etcdhttp: add /version endpoint

etcdserver/etcdhttp/http.go

@@ -37,6 +37,7 @@ import (
 	"github.com/coreos/etcd/pkg/types"
 	"github.com/coreos/etcd/raft/raftpb"
 	"github.com/coreos/etcd/store"
+	"github.com/coreos/etcd/version"
 )
 
 const (
@@ -45,6 +46,7 @@ const (
 	deprecatedMachinesPrefix = "/v2/machines"
 	adminMembersPrefix       = "/v2/admin/members/"
 	statsPrefix              = "/v2/stats"
+	versionPrefix            = "/version"
 	// prefixes of peer endpoint
 	raftPrefix    = "/raft"
 	membersPrefix = "/members"
@@ -74,11 +76,9 @@ func NewClientHandler(server *etcdserver.EtcdServer) http.Handler {
 	mux.HandleFunc(statsPrefix+"/store", sh.serveStoreStats)
 	mux.HandleFunc(statsPrefix+"/self", sh.serveSelfStats)
 	mux.HandleFunc(statsPrefix+"/leader", sh.serveLeaderStats)
-	// TODO: dynamic configuration may make this outdated. take care of it.
-	// TODO: dynamic configuration may introduce race also.
-	// TODO: add serveMembers
 	mux.HandleFunc(deprecatedMachinesPrefix, sh.serveMachines)
 	mux.HandleFunc(adminMembersPrefix, sh.serveAdminMembers)
+	mux.HandleFunc(versionPrefix, sh.serveVersion)
 	mux.HandleFunc("/", http.NotFound)
 	return mux
 }
@@ -249,6 +249,13 @@ func (h serverHandler) serveLeaderStats(w http.ResponseWriter, r *http.Request)
 	w.Write(h.stats.LeaderStats())
 }
 
+func (h serverHandler) serveVersion(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET") {
+		return
+	}
+	w.Write([]byte("etcd " + version.Version))
+}
+
 func (h serverHandler) serveRaft(w http.ResponseWriter, r *http.Request) {
 	if !allowMethod(w, r.Method, "POST") {
 		return

etcdserver/etcdhttp/http_test.go

@@ -20,6 +20,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -40,6 +41,7 @@ import (
 	"github.com/coreos/etcd/etcdserver/etcdserverpb"
 	"github.com/coreos/etcd/raft/raftpb"
 	"github.com/coreos/etcd/store"
+	"github.com/coreos/etcd/version"
 )
 
 func boolp(b bool) *bool { return &b }
@@ -754,6 +756,40 @@ func TestServeStoreStats(t *testing.T) {
 
 }
 
+func TestServeVersion(t *testing.T) {
+	req, err := http.NewRequest("GET", "", nil)
+	if err != nil {
+		t.Fatalf("error creating request: %v", err)
+	}
+	h := &serverHandler{}
+	rw := httptest.NewRecorder()
+	h.serveVersion(rw, req)
+	if rw.Code != http.StatusOK {
+		t.Errorf("code=%d, want %d", rw.Code, http.StatusOK)
+	}
+	w := fmt.Sprintf("etcd %s", version.Version)
+	if g := rw.Body.String(); g != w {
+		t.Fatalf("body = %q, want %q", g, w)
+	}
+}
+
+func TestServeVersionFails(t *testing.T) {
+	for _, m := range []string{
+		"CONNECT", "TRACE", "PUT", "POST", "HEAD",
+	} {
+		req, err := http.NewRequest(m, "", nil)
+		if err != nil {
+			t.Fatalf("error creating request: %v", err)
+		}
+		h := &serverHandler{}
+		rw := httptest.NewRecorder()
+		h.serveVersion(rw, req)
+		if rw.Code != http.StatusMethodNotAllowed {
+			t.Errorf("method %s: code=%d, want %d", m, rw.Code, http.StatusMethodNotAllowed)
+		}
+	}
+}
+
 func TestAllowMethod(t *testing.T) {
 	tests := []struct {
 		m  string