protoc-fetcher
Rust library for fetching official Protocol Buffer compiler (protoc
) releases, pegged to a specific version.
protoc-fetcher
downloads an official release of the protobuf compiler (protoc) and returns the path to it.
use std::env;
use std::path::Path;
// From within build.rs...
let protoc_version = "21.5";
let out_dir = env::var("OUT_DIR").unwrap();
let protoc_path = protoc_fetcher::protoc(protoc_version, Path::new(&out_dir));
The release archive matching the given version
will be downloaded, and the protoc binary will be extracted into a subdirectory of out_dir
. You can choose a version
from the release page, for example "21.5". Don't prefix it with a "v".
out_dir
can be anywhere you want, but if calling this function from a build script, you should probably use the OUT_DIR
env var (which is set by Cargo automatically for build scripts).
A previously downloaded protoc binary of the correct version will be reused if already present in out_dir
.
Usage with Tonic or Prost
If you are using tonic-build (or prost-build), you can instruct it to use the fetched protoc
binary by setting the PROTOC
env var.
use std::env;
use std::path::Path;
let out_dir = env::var("OUT_DIR").unwrap();
let path_to_my_protos = Path::new("a/b/c");
let protoc_path = protoc_fetcher::protoc("21.2", Path::new(&out_dir)).unwrap();
env::set_var("PROTOC", &protoc_path);
tonic_build::compile_protos(path_to_my_protos);