

@@ -52,11 +52,11 @@ var specialParams = util.NewStringSet("sync", "timeout")
 // if err != nil { ... }
 // list, ok := resp.(*api.PodList)
 //
-func (c *Client) Verb(verb string) *Request {
+func (c *RESTClient) Verb(verb string) *Request {
 	return &Request{
 		verb:       verb,
 		c:          c,
-		path:       "/api/v1beta1",
+		path:       c.Prefix,
 		sync:       c.Sync,
 		timeout:    c.Timeout,
 		params:     map[string]string{},
@@ -65,27 +65,27 @@ func (c *Client) Verb(verb string) *Request {
 }
 
 // Post begins a POST request. Short for c.Verb("POST").
-func (c *Client) Post() *Request {
+func (c *RESTClient) Post() *Request {
 	return c.Verb("POST")
 }
 
 // Put begins a PUT request. Short for c.Verb("PUT").
-func (c *Client) Put() *Request {
+func (c *RESTClient) Put() *Request {
 	return c.Verb("PUT")
 }
 
 // Get begins a GET request. Short for c.Verb("GET").
-func (c *Client) Get() *Request {
+func (c *RESTClient) Get() *Request {
 	return c.Verb("GET")
 }
 
 // Delete begins a DELETE request. Short for c.Verb("DELETE").
-func (c *Client) Delete() *Request {
+func (c *RESTClient) Delete() *Request {
 	return c.Verb("DELETE")
 }
 
 // PollFor makes a request to do a single poll of the completion of the given operation.
-func (c *Client) PollFor(operationID string) *Request {
+func (c *RESTClient) PollFor(operationID string) *Request {
 	return c.Get().Path("operations").Path(operationID).Sync(false).PollPeriod(0)
 }
 
@@ -93,7 +93,7 @@ func (c *Client) PollFor(operationID string) *Request {
 // Any errors are stored until the end of your call, so you only have to
 // check once.
 type Request struct {
-	c          *Client
+	c          *RESTClient
 	err        error
 	verb       string
 	path       string

pkg/kubecfg/kubecfg.go

@@ -36,16 +36,11 @@ import (
 )
 
 func GetServerVersion(client *client.Client) (*version.Info, error) {
-	body, err := client.Get().AbsPath("/version").Do().Raw()
+	info, err := client.ServerVersion()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("Got error: %v", err)
 	}
-	var info version.Info
-	err = json.Unmarshal(body, &info)
-	if err != nil {
-		return nil, fmt.Errorf("Got '%s': %v", string(body), err)
-	}
-	return &info, nil
+	return info, nil
 }
 
 func promptForString(field string, r io.Reader) string {