api: Add C support (#549)

api/Dockerfile-c

@@ -0,0 +1,16 @@
+FROM alpine:latest
+
+ENV PROJECT_PATH=/chirpstack/api
+RUN apk add --no-cache make git bash protobuf protobuf-dev pkgconfig autoconf automake libtool gcc g++
+
+# Install protobuf implementation for C
+RUN git clone --depth=1 https://github.com/protobuf-c/protobuf-c.git /protobuf-c
+RUN cd /protobuf-c && ./autogen.sh && ./configure && make && make install
+
+
+# Proto dependencies stuff
+RUN git clone --depth=1 https://github.com/protocolbuffers/protobuf.git /protobuf
+RUN git clone --depth=1 https://github.com/googleapis/googleapis.git /googleapis
+
+RUN mkdir -p PROJECT_PATH
+WORKDIR $PROJECT_PATH

api/Makefile

@@ -1,6 +1,6 @@
-.PHONY: rust grpc-web go js python md java kotlin csharp php
+.PHONY: rust grpc-web go js python md java kotlin csharp php c
 
-all: rust grpc-web go js python md java kotlin csharp php
+all: rust grpc-web go js python md java kotlin csharp php c
 
 rust:
 	cd rust && make
@@ -31,3 +31,6 @@ csharp:
 
 php:
 	docker compose run --rm chirpstack-api-php
+
+c:
+	docker compose run --rm chirpstack-api-c

api/c/.gitignore

@@ -0,0 +1,2 @@
+/src/
+/proto/

api/c/Makefile

@@ -0,0 +1,34 @@
+.PHONY: all pre-build
+
+PROTOC := protoc-c
+PROTOC_ARGS := -I=proto -I=proto/chirpstack-api --c_out=./src
+
+GOOGLE_PROTOBUF_REQUIREMENTS =
+GOOGLE_PROTOBUF_REQUIREMENTS += timestamp.proto
+GOOGLE_PROTOBUF_REQUIREMENTS += duration.proto
+GOOGLE_PROTOBUF_REQUIREMENTS += struct.proto
+GOOGLE_PROTOBUF_REQUIREMENTS += empty.proto
+GOOGLE_PROTOBUF_REQUIREMENTS += descriptor.proto
+GOOGLE_PROTOBUF_OUTPUT = $(patsubst %.proto, src/google/protobuf/%.pb-c.h, $(GOOGLE_PROTOBUF_REQUIREMENTS))
+
+all: pre-build $(GOOGLE_PROTOBUF_OUTPUT) build
+
+pre-build:
+	rm -rf proto src
+	mkdir -p proto/chirpstack-api
+	mkdir -p proto/google/protobuf
+	cp -r ../proto/* proto/chirpstack-api/
+	mv proto/chirpstack-api/google/api proto/google/api
+	mkdir -p src
+	sed -i \
+		-r 's/(\s+bytes std)(in|out|err)(\s+=.*)/\1_\2\3/' \
+		proto/chirpstack-api/gw/gw.proto
+
+src/google/protobuf/%.pb-c.h: /protobuf/src/google/protobuf/%.proto
+	cp $< proto/google/protobuf/
+
+build:
+	find proto \
+		-name '*.proto' \
+		-type f \
+		-exec $(PROTOC) $(PROTOC_ARGS) {} \;

api/docker-compose.yml

@@ -49,3 +49,10 @@ services:
     command: bash -c "cd php && make all"
     volumes:
       - ./:/chirpstack/api
+  chirpstack-api-c:
+    build:
+      context: .
+      dockerfile: Dockerfile-c
+    command: bash -c "cd c && make all"
+    volumes:
+      - ./:/chirpstack/api