client: min client for discovery

client/client.go

@@ -0,0 +1,44 @@
+package client
+
+import (
+	"errors"
+	"fmt"
+	"time"
+)
+
+var (
+	ErrUnavailable = errors.New("client: no available etcd endpoints")
+	ErrNoLeader    = errors.New("client: no leader")
+	ErrKeyNoExist  = errors.New("client: key does not exist")
+	ErrKeyExists   = errors.New("client: key already exists")
+)
+
+type Client interface {
+	Create(key, value string, ttl time.Duration) (*Response, error)
+	Get(key string) (*Response, error)
+	Watch(key string) Watcher
+	RecursiveWatch(key string) Watcher
+}
+
+type Watcher interface {
+	Next() (*Response, error)
+}
+
+type Response struct {
+	Action   string `json:"action"`
+	Node     *Node  `json:"node"`
+	PrevNode *Node  `json:"prevNode"`
+}
+
+type Nodes []Node
+type Node struct {
+	Key           string `json:"key"`
+	Value         string `json:"value"`
+	Nodes         Nodes  `json:"nodes"`
+	ModifiedIndex uint64 `json:"modifiedIndex"`
+	CreatedIndex  uint64 `json:"createdIndex"`
+}
+
+func (n *Node) String() string {
+	return fmt.Sprintf("{Key: %s, CreatedIndex: %d, ModifiedIndex: %d}", n.Key, n.CreatedIndex, n.ModifiedIndex)
+}

