johnmq / heroku-buildpack-rust

A new, from-scratch buildpack for Rust applications on Heroku.

This is a replacement for Eric Fode's excellent heroku-buildpack-rust, but with support for recent Rust nightly builds and Cargo. The intention is that this will involve into a production-quality, supported buildpack as Rust and Cargo mature.

Tracking dependencies with Cargo

This is now the supported way of using this buildpack. For instructions and example code, see Deploying Rust applications to Heroku, with example code for Iron and heroku-rust-cargo-hello.

The older support for git submodule-based projects is deprecated, and will be phased out at some point.

Development notes

If you need to tweak this buildpack, the following information may help.

Testing with Vagrant

To test changes to the buildpack using the included Vagrantfile, run:

cp -a ../heroku-rust-cargo-hello . # Or whatever you want to test.
vagrant up
vagrant ssh
cd /vagrant
mkdir cache
bin/compile `pwd`/heroku-rust-cargo-hello `pwd`/cache

# Then make sure there are no Rust-related *.so files getting linked:
ldd heroku-rust-cargo-hello/target/hello

This gives you a system a lot like Heroku's Cedar stack, except that you can debug it locally.

Testing with Anvil

You can also test this buildpack using heroku-anvil, which is almost the same as Heroku's regular build environment.

heroku plugins:install https://github.com/ddollar/heroku-anvil
cd heroku-rust-cargo-hello
heroku build -b ../heroku-buildpack-rust