feat: add logging support to generated clients

Author: codyoss

internal/gengapic/client_init_test.go

@@ -414,6 +414,7 @@ func TestClientInit(t *testing.T) {
 				{Name: "iampb", Path: "cloud.google.com/go/iam/apiv1/iampb"}:                       true,
 				{Name: "locationpb", Path: "google.golang.org/genproto/googleapis/cloud/location"}: true,
 				{Name: "mypackagepb", Path: "github.com/googleapis/mypackage"}:                     true,
+				{Path: "log/slog"}: true,
 			},
 			wantNumSnps: 6,
 		},
@@ -436,6 +437,7 @@ func TestClientInit(t *testing.T) {
 				{Name: "iampb", Path: "cloud.google.com/go/iam/apiv1/iampb"}:                       true,
 				{Name: "locationpb", Path: "google.golang.org/genproto/googleapis/cloud/location"}: true,
 				{Name: "mypackagepb", Path: "github.com/googleapis/mypackage"}:                     true,
+				{Path: "log/slog"}:                                                                 true,
 			},
 			wantNumSnps: 6,
 		},
@@ -453,6 +455,7 @@ func TestClientInit(t *testing.T) {
 				{Name: "gtransport", Path: "google.golang.org/api/transport/grpc"}:    true,
 				{Name: "mypackagepb", Path: "github.com/googleapis/mypackage"}:        true,
 				{Name: "httptransport", Path: "google.golang.org/api/transport/http"}: true,
+				{Path: "log/slog"}:                                                    true,
 			},
 			wantNumSnps: 1,
 		},
@@ -472,6 +475,7 @@ func TestClientInit(t *testing.T) {
 				{Path: "context"}:                      true,
 				{Path: "google.golang.org/api/option"}: true,
 				{Path: "google.golang.org/grpc"}:       true,
+				{Path: "log/slog"}:                     true,
 			},
 			wantNumSnps: 6,
 		},
@@ -489,6 +493,7 @@ func TestClientInit(t *testing.T) {
 				{Path: "google.golang.org/api/option/internaloption"}: true,
 				{Path: "google.golang.org/grpc"}:                      true,
 				{Path: "net/http"}:                                    true,
+				{Path: "log/slog"}:                                    true,
 			},
 			wantNumSnps: 1,
 		},
@@ -506,6 +511,7 @@ func TestClientInit(t *testing.T) {
 				{Path: "net/http"}:                                                    true,
 				{Name: "httptransport", Path: "google.golang.org/api/transport/http"}: true,
 				{Name: "mypackagepb", Path: "github.com/googleapis/mypackage"}:        true,
+				{Path: "log/slog"}:                                                    true,
 			},
 			wantNumSnps: 1,
 			setExt: func() (protoreflect.ExtensionType, interface{}) {

internal/gengapic/gengapic.go

@@ -231,7 +231,18 @@ func (g *generator) genAndCommitHelpers(scopes []string) error {
 	p := g.printf
 	g.reset()
 	g.imports[pbinfo.ImportSpec{Path: "context"}] = true
+	g.imports[pbinfo.ImportSpec{Path: "io"}] = true
+	g.imports[pbinfo.ImportSpec{Path: "log/slog"}] = true
+	g.imports[pbinfo.ImportSpec{Path: "net/http"}] = true
 	g.imports[pbinfo.ImportSpec{Path: "google.golang.org/api/option"}] = true
+	g.imports[pbinfo.ImportSpec{Path: "github.com/googleapis/gax-go/v2/internallog"}] = true
+	g.imports[pbinfo.ImportSpec{Path: "github.com/googleapis/gax-go/v2/internallog/grpclog"}] = true
+	g.imports[pbinfo.ImportSpec{Path: "google.golang.org/api/googleapi"}] = true
+	g.imports[pbinfo.ImportSpec{Path: "google.golang.org/grpc"}] = true
+	g.imports[pbinfo.ImportSpec{Path: "google.golang.org/protobuf/proto"}] = true
+
+	p("const serviceName = %q", g.serviceConfig.GetName())
+	p("")
 