client/http.go

@@ -0,0 +1,276 @@
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"path"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/coreos/etcd/third_party/code.google.com/p/go.net/context"
+)
+
+const (
+	v2Prefix = "/v2/keys"
+)
+
+// transport mimics http.Transport to provide an interface which can be
+// substituted for testing (since the RoundTripper interface alone does not
+// require the CancelRequest method)
+type transport interface {
+	http.RoundTripper
+	CancelRequest(req *http.Request)
+}
+
+type httpClient struct {
+	transport transport
+	endpoint  url.URL
+	timeout   time.Duration
+}
+
+func NewHTTPClient(tr *http.Transport, ep string, timeout time.Duration) (*httpClient, error) {
+	u, err := url.Parse(ep)
+	if err != nil {
+		return nil, err
+	}
+
+	c := &httpClient{
+		transport: tr,
+		endpoint:  *u,
+		timeout:   timeout,
+	}
+
+	return c, nil
+}
+
+func (c *httpClient) Create(key, val string, ttl time.Duration) (*Response, error) {
+	uintTTL := uint64(ttl.Seconds())
+	create := &createAction{
+		Key:   key,
+		Value: val,
+		TTL:   &uintTTL,
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), c.timeout)
+	httpresp, body, err := c.do(ctx, create)
+	cancel()
+
+	if err != nil {
+		return nil, err
+	}
+
+	return unmarshalHTTPResponse(httpresp.StatusCode, body)
+}
+
+func (c *httpClient) Get(key string) (*Response, error) {
+	get := &getAction{
+		Key:       key,
+		Recursive: false,
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), c.timeout)
+	httpresp, body, err := c.do(ctx, get)
+	cancel()
+
+	if err != nil {
+		return nil, err
+	}
+
+	return unmarshalHTTPResponse(httpresp.StatusCode, body)
+}
+
+type roundTripResponse struct {
+	resp *http.Response
+	err  error
+}
+
+func (c *httpClient) do(ctx context.Context, act httpAction) (*http.Response, []byte, error) {
+	req := act.httpRequest(c.endpoint)
+
+	rtchan := make(chan roundTripResponse, 1)
+	go func() {
+		resp, err := c.transport.RoundTrip(req)
+		rtchan <- roundTripResponse{resp: resp, err: err}
+		close(rtchan)
+	}()
+
+	var resp *http.Response
+	var err error
+
+	select {
+	case rtresp := <-rtchan:
+		resp, err = rtresp.resp, rtresp.err
+	case <-ctx.Done():
+		c.transport.CancelRequest(req)
+		// wait for request to actually exit before continuing
+		<-rtchan
+		err = ctx.Err()
+	}
+
+	// always check for resp nil-ness to deal with possible
+	// race conditions between channels above
+	defer func() {
+		if resp != nil {
+			resp.Body.Close()
+		}
+	}()
+
+	if err != nil {
+		return nil, nil, err
+	}
+
+	body, err := ioutil.ReadAll(resp.Body)
+	return resp, body, err
+}
+
+func (c *httpClient) Watch(key string, idx uint64) *httpWatcher {
+	return &httpWatcher{
+		httpClient: *c,
+		nextWait: waitAction{
+			Key:       key,
+			WaitIndex: idx,
+			Recursive: false,
+		},
+	}
+}
+
+func (c *httpClient) RecursiveWatch(key string, idx uint64) *httpWatcher {
+	return &httpWatcher{
+		httpClient: *c,
+		nextWait: waitAction{
+			Key:       key,
+			WaitIndex: idx,
+			Recursive: true,
+		},
+	}
+}
+
+type httpWatcher struct {
+	httpClient
+	nextWait waitAction
+}
+
+func (hw *httpWatcher) Next() (*Response, error) {
+	httpresp, body, err := hw.httpClient.do(context.Background(), &hw.nextWait)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := unmarshalHTTPResponse(httpresp.StatusCode, body)
+	if err != nil {
+		return nil, err
+	}
+
+	hw.nextWait.WaitIndex = resp.Node.ModifiedIndex + 1
+	return resp, nil
+}
+
+func v2URL(ep url.URL, key string) *url.URL {
+	ep.Path = path.Join(ep.Path, v2Prefix, key)
+	return &ep
+}
+
+type httpAction interface {
+	httpRequest(url.URL) *http.Request
+}
+
+type getAction struct {
+	Key       string
+	Recursive bool
+}
+
+func (g *getAction) httpRequest(ep url.URL) *http.Request {
+	u := v2URL(ep, g.Key)
+
+	params := u.Query()
+	params.Set("recursive", strconv.FormatBool(g.Recursive))
+	u.RawQuery = params.Encode()
+
+	req, _ := http.NewRequest("GET", u.String(), nil)
+	return req
+}
+
+type waitAction struct {
+	Key       string
+	WaitIndex uint64
+	Recursive bool
+}
+
+func (w *waitAction) httpRequest(ep url.URL) *http.Request {
+	u := v2URL(ep, w.Key)
+
+	params := u.Query()
+	params.Set("wait", "true")
+	params.Set("waitIndex", strconv.FormatUint(w.WaitIndex, 10))
+	params.Set("recursive", strconv.FormatBool(w.Recursive))
+	u.RawQuery = params.Encode()
+
+	req, _ := http.NewRequest("GET", u.String(), nil)
+	return req
+}
+
+type createAction struct {
+	Key   string
+	Value string
+	TTL   *uint64
+}
+
+func (c *createAction) httpRequest(ep url.URL) *http.Request {
+	u := v2URL(ep, c.Key)
+
+	params := u.Query()
+	params.Set("prevExist", "false")
+	u.RawQuery = params.Encode()
+
+	form := url.Values{}
+	form.Add("value", c.Value)
+	if c.TTL != nil {
+		form.Add("ttl", strconv.FormatUint(*c.TTL, 10))
+	}
+	body := strings.NewReader(form.Encode())
+
+	req, _ := http.NewRequest("PUT", u.String(), body)
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	return req
+}
+
+func unmarshalHTTPResponse(code int, body []byte) (res *Response, err error) {
+	switch code {
+	case http.StatusOK, http.StatusCreated:
+		res, err = unmarshalSuccessfulResponse(body)
+	default:
+		err = unmarshalErrorResponse(code)
+	}
+
+	return
+}
+
+func unmarshalSuccessfulResponse(body []byte) (*Response, error) {
+	var res Response
+	err := json.Unmarshal(body, &res)
+	if err != nil {
+		return nil, err
+	}
+
+	return &res, nil
+}
+
+func unmarshalErrorResponse(code int) error {
+	switch code {
+	case http.StatusNotFound:
+		return ErrKeyNoExist
+	case http.StatusPreconditionFailed:
+		return ErrKeyExists
+	case http.StatusInternalServerError:
+		// this isn't necessarily true
+		return ErrNoLeader
+	default:
+	}
+
+	return fmt.Errorf("unrecognized HTTP status code %d", code)
+}

