move gRPC listener creation outside of grpcServer

For tests, we need to create the grpc listener with port 0 in order to
automatically assign a port. This PR moves the lister creation outside
of the grcpServer itself so that we can access that auto-created port.

cluster.go

@@ -71,6 +71,7 @@ const (
 type Node struct {
 	ID            string `json:"id"`
 	URI           URI    `json:"uri"`
+	GRPCURI       URI    `json:"grpc-uri"`
 	IsCoordinator bool   `json:"isCoordinator"`
 	State         string `json:"state"`
 }

server.go

@@ -70,6 +70,7 @@ type Server struct { // nolint: maligned
 
 	nodeID              string
 	uri                 URI
+	grpcURI             URI
 	antiEntropyInterval time.Duration
 	metricInterval      time.Duration
 	diagnosticInterval  time.Duration
@@ -236,6 +237,15 @@ func OptServerURI(uri *URI) ServerOption {
 	}
 }
 
+// OptServerGRPCURI is a functional option on Server
+// used to set the server gRPC URI.
+func OptServerGRPCURI(uri *URI) ServerOption {
+	return func(s *Server) error {
+		s.grpcURI = *uri
+		return nil
+	}
+}
+
 // OptServerClusterDisabled tells the server whether to use a static cluster with the
 // defined hosts. Mostly used for testing.
 func OptServerClusterDisabled(disabled bool, hosts []string) ServerOption {
@@ -370,6 +380,7 @@ func NewServer(opts ...ServerOption) (*Server, error) {
 	node := &Node{
 		ID:            s.nodeID,
 		URI:           s.uri,
+		GRPCURI:       s.grpcURI,
 		IsCoordinator: s.cluster.Coordinator == s.nodeID,
 		State:         nodeStateDown,
 	}

server/grpc.go

@@ -736,7 +736,7 @@ func (h grpcHandler) Inspect(req *pb.InspectRequest, stream pb.Pilosa_InspectSer
 type grpcServer struct {
 	api        *pilosa.API
 	grpcServer *grpc.Server
-	hostPort   string
+	ln         net.Listener
 
 	logger logger.Logger
 	stats  stats.StatsClient
@@ -751,10 +751,9 @@ func OptGRPCServerAPI(api *pilosa.API) grpcServerOption {
 	}
 }
 
-func OptGRPCServerURI(uri *pilosa.URI) grpcServerOption {
-	hostport := fmt.Sprintf("%s:%d", uri.Host, uri.Port)
+func OptGRPCServerListener(ln net.Listener) grpcServerOption {
 	return func(s *grpcServer) error {
-		s.hostPort = hostport
+		s.ln = ln
 		return nil
 	}
 }
@@ -774,12 +773,7 @@ func OptGRPCServerStats(stats stats.StatsClient) grpcServerOption {
 }
 
 func (s *grpcServer) Serve(tlsConfig *tls.Config) error {
-	// create listener
-	lis, err := net.Listen("tcp", s.hostPort)
-	if err != nil {
-		return errors.Wrap(err, "creating listener")
-	}
-	s.logger.Printf("enabled grpc listening on %s", lis.Addr())
+	s.logger.Printf("enabled grpc listening on %s", s.ln.Addr())
 
 	opts := make([]grpc.ServerOption, 0)
 	if tlsConfig != nil {
@@ -795,7 +789,7 @@ func (s *grpcServer) Serve(tlsConfig *tls.Config) error {
 	reflection.Register(s.grpcServer)
 
 	// and start...
-	if err := s.grpcServer.Serve(lis); err != nil {
+	if err := s.grpcServer.Serve(s.ln); err != nil {
 		return errors.Wrap(err, "starting grpc server")
 	}
 	return nil

server/server.go

@@ -82,6 +82,7 @@ type Command struct {
 
 	Handler      pilosa.Handler
 	grpcServer   *grpcServer
+	grpcLn       net.Listener
 	API          *pilosa.API
 	ln           net.Listener
 	listenURI    *pilosa.URI
@@ -270,6 +271,17 @@ func (m *Command) SetupServer() error {
 		return errors.Wrap(err, "processing bind grpc address")
 	}
 
+	// create gRPC listener
+	m.grpcLn, err = net.Listen("tcp", grpcURI.HostPort())
+	if err != nil {
+		return errors.Wrap(err, "creating grpc listener")
+	}
+
+	// If grpc port is 0, get auto-allocated port from listener
+	if grpcURI.Port == 0 {
+		grpcURI.SetPort(uint16(m.grpcLn.Addr().(*net.TCPAddr).Port))
+	}
+
 	// Setup TLS
 	if uri.Scheme == "https" {
 		m.tlsConfig, err = GetTLSConfig(&m.Config.TLS, m.logger.Logger())
@@ -340,6 +352,7 @@ func (m *Command) SetupServer() error {
 		pilosa.OptServerGCNotifier(gcnotify.NewActiveGCNotifier()),
 		pilosa.OptServerStatsClient(statsClient),
 		pilosa.OptServerURI(advertiseURI),
+		pilosa.OptServerGRPCURI(grpcURI),
 		pilosa.OptServerInternalClient(http.NewInternalClientFromURI(uri, c)),
 		pilosa.OptServerClusterDisabled(m.Config.Cluster.Disabled, m.Config.Cluster.Hosts),
 		pilosa.OptServerSerializer(proto.Serializer{}),
@@ -375,7 +388,7 @@ func (m *Command) SetupServer() error {
 
 	m.grpcServer, err = NewGRPCServer(
 		OptGRPCServerAPI(m.API),
-		OptGRPCServerURI(grpcURI),
+		OptGRPCServerListener(m.grpcLn),
 		OptGRPCServerLogger(m.logger),
 		OptGRPCServerStats(statsClient),
 	)