protoc in makefile to build protobuf

Question

I have installed a protocol buffer like the tutorial on https://github.com/google/protobuf/blob/master/src/README.md

after that I want to build protobuf and install go library with command as follows:

go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway
go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger
go get -u github.com/golang/protobuf/protoc-gen-go
make # generate app and protobuf

I have file Makefile on my root like this :

get:
    echo "Build Proto"
    protoc -I/usr/local/include -I. -I$GOPATH/src -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis proto/item.proto --go_out=plugins=grpc:.
    protoc -I/usr/local/include -I. -I$GOPATH/src -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis proto/item.proto --grpc-gateway_out=logtostderr=true:.
    protoc -I/usr/local/include -I. -I$GOPATH/src -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis proto/item.proto --swagger_out=logtostderr=true:.
    echo "Build APP"
    CGO_ENABLED=0 GOOS=linux go build -o ./server/storeitemservice ./server/cmd/server/main.go

but I want to generate app and protobuf in my root of application with the command make to build my app and the result like this:

echo "Build Proto"
Build Proto
protoc -I/usr/local/include -I. -IOPATH/src -IOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis proto/item.proto --go_out=plugins=grpc:.
OPATH/src: warning: directory does not exist.
OPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis: warning: directory does not exist.
google/api/annotations.proto: File not found.
proto/item.proto: Import "google/api/annotations.proto" was not found or had errors.
Makefile:2: recipe for target 'get' failed
make: *** [get] Error 1

after seeing the problem like this I check each of its directory, and it turns out there is all.

Answer 1

You'll need to wrap your $GOPATH like this

protoc -I/usr/local/include -I. -I$(GOPATH)/src \
       -I$(GOPATH)/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
       proto/item.proto --go_out=plugins=grpc:.

\\ added to make it easier to read here. The key is $(GOPATH) vs $GOPATH

Here is a demo:

get:
    echo $(GOPATH)
    echo $GOPATH

and the output

echo /Users/sberry/Development/golang
/Users/sberry/Development/golang
echo OPATH
OPATH

In an editor that knows Makefile syntax you can see the difference