client/http_test.go

@@ -0,0 +1,464 @@
+package client
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/coreos/etcd/third_party/code.google.com/p/go.net/context"
+)
+
+func TestV2URLHelper(t *testing.T) {
+	tests := []struct {
+		endpoint url.URL
+		key      string
+		want     url.URL
+	}{
+		// key is empty, no problem
+		{
+			endpoint: url.URL{Scheme: "http", Host: "example.com", Path: ""},
+			key:      "",
+			want:     url.URL{Scheme: "http", Host: "example.com", Path: "/v2/keys"},
+		},
+
+		// key is joined to path
+		{
+			endpoint: url.URL{Scheme: "http", Host: "example.com", Path: ""},
+			key:      "/foo/bar",
+			want:     url.URL{Scheme: "http", Host: "example.com", Path: "/v2/keys/foo/bar"},
+		},
+
+		// Host field carries through with port
+		{
+			endpoint: url.URL{Scheme: "http", Host: "example.com:8080", Path: ""},
+			key:      "",
+			want:     url.URL{Scheme: "http", Host: "example.com:8080", Path: "/v2/keys"},
+		},
+
+		// Scheme carries through
+		{
+			endpoint: url.URL{Scheme: "https", Host: "example.com", Path: ""},
+			key:      "",
+			want:     url.URL{Scheme: "https", Host: "example.com", Path: "/v2/keys"},
+		},
+
+		// Path on endpoint is not ignored
+		{
+			endpoint: url.URL{Scheme: "https", Host: "example.com", Path: "/prefix"},
+			key:      "/foo",
+			want:     url.URL{Scheme: "https", Host: "example.com", Path: "/prefix/v2/keys/foo"},
+		},
+	}
+
+	for i, tt := range tests {
+		got := v2URL(tt.endpoint, tt.key)
+		if tt.want != *got {
+			t.Errorf("#%d: want=%#v, got=%#v", i, tt.want, *got)
+		}
+	}
+}
+
+func TestGetAction(t *testing.T) {
+	ep := url.URL{Scheme: "http", Host: "example.com"}
+	wantURL := &url.URL{
+		Scheme: "http",
+		Host:   "example.com",
+		Path:   "/v2/keys/foo/bar",
+	}
+	wantHeader := http.Header{}
+
+	tests := []struct {
+		recursive bool
+		wantQuery string
+	}{
+		{
+			recursive: false,
+			wantQuery: "recursive=false",
+		},
+		{
+			recursive: true,
+			wantQuery: "recursive=true",
+		},
+	}
+
+	for i, tt := range tests {
+		f := getAction{
+			Key:       "/foo/bar",
+			Recursive: tt.recursive,
+		}
+		got := *f.httpRequest(ep)
+
+		wantURL := wantURL
+		wantURL.RawQuery = tt.wantQuery
+
+		err := assertResponse(got, wantURL, wantHeader, nil)
+		if err != nil {
+			t.Errorf("%#d: %v", i, err)
+		}
+	}
+}
+
+func TestWaitAction(t *testing.T) {
+	ep := url.URL{Scheme: "http", Host: "example.com"}
+	wantURL := &url.URL{
+		Scheme: "http",
+		Host:   "example.com",
+		Path:   "/v2/keys/foo/bar",
+	}
+	wantHeader := http.Header{}
+
+	tests := []struct {
+		waitIndex uint64
+		recursive bool
+		wantQuery string
+	}{
+		{
+			recursive: false,
+			waitIndex: uint64(0),
+			wantQuery: "recursive=false&wait=true&waitIndex=0",
+		},
+		{
+			recursive: false,
+			waitIndex: uint64(12),
+			wantQuery: "recursive=false&wait=true&waitIndex=12",
+		},
+		{
+			recursive: true,
+			waitIndex: uint64(12),
+			wantQuery: "recursive=true&wait=true&waitIndex=12",
+		},
+	}
+
