grpc-gateway_out Cannot set flag

[artificial-james]

🐛 Bug Report

This morning (after the v2 release), when I attempt to generate the grpc-gateway, I get the following error:

goroutine 1 [running]:
github.com/golang/glog.stacks(0xc000157a00, 0xc000268240, 0x3c, 0x40)
	/go/src/github.com/golang/glog/glog.go:769 +0xb9
github.com/golang/glog.(*loggingT).output(0xb0bdc0, 0xc000000003, 0xc0000c7d50, 0xadb797, 0x7, 0x72, 0x0)
	/go/src/github.com/golang/glog/glog.go:720 +0x39a
github.com/golang/glog.(*loggingT).printf(0xb0bdc0, 0x3, 0x85b045, 0x12, 0xc000325be8, 0x1, 0x1)
	/go/src/github.com/golang/glog/glog.go:655 +0x153
github.com/golang/glog.Fatalf(...)
	/go/src/github.com/golang/glog/glog.go:1148
main.parseFlags(0xc0002209c0, 0x0, 0x0)
	/go/src/github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/main.go:114 +0x3b1
main.main.func1(0xc0003b7540, 0x0, 0xc000272000)
	/go/src/github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/main.go:68 +0x79
google.golang.org/protobuf/compiler/protogen.run(0xc000210ef0, 0x0, 0xc000325f30, 0xb0c720, 0x7f9b70382560)
	/go/src/google.golang.org/protobuf/compiler/protogen/protogen.go:75 +0x1e2
google.golang.org/protobuf/compiler/protogen.Options.Run(0xc000210ef0, 0x0, 0xc0001d3f30)
	/go/src/google.golang.org/protobuf/compiler/protogen/protogen.go:53 +0x5a
main.main()
	/go/src/github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/main.go:66 +0x2dd
--grpc-gateway_out: protoc-gen-grpc-gateway: Plugin failed with status code 255.

To Reproduce

Here is my protoc step:

protoc $(INC_PARAMS) \
		--go_out=plugins=grpc:$(OUT_DIR)/example \
		--grpc-gateway_out=$(OUT_DIR) \
		--openapiv2_out=logtostderr=true:$(OUT_DIR) \
		example/echo_service.proto

I found that I can get this to work with if I add an additional param to the grpc-gateway_out plugin, example:

protoc $(INC_PARAMS) \
		--go_out=plugins=grpc:$(OUT_DIR)/example \
		--grpc-gateway_out=version=true:$(OUT_DIR) \
		--openapiv2_out=logtostderr=true:$(OUT_DIR) \
		example/echo_service.proto

Expected behavior

No errors when generating grpc-gateway.

Actual Behavior

See above.

Your Environment

Docker (golang:1.15), protoc v3.13.0.

[johanbrandhorst]

Can you try --grpc-gateway_out $(OUT_DIR)? Our documentation recommends doing this in separate parameters like this.

[johanbrandhorst]

CC @adambabik