fix(gateway): switch to separate Listen/Serve

api/gateway/server.go

@@ -15,11 +15,12 @@ type Server struct {
  srv *http.Server
  srvMux *mux.Router // http request multiplexer
  listener net.Listener
- started atomic.Bool
+
+ started atomic.Bool
 }
 
 // NewServer returns a new gateway Server.
-func NewServer(address string, port string) *Server {
+func NewServer(address, port string) *Server {
  srvMux := mux.NewRouter()
  srvMux.Use(setContentType)
 
@@ -42,13 +43,12 @@ func (s *Server) Start(context.Context) error {
  log.Warn("cannot start server: already started")
  return nil
  }
-
  listener, err := net.Listen("tcp", s.srv.Addr)
  if err != nil {
  return err
  }
  s.listener = listener
- log.Infow("server started", "listening on", listener.Addr().String())
+ log.Infow("server started", "listening on", s.srv.Addr)
  //nolint:errcheck
  go s.srv.Serve(listener)
  return nil
@@ -65,6 +65,7 @@ func (s *Server) Stop(ctx context.Context) error {
  if err != nil {
  return err
  }
+ s.listener = nil
  log.Info("server stopped")
  return nil
 }
@@ -88,5 +89,8 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 // ListenAddr returns the listen address of the server.
 func (s *Server) ListenAddr() string {
+ if s.listener == nil {
+ return ""
+ }
  return s.listener.Addr().String()
 }

api/rpc/server.go

@@ -2,6 +2,7 @@ package rpc
 
 import (
  "context"
+ "net"
  "net/http"
  "sync/atomic"
  "time"
@@ -13,16 +14,18 @@ import (
 var log = logging.Logger("rpc")
 
 type Server struct {
- http *http.Server
- rpc *jsonrpc.RPCServer
+ srv *http.Server
+ rpc *jsonrpc.RPCServer
+ listener net.Listener
+
  started atomic.Bool
 }
 
-func NewServer(address string, port string) *Server {
+func NewServer(address, port string) *Server {
  rpc := jsonrpc.NewServer()
  return &Server{
  rpc: rpc,
- http: &http.Server{
+ srv: &http.Server{
  Addr: address + ":" + port,
  Handler: rpc,
  // the amount of time allowed to read request headers. set to the default 2 seconds
@@ -44,9 +47,14 @@ func (s *Server) Start(context.Context) error {
  log.Warn("cannot start server: already started")
  return nil
  }
+ listener, err := net.Listen("tcp", s.srv.Addr)
+ if err != nil {
+ return err
+ }
+ s.listener = listener
+ log.Infow("server started", "listening on", s.srv.Addr)
  //nolint:errcheck
- go s.http.ListenAndServe()
- log.Infow("server started", "listening on", s.http.Addr)
+ go s.srv.Serve(listener)
  return nil
 }
 
@@ -57,15 +65,19 @@ func (s *Server) Stop(ctx context.Context) error {
  log.Warn("cannot stop server: already stopped")
  return nil
  }
- err := s.http.Shutdown(ctx)
+ err := s.srv.Shutdown(ctx)
  if err != nil {
  return err
  }
+ s.listener = nil
  log.Info("server stopped")
  return nil
 }
 
 // ListenAddr returns the listen address of the server.
 func (s *Server) ListenAddr() string {
- return s.http.Addr
+ if s.listener == nil {
+ return ""
+ }
+ return s.listener.Addr().String()
 }

api/rpc_test.go

@@ -5,6 +5,7 @@ import (
  "encoding/json"
  "reflect"
  "testing"
+ "time"
 
  sdk "github.com/cosmos/cosmos-sdk/types"
  "github.com/golang/mock/gomock"
@@ -28,8 +29,20 @@ func TestRPCCallsUnderlyingNode(t *testing.T) {
  t.Cleanup(cancel)
  nd, server := setupNodeWithModifiedRPC(t)
  url := nd.RPCServer.ListenAddr()
- client, err := client.NewClient(context.Background(), "http://"+url)
- t.Cleanup(client.Close)
+ // we need to run this a few times to prevent the race where the server is not yet started
+ var (
+ rpcClient *client.Client
+ err error
+ )
+ for i := 0; i < 3; i++ {
+ time.Sleep(time.Second * 1)
+ rpcClient, err = client.NewClient(ctx, "http://"+url)
+ if err == nil {
+ t.Cleanup(rpcClient.Close)
+ break
+ }
+ }
+ require.NotNil(t, rpcClient)
  require.NoError(t, err)
 
  expectedBalance := &state.Balance{
@@ -39,7 +52,7 @@ func TestRPCCallsUnderlyingNode(t *testing.T) {
 
  server.State.EXPECT().Balance(gomock.Any()).Return(expectedBalance, nil).Times(1)
 
- balance, err := client.State.Balance(ctx)
+ balance, err := rpcClient.State.Balance(ctx)
  require.NoError(t, err)
  require.Equal(t, expectedBalance, balance)
 }
@@ -118,14 +131,16 @@ func setupNodeWithModifiedRPC(t *testing.T) (*nodebuilder.Node, *mockAPI) {
  dasMock.NewMockModule(ctrl),
  }
 
- overrideRPCHandler := fx.Invoke(func(srv *rpc.Server) {
+ // given the behavior of fx.Invoke, this invoke will be called last as it is added at the root level module. For
+ // further information, check the documentation on fx.Invoke.
+ invokeRPC := fx.Invoke(func(srv *rpc.Server) {
  srv.RegisterService("state", mockAPI.State)
  srv.RegisterService("share", mockAPI.Share)
  srv.RegisterService("fraud", mockAPI.Fraud)
  srv.RegisterService("header", mockAPI.Header)
  srv.RegisterService("das", mockAPI.Das)
  })
- nd := nodebuilder.TestNode(t, node.Full, overrideRPCHandler)
+ nd := nodebuilder.TestNode(t, node.Full, invokeRPC)
  // start node
  err := nd.Start(ctx)
  require.NoError(t, err)

nodebuilder/testing.go

@@ -46,7 +46,7 @@ func TestNodeWithConfig(t *testing.T, tp node.Type, cfg *Config, opts ...fx.Opti
  require.NoError(t, err)
  cfg.Core.IP = ip
  cfg.Core.RPCPort = port
- cfg.RPC.Port = "26655"
+ cfg.RPC.Port = "0"
 
  opts = append(opts,
  state.WithKeyringSigner(TestKeyringSigner(t)),