 	p("// For more information on implementing a client constructor hook, see")
 	p("// https://github.com/googleapis/google-cloud-go/wiki/Customizing-constructors.")
@@ -257,6 +268,52 @@ func (g *generator) genAndCommitHelpers(scopes []string) error {
 	}
 	p("  }")
 	p("}")
+	p("")
+
+	p("func executeHTTPRequest(ctx context.Context, client *http.Client, req *http.Request, logger *slog.Logger,	body []byte, rpc string) ([]byte, error) {")
+	p(`  logger.DebugContext(ctx, "api request", "serviceName", serviceName, "rpcName", rpc, "request", internallog.HTTPRequest(req, body))`)
+	p("  resp, err := client.Do(req)")
+	p("  if err != nil{")
+	p("    return nil, err")
+	p("  }")
+	p("  defer resp.Body.Close()")
+	p("  buf, err := io.ReadAll(resp.Body)")
+	p("  if err != nil {")
+	p("    return nil, err")
+	p("  }")
+	p(`  logger.DebugContext(ctx, "api response", "serviceName", serviceName, "rpcName", rpc, "response", internallog.HTTPResponse(resp, buf))`)
+	p("  if err = googleapi.CheckResponse(resp); err != nil {")
+	p("    return nil, err")
+	p("  }")
+	p("  return buf, nil")
+	p("}")
+	p("")
+
+	p("func executeStreamingHTTPRequest(ctx context.Context, client *http.Client, req *http.Request, logger *slog.Logger, body []byte, rpc string) (*http.Response, error) {")
+	p(`  logger.DebugContext(ctx, "api request", "serviceName", serviceName, "rpcName", rpc, "request", internallog.HTTPRequest(req, body))`)
+	p("  resp, err := client.Do(req)")
+	p("  if err != nil{")
+	p("    return nil, err")
+	p("  }")
+	p(`  logger.DebugContext(ctx, "api response", "serviceName", serviceName, "rpcName", rpc, "response", internallog.HTTPResponse(resp, nil))`)
+	p("  if err = googleapi.CheckResponse(resp); err != nil {")
+	p("    return nil, err")
+	p("  }")
+	p("  return resp, nil")
+	p("}")
+	p("")
+
+	p("func executeRPC[I proto.Message, O proto.Message](ctx context.Context, fn func(context.Context, I, ...grpc.CallOption) (O, error), req I, opts []grpc.CallOption, logger *slog.Logger, rpc string) (O, error) {")
+	p("  var zero O")
+	p(`  logger.DebugContext(ctx, "api request", "serviceName", serviceName, "rpcName", rpc, "request", grpclog.ProtoMessageRequest(ctx, req))`)
+	p("  resp, err := fn(ctx, req, opts...)")
+	p("  if err != nil {")
+	p("    return zero, err")
+	p("  }")
+	p(`  logger.DebugContext(ctx, "api response", "serviceName", serviceName, "rpcName", rpc, "response", grpclog.ProtoMessageResponse(resp))`)
+	p("  return resp, err")
+	p("}")
+	p("")
 
 	outFile := filepath.Join(g.opts.outDir, "helpers.go")
 	g.commit(outFile, g.opts.pkgName)

internal/gengapic/gengapic_test.go

@@ -1128,12 +1128,12 @@ func TestGRPCStubCall(t *testing.T) {
 	}{
 		{
 			name: "foo.FooService.GetFoo",
-			want: "c.client.GetFoo(ctx, req, settings.GRPC...)",
+			want: `executeRPC(ctx, c.client.GetFoo, req, settings.GRPC, c.logger, "GetFoo")`,
 			in:   getFoo,
 		},
 		{
 			name: "foo.BarService.GetBar",
-			want: "c.barClient.GetBar(ctx, req, settings.GRPC...)",
+			want: `executeRPC(ctx, c.barClient.GetBar, req, settings.GRPC, c.logger, "GetBar")`,
 			in:   getBar,
 		},
 	} {

internal/gengapic/gengrpc.go

@@ -162,7 +162,7 @@ func (g *generator) emptyUnaryGRPCCall(servName string, m *descriptorpb.MethodDe
 func (g *generator) grpcStubCall(method *descriptorpb.MethodDescriptorProto) string {
 	service := g.descInfo.ParentElement[method]
 	stub := pbinfo.ReduceServName(service.GetName(), g.opts.pkgName)
-	return fmt.Sprintf("c.%s.%s(ctx, req, settings.GRPC...)", grpcClientField(stub), method.GetName())
+	return fmt.Sprintf("executeRPC(ctx, c.%s.%s, req, settings.GRPC, c.logger, %q)", grpcClientField(stub), method.GetName(), method.GetName())
 }
 
 func (g *generator) grpcClientOptions(serv *descriptorpb.ServiceDescriptorProto, servName string) error {
@@ -295,6 +295,8 @@ func (g *generator) grpcClientInit(serv *descriptorpb.ServiceDescriptorProto, se
 
 	p("// The x-goog-* metadata to be sent with each request.")
 	p("xGoogHeaders []string")
+	p("")
+	p("logger *slog.Logger")
 
 	p("}")
 	p("")
@@ -303,6 +305,7 @@ func (g *generator) grpcClientInit(serv *descriptorpb.ServiceDescriptorProto, se
 	g.imports[imp] = true
 
 	g.grpcClientUtilities(serv, servName, imp, hasRPCForLRO)
+	g.imports[pbinfo.ImportSpec{Path: "log/slog"}] = true
 }
 
 func (g *generator) grpcClientUtilities(serv *descriptorpb.ServiceDescriptorProto, servName string, imp pbinfo.ImportSpec, hasRPCForLRO bool) {
@@ -337,6 +340,7 @@ func (g *generator) grpcClientUtilities(serv *descriptorpb.ServiceDescriptorProt
 	p("    connPool:    connPool,")
 	p("    %s: %s.New%sClient(connPool),", grpcClientField(servName), imp.Name, serv.GetName())
 	p("    CallOptions: &client.CallOptions,")
+	p("    logger: internaloption.GetLogger(opts),")
 	g.mixinStubsInit()
 	p("")
 	p("  }")