• Rust via rustup.
• x86_64-unknown-linux-musl Rust target: rustup target add x86_64-unknown-linux-musl
• cargo-make: cargo install cargo-make
• musl libc
  • Linux (Debian): sudo apt install musl-tools
  • MacOS via homebrew-musl-cross: brew install FiloSottile/musl-cross/musl-cross
• libssl-dev
  • Linux (Debian): sudo apt install libssl-dev
  • MacOS: brew install openssl
• pack (for local development)

This buildpack targets x86_64-unknown-linux-musl as the platform for the buildpack and comes with tooling to support cross-compilation on macOS. It uses libcnb.rs as the language binding for buildpacks.

To use this buildpack for local development that can be used by pack, a buildpack dir needs to be made:

$ cargo make pack

This will create a target/ directory that can be passed to pack. If a default builder hasn't been set, the heroku one can be set:

$ pack config default-builder heroku/buildpacks:20

With the heroku builder image set and from the buildpack directory:

$ pack build <IMAGE NAME> -b heroku/jvm -b heroku/maven -b `target` -p <APP SOURCE DIR>

cargo-make has the concept of profiles which is how it can choose where to do a "release" build with optimizations for runtime vs. optimizing for build speed.

When packaging up the buildpack the build.sh script uses this cargo-make command:

$ cargo make pack --profile production

To run the unit + doc tests:

$ cargo test

Licensed under the MIT License. See LICENSE file.