etcdhttp: add Peers.Endpoints

etcdserver/etcdhttp/http.go

@@ -85,6 +85,20 @@ func (ps Peers) IDs() []int64 {
 	return ids
 }
 
+// Endpoints returns a list of all peer addresses. Each address is
+// prefixed with "http://". The returned list is sorted (asc).
+func (ps Peers) Endpoints() []string {
+	endpoints := make([]string, 0)
+	for _, addrs := range ps {
+		for _, addr := range addrs {
+			endpoints = append(endpoints, addScheme(addr))
+		}
+	}
+	sort.Strings(endpoints)
+
+	return endpoints
+}
+
 var errClosed = errors.New("etcdhttp: client closed connection")
 
 const DefaultTimeout = 500 * time.Millisecond
@@ -209,14 +223,8 @@ func (h Handler) serveMachines(w http.ResponseWriter, r *http.Request) {
 		allow(w, "GET", "HEAD")
 		return
 	}
-	urls := make([]string, 0)
-	for _, addrs := range h.Peers {
-		for _, addr := range addrs {
-			urls = append(urls, addScheme(addr))
-		}
-	}
-	sort.Strings(urls)
-	w.Write([]byte(strings.Join(urls, ", ")))
+	endpoints := h.Peers.Endpoints()
+	w.Write([]byte(strings.Join(endpoints, ", ")))
 }
 
 func (h Handler) serveRaft(ctx context.Context, w http.ResponseWriter, r *http.Request) {

etcdserver/etcdhttp/http_test.go

@@ -397,3 +397,57 @@ func TestServeMachines(t *testing.T) {
 		t.Errorf("header = %d, want %d", writer.Code, http.StatusOK)
 	}
 }
+
+func TestPeersEndpoints(t *testing.T) {
+	tests := []struct {
+		peers     Peers
+		endpoints []string
+	}{
+		// single peer with a single address
+		{
+			peers: Peers(map[int64][]string{
+				1: []string{"192.0.2.1"},
+			}),
+			endpoints: []string{"http://192.0.2.1"},
+		},
+
+		// single peer with a single address with a port
+		{
+			peers: Peers(map[int64][]string{
+				1: []string{"192.0.2.1:8001"},
+			}),
+			endpoints: []string{"http://192.0.2.1:8001"},
+		},
+
+		// several peers explicitly unsorted
+		{
+			peers: Peers(map[int64][]string{
+				2: []string{"192.0.2.3", "192.0.2.4"},
+				3: []string{"192.0.2.5", "192.0.2.6"},
+				1: []string{"192.0.2.1", "192.0.2.2"},
+			}),
+			endpoints: []string{"http://192.0.2.1", "http://192.0.2.2", "http://192.0.2.3", "http://192.0.2.4", "http://192.0.2.5", "http://192.0.2.6"},
+		},
+
+		// no peers
+		{
+			peers:     Peers(map[int64][]string{}),
+			endpoints: []string{},
+		},
+
+		// peer with no endpoints
+		{
+			peers: Peers(map[int64][]string{
+				3: []string{},
+			}),
+			endpoints: []string{},
+		},
+	}
+
+	for i, tt := range tests {
+		endpoints := tt.peers.Endpoints()
+		if !reflect.DeepEqual(tt.endpoints, endpoints) {
+			t.Errorf("#%d: peers.Endpoints() incorrect: want=%#v got=%#v", i, tt.endpoints, endpoints)
+		}
+	}
+}