Fix errcheck in temporal/ (#3757)

Author: MichaelSnowden

temporal/fx.go

@@ -279,8 +279,8 @@ func (s ServerFx) Start() error {
 	return s.app.Start(context.Background())
 }
 
-func (s ServerFx) Stop() {
-	s.app.Stop(context.Background())
+func (s ServerFx) Stop() error {
+	return s.app.Stop(context.Background())
 }
 
 func StopService(logger log.Logger, app *fx.App, svcName primitives.ServiceName, stopChan chan struct{}) {
@@ -765,8 +765,7 @@ func ServerLifetimeHooks(
 				return svr.Start()
 			},
 			OnStop: func(ctx context.Context) error {
-				svr.Stop()
-				return nil
+				return svr.Stop()
 			},
 		},
 	)
@@ -880,8 +879,7 @@ var ServiceTracingModule = fx.Options(
 	fx.Provide(func(lc fx.Lifecycle, opts []otelsdktrace.TracerProviderOption) trace.TracerProvider {
 		tp := otelsdktrace.NewTracerProvider(opts...)
 		lc.Append(fx.Hook{OnStop: func(ctx context.Context) error {
-			tp.Shutdown(ctx)
-			return nil // do not pass this up to fx
+			return tp.Shutdown(ctx)
 		}})
 		return tp
 	}),

temporal/server.go

@@ -39,7 +39,7 @@ const (
 type (
 	Server interface {
 		Start() error
-		Stop()
+		Stop() error
 	}
 )
 

temporal/server_impl.go

@@ -30,6 +30,7 @@ import (
 	"sync"
 
 	"go.uber.org/fx"
+	"go.uber.org/multierr"
 
 	"go.temporal.io/server/common/cluster"
 	"go.temporal.io/server/common/config"
@@ -95,8 +96,10 @@ func (s *ServerImpl) Start() error {
 	s.logger.Info("Starting server for services", tag.Value(s.so.serviceNames))
 	s.logger.Debug(s.so.config.String())
 
+	ctx := context.TODO()
+
 	if err := initSystemNamespaces(
-		context.TODO(),
+		ctx,
 		&s.persistenceConfig,
 		s.clusterMetadata.CurrentClusterName,
 		s.so.persistenceServiceResolver,
@@ -107,30 +110,22 @@ func (s *ServerImpl) Start() error {
 		return fmt.Errorf("unable to initialize system namespace: %w", err)
 	}
 
-	var wg sync.WaitGroup
-	for _, svcMeta := range s.servicesMetadata {
-		wg.Add(1)
-		go func(svcMeta *ServicesMetadata) {
-			timeoutCtx, cancelFunc := context.WithTimeout(context.Background(), serviceStartTimeout)
-			defer cancelFunc()
-			svcMeta.App.Start(timeoutCtx)
-			wg.Done()
-		}(svcMeta)
+	if err := s.startServices(); err != nil {
+		return err
 	}
-	wg.Wait()
 
 	if s.so.blockingStart {
 		// If s.so.interruptCh is nil this will wait forever.
 		interruptSignal := <-s.so.interruptCh
 		s.logger.Info("Received interrupt signal, stopping the server.", tag.Value(interruptSignal))
-		s.Stop()
+		return s.Stop()
 	}
 
 	return nil
 }
 
 // Stop stops the server.
-func (s *ServerImpl) Stop() {
+func (s *ServerImpl) Stop() error {
 	var wg sync.WaitGroup
 	wg.Add(len(s.servicesMetadata))
 	close(s.stoppedCh)
@@ -147,6 +142,38 @@ func (s *ServerImpl) Stop() {
 	if s.so.metricHandler != nil {
 		s.so.metricHandler.Stop(s.logger)
 	}
+	return nil
+}
+
+func (s *ServerImpl) startServices() error {
+	ctx, cancel := context.WithTimeout(context.Background(), serviceStartTimeout)
+	defer cancel()
+	results := make(chan startServiceResult, len(s.servicesMetadata))
+	for _, svcMeta := range s.servicesMetadata {
+		go func(svcMeta *ServicesMetadata) {
+			err := svcMeta.App.Start(ctx)
+			results <- startServiceResult{
+				svc: svcMeta,
+				err: err,
+			}
+		}(svcMeta)
+	}
+	return s.readResults(results)
+}
+
+func (s *ServerImpl) readResults(results chan startServiceResult) (err error) {
+	for i := 0; i < len(s.servicesMetadata); i++ {
+		r := <-results
+		if r.err != nil {
+			err = multierr.Combine(err, fmt.Errorf("failed to start service %v: %w", r.svc.ServiceName, r.err))
+		}
+	}
+	return
+}
+
+type startServiceResult struct {
+	svc *ServicesMetadata
+	err error
 }
 
 func initSystemNamespaces(