Awesome  Rust

Awesome Rust


Heroku Buildpack for Rust

This is a Heroku buildpack for Rust with support for cargo and rustup. Features include:

  • Caching of builds between deployments.
  • Automatic updates to the latest stable Rust by default.
  • Optional pinning of Rust to a specific version.
  • Support for export so that other buildpacks can access the Rust toolchain.
  • Support for compiling Rust-based extensions for projects written in other languages.

Example projects

Here are several example projects:

Using this buildpack

To deploy an application to Heroku, we recommend installing the Heroku CLI.

If you're creating a new Heroku application, cd to the directory containing your code, and run:

heroku create --buildpack emk/rust

This will only work if your application has a Cargo.toml and uses git. If you want to set a particular name for application, see heroku create --help first.

To use this as the buildpack for an existing application, run:

heroku buildpacks:set emk/rust

You will also need to create a Procfile pointing to the release version of your application, and commit it to git:

web: ./target/release/hello

...where hello is the name of your binary.

To deploy your application, run:

git push heroku master

Running Diesel migrations during the release phase

This will install the diesel CLI at build time and make it available in your dyno. Migrations will run whenever a new version of your app is released. Add the following line to your RustConfig


and this one to your Procfile

release: ./target/release/diesel migration run

Specifying which version of Rust to use

By default, your application will be built using the latest stable Rust. Normally, this is pretty safe: New stable Rust releases have excellent backwards compatibility.

But you may wish to use nightly Rust or to lock your Rust version to a known-good configuration for more reproducible builds. To specify a specific version of the toolchain, use a rust-toolchain file in the format rustup uses.

Note: if you previously specified a VERSION variable in RustConfig, that will continue to work, and will override a rust-toolchain file.

Combining with other buildpacks

If you have a project which combines both Rust and another programming language, you can insert this buildpack before your existing one as follows:

heroku buildpacks:add --index 1 emk/rust

If you have a valid Cargo.toml in your project, this is all you need to do. The Rust buildpack will run first, and your existing buildpack will run second.

But if you only need Rust to build a particular Ruby gem, and you have no top-level Cargo.toml file, you'll need to let the buildpack know to skip the build stage. You can do this by adding the following line to RustConfig:


Customizing build flags

If you want to change the cargo build command, you can set the RUST_CARGO_BUILD_FLAGS variable inside the RustConfig file.

RUST_CARGO_BUILD_FLAGS="--release -p some_package --bin some_exe --bin some_bin_2"

The default value of RUST_CARGO_BUILD_FLAGS is --release. If the variable is not set in RustConfig, the default value will be used to build the project.

Using the edge version of the buildpack

The emk/rust buildpack from the Heroku Registry contains the latest stable version of the buildpack. If you'd like to use the latest buildpack code from this Github repository, you can set your buildpack to the Github URL:

heroku buildpacks:set

Development notes

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

Testing with Docker

To test changes to the buildpack using the included docker-compose-test.yml, run:


Then make sure there are no Rust-related *.so files getting linked:

ldd heroku-rust-cargo-hello/target/release/hello

This uses the Docker image heroku/cedar, which allows us to test in an official Cedar-like environment.

We also run this test automatically on Travis CI.

Download Details:
Author: emk
Source Code:

#rust  #rustlang  #deployment #heroku #buildpack 

Heroku Buildpack for Rust
Python  Library

Python Library


Heroku Buildpack for Python Apps

Heroku Buildpack: Python

This is the official Heroku buildpack for Python apps.

Recommended web frameworks include Django and Flask, among others. The recommended webserver is Gunicorn. There are no restrictions around what software can be used (as long as it's pip-installable). Web processes must bind to $PORT, and only the HTTP protocol is permitted for incoming connections.

See it in Action

$ ls
my-application        requirements.txt    runtime.txt

$ git push heroku main
Counting objects: 4, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (4/4), 276 bytes | 276.00 KiB/s, done.
Total 4 (delta 0), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote: -----> Python app detected
remote: -----> Installing python
remote: -----> Installing pip
remote: -----> Installing SQLite3
remote: -----> Installing requirements with pip
remote:        Collecting flask (from -r /tmp/build_c2c067ef79ff14c9bf1aed6796f9ed1f/requirements.txt (line 1))
remote:          Downloading ...
remote:        Installing collected packages: Werkzeug, click, MarkupSafe, Jinja2, itsdangerous, flask
remote:        Successfully installed Jinja2-2.10 MarkupSafe-1.1.0 Werkzeug-0.14.1 click-7.0 flask-1.0.2 itsdangerous-1.1.0
remote: -----> Discovering process types
remote:        Procfile declares types -> (none)

A requirements.txt must be present at the root of your application's repository to deploy.

To specify your python version, you also need a runtime.txt file - unless you are using the default Python runtime version.

Current default Python Runtime: Python 3.9.10

Alternatively, you can provide a file, or a Pipfile. Using pipenv will generate runtime.txt at build time if one of the field python_version or python_full_version is specified in the requires section of your Pipfile.

Specify a Buildpack Version

You can specify the latest production release of this buildpack for upcoming builds of an existing application:

$ heroku buildpacks:set heroku/python

Specify a Python Runtime

Supported runtime options include:

  • python-3.10.2
  • python-3.9.10
  • python-3.8.12
  • python-3.7.12

Download Details:
Author: heroku
Source Code:
License: MIT License

#python #heroku #buildpack

Heroku Buildpack for Python Apps