cln

Generating Go gRPC Code

The Go gRPC bindings for Core Lightning (CLN) are generated from proto files that live in the lightning repository (cln-grpc) and in the hold plugin repository.

The generated Go files are written into the hub repository under lnclient/cln/clngrpc and lnclient/cln/clngrpc_hold.

Prerequisites

Make sure the following tools are installed:

# protoc (>= 3.20 recommended)
protoc --version

# Go plugins
go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

Ensure $GOPATH/bin is in your PATH:

export PATH="$PATH:$(go env GOPATH)/bin"

This guide assumes the following directory structure:

~/dev/
├── lightning/
│   └── cln-grpc/
│       └── proto/
│           ├── node.proto
│           ├── primitives.proto
│           └── ...
├── hub/
|   └── lnclient/
|       └── cln/
|           └── clngrpc/
|           └── clngrpc_hold/
└── hold/
    └── protos/
        └── hold.proto

Generating Go code

From the hub repository root, run:

protoc \
  --proto_path=../lightning/cln-grpc/proto \
  --go_out=./lnclient/cln/clngrpc \
  --go_opt=paths=source_relative \
  --go_opt=Mprimitives.proto=github.com/getAlby/hub/lnclient/cln/clngrpc \
  --go_opt=Mnode.proto=github.com/getAlby/hub/lnclient/cln/clngrpc \
  --go-grpc_out=./lnclient/cln/clngrpc \
  --go-grpc_opt=paths=source_relative \
  --go-grpc_opt=Mprimitives.proto=github.com/getAlby/hub/lnclient/cln/clngrpc \
  --go-grpc_opt=Mnode.proto=github.com/getAlby/hub/lnclient/cln/clngrpc \
  ../lightning/cln-grpc/proto/node.proto \
  ../lightning/cln-grpc/proto/primitives.proto

and if you have the hold plugin repo:

protoc \
  --proto_path=../hold/protos \
  --go_out=./lnclient/cln/clngrpc_hold \
  --go_opt=paths=source_relative \
  --go_opt=Mhold.proto=github.com/getAlby/hub/lnclient/cln/clngrpc_hold \
  --go-grpc_out=./lnclient/cln/clngrpc_hold \
  --go-grpc_opt=paths=source_relative \
  --go-grpc_opt=Mhold.proto=github.com/getAlby/hub/lnclient/cln/clngrpc_hold \
  ../hold/protos/hold.proto