pubsub: gRPC Dial Option is ignored if PUBSUB_EMULATOR_HOST is set

[toga4]

Client

PubSub

Environment

MacOS

Go Environment

$ go version
go version go1.22.2 darwin/arm64

$ go env
GO111MODULE=''
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/tomoki.t/Library/Caches/go-build'
GOENV='/Users/tomoki.t/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/tomoki.t/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/tomoki.t/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/opt/homebrew/Cellar/go/1.22.2/libexec'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/opt/homebrew/Cellar/go/1.22.2/libexec/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.22.2'
GCCGO='gccgo'
AR='ar'
CC='cc'
CXX='c++'
CGO_ENABLED='1'
GOMOD='/dev/null'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/d5/bmk880x11pz8xh80bh9djr3m0000gn/T/go-build1444610399=/tmp/go-build -gno-record-gcc-switches -fno-common'

Code

e.g.

func main() {
	os.Setenv("PUBSUB_EMULATOR_HOST", "localhost:8085")
	ctx := context.Background()

	client, err := pubsub.NewClient(
		ctx,
		"foo-project",
		option.WithGRPCDialOption(
			grpc.WithChainUnaryInterceptor(func(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
				fmt.Println("grpc.WithChainUnaryInterceptor")
				return invoker(ctx, method, req, reply, cc, opts...)
			}),
		),
	)
	if err != nil {
		panic(err)
	}
	defer client.Close()

	topic := client.Topic("foo-topic")
	result := topic.Publish(ctx, &pubsub.Message{
		Data: []byte("Hello, World!"),
	})

	if _, err := result.Get(ctx); err != nil {
		panic(err)
	}
}

Expected behavior

Expected to see output from the grpc.WithChainUnaryInterceptor indicating that the interceptor is being called.

Actual behavior

No output from the interceptor is observed, suggesting it's not being called.

Additional context

When PUBSUB_EMULATOR_HOST is set, a gRPC connection is generated using only grpc.WithInsecure, which results in all gRPC DialOptions being ignored.

google-cloud-go/pubsub/pubsub.go

Lines 142 to 151 in 4d85153

	var o []option.ClientOption
	// Environment variables for gcloud emulator:
	// https://cloud.google.com/sdk/gcloud/reference/beta/emulators/pubsub/
	if addr := os.Getenv("PUBSUB_EMULATOR_HOST"); addr != "" {
	conn, err := grpc.Dial(addr, grpc.WithInsecure())
	if err != nil {
	return nil, fmt.Errorf("grpc.Dial: %w", err)
	}
	o = []option.ClientOption{option.WithGRPCConn(conn)}
	o = append(o, option.WithTelemetryDisabled())

[hongalex]

Thank for you the PR and your patience while I get this merged in. Will try to get this merged in this week.