Builds

Railway uses Cloudnative Buildpacks to attempt to build and deploy with zero configuration. Currently, we support the following languages out of the box

• NodeJS
• Python
• Go
• Ruby
• Java

If you have a language that you want us to support, please don't hesitate to reach out and let us know.

We will also build using a Dockerfile if found at the project root.

Procfile

If your project use buildpacks, you specify the start command with a Procfile. A Procfile is in the format of

When Railway deploys your build, the process listed in the file will be started by running the respective command. Note: Railway can only execute one process per Procfile.

Note: some buildpacks specify a default start command

Web process

HTTP servers should use the web process type. This process should listen on the PORT environment variable and will receive HTTP traffic. For example,

Paketo Buildpacks

By default Railway will attempt to build your app with the heroku/buildpacks:20 builder, which is based on how Heroku builds apps. However, you can opt-in to build your app with the Paketo buildpacks. Paketo has support for

• NodeJS
• Go
• PHP
• Ruby
• Java
• .NET
• NGINX
• Python

Custom Buildpacks

By default, the appropriate buildpacks are selected by inspecting the source files of a project. For more control, a project.toml file can be used to achieve a more custom setup.

Here is an example project.toml file that forces a NodeJS project to use Yarn instead of NPM.

Nixpacks

Nixpacks is an opensource, drop in replacement for the cloud native buildpacks

Once in Priority Boarding, you should be able to enable it inside of Service -> Settings -> Builder

Issues? Report them on GitHub