gitaly/server: Allow injecting custom interceptors

We're about to add some testserver-specific interceptors. Add the
infrastructure to add interceptors via options.

3 files changed, 40 insertions, 8 deletions

diff --git a/internal/gitaly/server/server.go b/internal/gitaly/server/server.go
index bb35a4cae..94f11279b 100644
--- a/internal/gitaly/server/server.go
+++ b/internal/gitaly/server/server.go
@@ -49,8 +49,35 @@ func init() {
 	grpcmwlogrus.ReplaceGrpcLogger(gitalylog.GrpcGo())
 }
 
+type serverConfig struct {
+	unaryInterceptors  []grpc.UnaryServerInterceptor
+	streamInterceptors []grpc.StreamServerInterceptor
+}
+
+// Option is an option that can be passed to `New()`.
+type Option func(*serverConfig)
+
+// WithUnaryInterceptor adds another interceptor that shall be executed for unary RPC calls.
+func WithUnaryInterceptor(interceptor grpc.UnaryServerInterceptor) Option {
+	return func(cfg *serverConfig) {
+		cfg.unaryInterceptors = append(cfg.unaryInterceptors, interceptor)
+	}
+}
+
+// WithStreamInterceptor adds another interceptor that shall be executed for streaming RPC calls.
+func WithStreamInterceptor(interceptor grpc.StreamServerInterceptor) Option {
+	return func(cfg *serverConfig) {
+		cfg.streamInterceptors = append(cfg.streamInterceptors, interceptor)
+	}
+}
+
 // New returns a GRPC server instance with a set of interceptors configured.
-func (s *GitalyServerFactory) New(secure bool) (*grpc.Server, error) {
+func (s *GitalyServerFactory) New(secure bool, opts ...Option) (*grpc.Server, error) {
+	var cfg serverConfig
+	for _, opt := range opts {
+		opt(&cfg)
+	}
+
 	ctxTagOpts := []grpcmwtags.Option{
 		grpcmwtags.WithFieldExtractorForInitialReq(fieldextractors.FieldExtractor),
 	}
@@ -140,7 +167,10 @@ func (s *GitalyServerFactory) New(secure bool) (*grpc.Server, error) {
 		panichandler.UnaryPanicHandler,
 	)
 
-	opts := []grpc.ServerOption{
+	streamServerInterceptors = append(streamServerInterceptors, cfg.streamInterceptors...)
+	unaryServerInterceptors = append(unaryServerInterceptors, cfg.unaryInterceptors...)
+
+	serverOptions := []grpc.ServerOption{
 		grpc.StatsHandler(gitalylog.PerRPCLogHandler{
 			Underlying:     &grpcstats.PayloadBytes{},
 			FieldProducers: []gitalylog.FieldsProducer{grpcstats.FieldsProducer},
@@ -161,5 +191,5 @@ func (s *GitalyServerFactory) New(secure bool) (*grpc.Server, error) {
 		}),
 	}
 
-	return grpc.NewServer(opts...), nil
+	return grpc.NewServer(serverOptions...), nil
 }
diff --git a/internal/gitaly/server/server_factory.go b/internal/gitaly/server/server_factory.go
index 00e2b615d..f9de03235 100644
--- a/internal/gitaly/server/server_factory.go
+++ b/internal/gitaly/server/server_factory.go
@@ -77,8 +77,8 @@ func (s *GitalyServerFactory) GracefulStop() {
 
 // CreateExternal creates a new external gRPC server. The external servers are closed
 // before the internal servers when gracefully shutting down.
-func (s *GitalyServerFactory) CreateExternal(secure bool) (*grpc.Server, error) {
-	server, err := s.New(secure)
+func (s *GitalyServerFactory) CreateExternal(secure bool, opts ...Option) (*grpc.Server, error) {
+	server, err := s.New(secure, opts...)
 	if err != nil {
 		return nil, err
 	}
@@ -89,8 +89,8 @@ func (s *GitalyServerFactory) CreateExternal(secure bool) (*grpc.Server, error)
 
 // CreateInternal creates a new internal gRPC server. Internal servers are closed
 // after the external ones when gracefully shutting down.
-func (s *GitalyServerFactory) CreateInternal() (*grpc.Server, error) {
-	server, err := s.New(false)
+func (s *GitalyServerFactory) CreateInternal(opts ...Option) (*grpc.Server, error) {
+	server, err := s.New(false, opts...)
 	if err != nil {
 		return nil, err
 	}
diff --git a/internal/testhelper/testserver/gitaly.go b/internal/testhelper/testserver/gitaly.go
index 6401cd25b..9ec09d357 100644
--- a/internal/testhelper/testserver/gitaly.go
+++ b/internal/testhelper/testserver/gitaly.go
@@ -185,7 +185,9 @@ func runGitaly(tb testing.TB, cfg config.Cfg, rubyServer *rubyserver.Server, reg
 		waitHealthy(tb, ctx, "unix://"+internalListener.Addr().String(), cfg.Auth.Token)
 	}
 
-	externalServer, err := serverFactory.CreateExternal(cfg.TLS.CertPath != "" && cfg.TLS.KeyPath != "")
+	secure := cfg.TLS.CertPath != "" && cfg.TLS.KeyPath != ""
+
+	externalServer, err := serverFactory.CreateExternal(secure)
 	require.NoError(tb, err)
 	tb.Cleanup(externalServer.Stop)