+	for i, tt := range tests {
+		f := waitAction{
+			Key:       "/foo/bar",
+			WaitIndex: tt.waitIndex,
+			Recursive: tt.recursive,
+		}
+		got := *f.httpRequest(ep)
+
+		wantURL := wantURL
+		wantURL.RawQuery = tt.wantQuery
+
+		err := assertResponse(got, wantURL, wantHeader, nil)
+		if err != nil {
+			t.Errorf("%#d: %v", i, err)
+		}
+	}
+}
+
+func TestCreateAction(t *testing.T) {
+	ep := url.URL{Scheme: "http", Host: "example.com"}
+	wantURL := &url.URL{
+		Scheme:   "http",
+		Host:     "example.com",
+		Path:     "/v2/keys/foo/bar",
+		RawQuery: "prevExist=false",
+	}
+	wantHeader := http.Header(map[string][]string{
+		"Content-Type": []string{"application/x-www-form-urlencoded"},
+	})
+
+	ttl12 := uint64(12)
+	tests := []struct {
+		value    string
+		ttl      *uint64
+		wantBody string
+	}{
+		{
+			value:    "baz",
+			wantBody: "value=baz",
+		},
+		{
+			value:    "baz",
+			ttl:      &ttl12,
+			wantBody: "ttl=12&value=baz",
+		},
+	}
+
+	for i, tt := range tests {
+		f := createAction{
+			Key:   "/foo/bar",
+			Value: tt.value,
+			TTL:   tt.ttl,
+		}
+		got := *f.httpRequest(ep)
+
+		err := assertResponse(got, wantURL, wantHeader, []byte(tt.wantBody))
+		if err != nil {
+			t.Errorf("%#d: %v", i, err)
+		}
+	}
+}
+
+func assertResponse(got http.Request, wantURL *url.URL, wantHeader http.Header, wantBody []byte) error {
+	if !reflect.DeepEqual(wantURL, got.URL) {
+		return fmt.Errorf("want.URL=%#v got.URL=%#v", wantURL, got.URL)
+	}
+
+	if !reflect.DeepEqual(wantHeader, got.Header) {
+		return fmt.Errorf("want.Header=%#v got.Header=%#v", wantHeader, got.Header)
+	}
+
+	if got.Body == nil {
+		if wantBody != nil {
+			return fmt.Errorf("want.Body=%v got.Body=%v", wantBody, got.Body)
+		}
+	} else {
+		if wantBody == nil {
+			return fmt.Errorf("want.Body=%v got.Body=%v", wantBody, got.Body)
+		} else {
+			gotBytes, err := ioutil.ReadAll(got.Body)
+			if err != nil {
+				return err
+			}
+
+			if !reflect.DeepEqual(wantBody, gotBytes) {
+				return fmt.Errorf("want.Body=%v got.Body=%v", wantBody, gotBytes)
+			}
+		}
+	}
+
+	return nil
+}
+
+func TestUnmarshalSuccessfulResponse(t *testing.T) {
+	tests := []struct {
+		body        string
+		res         *Response
+		expectError bool
+	}{
+		// Neither PrevNode or Node
+		{
+			`{"action":"delete"}`,
+			&Response{Action: "delete"},
+			false,
+		},
+
+		// PrevNode
+		{
+			`{"action":"delete", "prevNode": {"key": "/foo", "value": "bar", "modifiedIndex": 12, "createdIndex": 10}}`,
+			&Response{Action: "delete", PrevNode: &Node{Key: "/foo", Value: "bar", ModifiedIndex: 12, CreatedIndex: 10}},
+			false,
+		},
+
+		// Node
+		{
+			`{"action":"get", "node": {"key": "/foo", "value": "bar", "modifiedIndex": 12, "createdIndex": 10}}`,
+			&Response{Action: "get", Node: &Node{Key: "/foo", Value: "bar", ModifiedIndex: 12, CreatedIndex: 10}},
+			false,
+		},
+
+		// PrevNode and Node
+		{
