Ruby

What the generated Dockerfile does for a Ruby project, when you set no build or start command.

Base image. The image is ruby:<version>-slim.

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The Ruby Dockerfile

The defaults

Step	What Ferry does
Base image	The base image is `ruby:<version>-slim`. The version comes from `.ruby-version` or from the `ruby` line of the Gemfile. The default is 3.3.
System tools	`build-essential`, `git`, `libpq-dev`, `libyaml-dev` and `pkg-config`. Gems with native extensions need them.
Dependencies	`bundle install`
Build	None by default. Your build command runs after the install.
Start	With a `config.ru`: the command below.

The default start command

bundle exec rackup -o 0.0.0.0 -p ${PORT:-10000}

Rust

What the generated Dockerfile does for a Rust project, when you set no build or start command.

Start command

The start command starts your app in each container. Ferry finds it in three places, in order.