build.rs

// This build script is used to generate the rust source files that
// we need for XDS GRPC communication.
fn main() -> Result<(), anyhow::Error> {
    let proto_files = vec![
        "proto/xds.proto",
        "proto/workload.proto",
        "proto/citadel.proto",
    ]
    .iter()
    .map(|name| std::env::current_dir().unwrap().join(name))
    .collect::<Vec<_>>();
    let include_dirs = vec!["proto/"]
        .iter()
        .map(|i| std::env::current_dir().unwrap().join(i))
        .collect::<Vec<_>>();
    let config = {
        let mut c = prost_build::Config::new();
        c.disable_comments(Some("."));
        c.bytes(&[".istio.workload.Workload"]);
        c
    };
    tonic_build::configure()
        .build_server(true)
        .compile_with_config(
            config,
            &proto_files
                .iter()
                .map(|path| path.to_str().unwrap())
                .collect::<Vec<_>>(),
            &include_dirs
                .iter()
                .map(|p| p.to_str().unwrap())
                .collect::<Vec<_>>(),
        )?;

    // This tells cargo to re-run this build script only when the proto files
    // we're interested in change or the any of the proto directories were updated.
    for path in vec![proto_files, include_dirs].concat() {
        println!("cargo:rerun-if-changed={}", path.to_str().unwrap());
    }

    Ok(())
}