+			`{"action":"update", "prevNode": {"key": "/foo", "value": "baz", "modifiedIndex": 10, "createdIndex": 10}, "node": {"key": "/foo", "value": "bar", "modifiedIndex": 12, "createdIndex": 10}}`,
+			&Response{Action: "update", PrevNode: &Node{Key: "/foo", Value: "baz", ModifiedIndex: 10, CreatedIndex: 10}, Node: &Node{Key: "/foo", Value: "bar", ModifiedIndex: 12, CreatedIndex: 10}},
+			false,
+		},
+
+		// Garbage in body
+		{
+			`garbage`,
+			nil,
+			true,
+		},
+	}
+
+	for i, tt := range tests {
+		res, err := unmarshalSuccessfulResponse([]byte(tt.body))
+		if tt.expectError != (err != nil) {
+			t.Errorf("#%d: expectError=%t, err=%v", i, tt.expectError, err)
+		}
+
+		if (res == nil) != (tt.res == nil) {
+			t.Errorf("#%d: received res==%v, but expected res==%v", i, res, tt.res)
+			continue
+		} else if tt.res == nil {
+			// expected and succesfully got nil response
+			continue
+		}
+
+		if res.Action != tt.res.Action {
+			t.Errorf("#%d: Action=%s, expected %s", i, res.Action, tt.res.Action)
+		}
+
+		if !reflect.DeepEqual(res.Node, tt.res.Node) {
+			t.Errorf("#%d: Node=%v, expected %v", i, res.Node, tt.res.Node)
+		}
+	}
+}
+
+func TestUnmarshalErrorResponse(t *testing.T) {
+	unrecognized := errors.New("test fixture")
+
+	tests := []struct {
+		code int
+		want error
+	}{
+		{http.StatusBadRequest, unrecognized},
+		{http.StatusUnauthorized, unrecognized},
+		{http.StatusPaymentRequired, unrecognized},
+		{http.StatusForbidden, unrecognized},
+		{http.StatusNotFound, ErrKeyNoExist},
+		{http.StatusMethodNotAllowed, unrecognized},
+		{http.StatusNotAcceptable, unrecognized},
+		{http.StatusProxyAuthRequired, unrecognized},
+		{http.StatusRequestTimeout, unrecognized},
+		{http.StatusConflict, unrecognized},
+		{http.StatusGone, unrecognized},
+		{http.StatusLengthRequired, unrecognized},
+		{http.StatusPreconditionFailed, ErrKeyExists},
+		{http.StatusRequestEntityTooLarge, unrecognized},
+		{http.StatusRequestURITooLong, unrecognized},
+		{http.StatusUnsupportedMediaType, unrecognized},
+		{http.StatusRequestedRangeNotSatisfiable, unrecognized},
+		{http.StatusExpectationFailed, unrecognized},
+		{http.StatusTeapot, unrecognized},
+
+		{http.StatusInternalServerError, ErrNoLeader},
+		{http.StatusNotImplemented, unrecognized},
+		{http.StatusBadGateway, unrecognized},
+		{http.StatusServiceUnavailable, unrecognized},
+		{http.StatusGatewayTimeout, unrecognized},
+		{http.StatusHTTPVersionNotSupported, unrecognized},
+	}
+
+	for i, tt := range tests {
+		want := tt.want
+		if reflect.DeepEqual(unrecognized, want) {
+			want = fmt.Errorf("unrecognized HTTP status code %d", tt.code)
+		}
+
+		got := unmarshalErrorResponse(tt.code)
+		if !reflect.DeepEqual(want, got) {
+			t.Errorf("#%d: want=%v, got=%v", i, want, got)
+		}
+	}
+}
+
+type fakeTransport struct {
+	respchan     chan *http.Response
+	errchan      chan error
+	startCancel  chan struct{}
+	finishCancel chan struct{}
+}
+
+func newFakeTransport() *fakeTransport {
+	return &fakeTransport{
+		respchan:     make(chan *http.Response, 1),
+		errchan:      make(chan error, 1),
