Tag Archives: protobuf

Protobuf: safer usage for buf

A drop-in replacement for buf issued by Ozon. Repository: https://github.com/easyp-tech/server Presentation (for subscribers only, unfortunately): https://conf.ontico.ru/online/hl2023/details/5206585

Protobuf: add header parameters

They finally added it to the grpc-gateway: https://github.com/grpc-ecosystem/grpc-gateway/pull/3010/files#diff-c255ac405628aada46c25a2c9765605e9f823bc523d3739fd3fa71d4bcbf5c99. So, to use it you can just update to the version 2.14.0 or above — https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v2.14.0, and add something like this to your protofile:

        option (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_operation) = {
            summary: "Create a new foo.";
            parameters: {
                headers: {
                    name: "My-Custom-Header";
                    description: "Some custom header description";
                    required: true;
                };
            };
        };

option (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_operation) = {

summary: "Create a new foo.";

parameters: {

headers: {

name: "My-Custom-Header";

description: "Some custom header description";

required: true;

};

Golang. Adding a json body to POST request in protofile

It could be a bit tricky, and I failed to find a good example for it.

Useful links for proto generator development

https://rotemtam.com/2021/03/22/creating-a-protoc-plugin-to-gen-go-code/ https://medium.com/@tim.r.coulson/writing-a-protoc-plugin-with-google-golang-org-protobuf-cd5aa75f5777 https://github.com/nametake/protoc-gen-gohttp https://github.com/drekle/protoc-gen-goexample/blob/c60883c9711f3cfbd5191fd697651dbd067e6fdd/main.go#L135 https://github.com/grpc-ecosystem/grpc-gateway/blob/24434e22fb9734f1a62c81c4ea246125d7844645/examples/internal/proto/examplepb/echo_service_grpc.pb.go https://pkg.go.dev/google.golang.org/protobuf/compiler/protogen#Options.Run https://github.com/lyft/protoc-gen-star https://go.dev/blog/protobuf-apiv2 https://docs.buf.build/build/usage/#configuration https://github.com/grpc-ecosystem/grpc-gateway https://github.com/googleapis/googleapis/tree/master/google/api https://github.com/bufbuild/buf https://stackoverflow.com/questions/36540427/cannot-find-package-google-protobuf https://pkg.go.dev/google.golang.org/protobuf https://developers.google.com/protocol-buffers/docs/reference/go-generated#package https://stackoverflow.com/questions/61666805/correct-format-of-protoc-go-package https://grpc.io/docs/languages/go/quickstart/ https://github.com/protocolbuffers/protobuf/tree/master/src/google/protobuf https://github.com/gogo/protobuf/blob/b03c65ea87cdc3521ede29f62fe3ce239267c1bc/protobuf/google/protobuf/descriptor.proto

Nullable fields in json generated from protobuf file

Native support With grpc v2 for go, protofile’s optional option is supported, so you don’t need to import proto extensions anymore and use things like google.protobuf.StringValue. my.proto

message FeeView {
    optional string name = 1 [json_name = "name"];
}

message FeeView {

optional string name = 1 [json_name = "name"];

}

go mapper

var name *string
if fee.Name != nil {
	name = &fee.Name
}

fee := &desc.FeeView{
	Name: name,
}

var name *string

if fee.Name != nil {

name = &fee.Name

}

fee := &desc.FeeView{

Name: name,

}

Legacy way with extensions Null for nil value my.proto

import "google/protobuf/wrappers.proto";

message FeeView {
    google.protobuf.StringValue name = 1 [json_name = "name"];
}

import "google/protobuf/wrappers.proto";

message FeeView {

google.protobuf.StringValue name = 1 [json_name = "name"];

}

go mapper

import "github.com/gogo/protobuf/types"

var name *types.StringValue
if fee.Name != nil {
	name = &types.StringValue{
		Value: *fee.Name,
	}
}

fee := &desc.FeeView{
	Name: name,
}

import "github.com/gogo/protobuf/types"

var name *types.StringValue

if fee.Name != nil {

name = &types.StringValue{

Value: *fee.Name,

}

fee := &desc.FeeView{

Name: name,

}

Which will lead to this json response

{"translation_key":"a fee","name":null,"value":5,"style":"body","text_color":"grey","tag":null}

1	{"translation_key":"a fee","name":null,"value":5,"style":"body","text_color":"grey","tag":null}

Omit a field …

Complete list of swagger options to protobuf file

Here is an example with many options that help generate proper swagger out of protofile. Original URL — https://raw.githubusercontent.com/grpc-ecosystem/grpc-gateway/master/examples/internal/proto/examplepb/a_bit_of_everything.proto.

Installing protobuf tools on MacOS

Installing protoc

brew install protobuf

1	brew install protobuf

Or follow different instructions. Installing grpc_cli Option 1. Easy way.

brew tap grpc/grpc
brew install --with-plugins grpc

1 2	brew tap grpc/grpc brew install --with-plugins grpc

It is described here — https://github.com/grpc/homebrew-grpc. Option 2. Hard way — using cmake and make. NOT RECOMMENDED.

brew install autoconf automake libtool shtool cmake

git clone -b $(curl -L https://grpc.io/release) https://github.com/grpc/grpc
cd grpc
git submodule update --init

mkdir -p cmake/build
cd cmake/build
cmake ../..
make

gRPC_INSTALL=ON make install
# and continue accordgin to https://github.com/grpc/grpc/blob/master/BUILDING.md

brew install autoconf automake libtool shtool cmake

git clone -b $(curl -L https://grpc.io/release) https://github.com/grpc/grpc

cd grpc

git submodule update --init

mkdir -p cmake/build

cd cmake/build

cmake ../..

make

gRPC_INSTALL=ON make install

# and continue accordgin to https://github.com/grpc/grpc/blob/master/BUILDING.md

Or follow these instructions