Remove dependency on github.com/grpc-ecosystem/grpc-gateway

[yurishkuro]

As far as I can tell, we are not using it today. The motivation for it was to have a canonical proto-based JSON API that would be used by the UI as well as a public API. But there are issues with proto-based JSON (e.g. IDs are represented in base64 instead of hex)
and updating the UI is a large task that we don't have the cycles for. I suggest we remove this dependency altogether until the time we actually need it.

$ grx grpc-gateway .
./idl/proto/api_v2/sampling.proto:34:// Enable registration with golang/protobuf for the grpc-gateway.
./idl/proto/api_v2/query.proto:37:// Enable registration with golang/protobuf for the grpc-gateway.
./idl/proto/api_v2/collector.proto:35:// Enable registration with golang/protobuf for the grpc-gateway.
./idl/proto/api_v2/model.proto:38:// Enable registration with golang/protobuf for the grpc-gateway.
./go.mod:35:	github.com/grpc-ecosystem/grpc-gateway v1.14.5
./Makefile:476:	# Generate gogo, gRPC-Gateway, swagger, go-validators, gRPC-storage-plugin output.
./Makefile:484:	# --grpc-gateway_out generates gRPC-Gateway output.
./Makefile:485:	# --swagger_out generates an OpenAPI 2.0 specification for our gRPC-Gateway endpoints.
./Makefile:506:		### grpc-gateway generates 'query.pb.gw.go' that does not respect (gogoproto.customname) = "TraceID"
./Makefile:507:		### --grpc-gateway_out=$(PROTO_GOGO_MAPPINGS):$(PWD)/proto-gen/ \
./proto-gen/api_v2/sampling.pb.go:14:	_ "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger/options"
./proto-gen/api_v2/query.pb.go:15:	_ "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger/options"
./proto-gen/api_v2/collector.pb.go:13:	_ "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger/options"
./plugin/storage/grpc/proto/storage.proto:34:// Enable registration with golang/protobuf for the grpc-gateway.
./tools.go:23:	_ "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger"
./go.sum:313:github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
./go.sum:314:github.com/grpc-ecosystem/grpc-gateway v1.9.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
./go.sum:315:github.com/grpc-ecosystem/grpc-gateway v1.14.5 h1:aiLxiiVzAXb7wb3lAmubA69IokWOoUNe+E7TdGKh8yw=
./go.sum:316:github.com/grpc-ecosystem/grpc-gateway v1.14.5/go.mod h1:UJ0EZAp832vCd54Wev9N1BMKEyvcZ5+IM0AwDrnlkEc=

[jeffy-mathew]

Hi, I would like to work on this issue

[yurishkuro]

@jeffy-mathew it's yours

[jeffy-mathew]

@yurishkuro I need some help in generating proto files, how to remove the dependency from generated proto files?

[yurishkuro]

oh, you may need to make a change to jaeger-idl repo and remove the respective annotations from these files:

./idl/proto/api_v2/sampling.proto
./idl/proto/api_v2/query.proto
./idl/proto/api_v2/collector.proto
./idl/proto/api_v2/model.proto

[jeffy-mathew]

about the changes in submodule jaeger-idl, do I need to raise a separate PR in that repo?

[yurishkuro]

Yes, a PR there and after it's merged update the submodule in this repo.