+		startCancel:  make(chan struct{}, 1),
+		finishCancel: make(chan struct{}, 1),
+	}
+}
+
+func (t *fakeTransport) RoundTrip(*http.Request) (*http.Response, error) {
+	select {
+	case resp := <-t.respchan:
+		return resp, nil
+	case err := <-t.errchan:
+		return nil, err
+	case <-t.startCancel:
+		// wait on finishCancel to simulate taking some amount of
+		// time while calling CancelRequest
+		<-t.finishCancel
+		return nil, errors.New("cancelled")
+	}
+}
+
+func (t *fakeTransport) CancelRequest(*http.Request) {
+	t.startCancel <- struct{}{}
+}
+
+type fakeAction struct{}
+
+func (a *fakeAction) httpRequest(url.URL) *http.Request {
+	return &http.Request{}
+}
+
+func TestHTTPClientDoSuccess(t *testing.T) {
+	tr := newFakeTransport()
+	c := &httpClient{transport: tr}
+
+	tr.respchan <- &http.Response{
+		StatusCode: http.StatusTeapot,
+		Body:       ioutil.NopCloser(strings.NewReader("foo")),
+	}
+
+	resp, body, err := c.do(context.Background(), &fakeAction{})
+	if err != nil {
+		t.Fatalf("incorrect error value: want=nil got=%v", err)
+	}
+
+	wantCode := http.StatusTeapot
+	if wantCode != resp.StatusCode {
+		t.Fatalf("invalid response code: want=%d got=%d", wantCode, resp.StatusCode)
+	}
+
+	wantBody := []byte("foo")
+	if !reflect.DeepEqual(wantBody, body) {
+		t.Fatalf("invalid response body: want=%q got=%q", wantBody, body)
+	}
+}
+
+func TestHTTPClientDoError(t *testing.T) {
+	tr := newFakeTransport()
+	c := &httpClient{transport: tr}
+
+	tr.errchan <- errors.New("fixture")
+
+	_, _, err := c.do(context.Background(), &fakeAction{})
+	if err == nil {
+		t.Fatalf("expected non-nil error, got nil")
+	}
+}
+
+func TestHTTPClientDoCancelContext(t *testing.T) {
+	tr := newFakeTransport()
+	c := &httpClient{transport: tr}
+
+	tr.startCancel <- struct{}{}
+	tr.finishCancel <- struct{}{}
+
+	_, _, err := c.do(context.Background(), &fakeAction{})
+	if err == nil {
+		t.Fatalf("expected non-nil error, got nil")
+	}
+}
+
+func TestHTTPClientDoCancelContextWaitForRoundTrip(t *testing.T) {
+	tr := newFakeTransport()
+	c := &httpClient{transport: tr}
+
+	donechan := make(chan struct{})
+	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		c.do(ctx, &fakeAction{})
+		close(donechan)
+	}()
+
+	// This should call CancelRequest and begin the cancellation process
+	cancel()
+
+	select {
+	case <-donechan:
+		t.Fatalf("httpClient.do should not have exited yet")
+	default:
+	}
+
+	tr.finishCancel <- struct{}{}
+
+	select {
+	case <-donechan:
+		//expected behavior
+		return
+	case <-time.After(time.Second):
+		t.Fatalf("httpClient.do did not exit within 1s")
+	}
+}

test

@@ -14,7 +14,7 @@ COVER=${COVER:-"-cover"}
 
 source ./build
 
-TESTABLE="etcdserver etcdserver/etcdhttp etcdserver/etcdserverpb functional proxy raft snap store wait wal ./"
+TESTABLE="client etcdserver etcdserver/etcdhttp etcdserver/etcdserverpb functional proxy raft snap store wait wal ./"
 FORMATTABLE="$TESTABLE cors.go"
 
 # user has not provided PKG override