Ruby

You can see an example of configuring and using Ruby and Bundler with Batect in the Ruby sample project.

Example configuration

batect.yml

containers:
  build-env:
    image: ruby:2.7.2
    volumes:
      - local: .
        container: /code
      - type: cache
        name: bundle-cache
        container: /bundle-cache
    working_directory: /code
    environment:
      BUNDLE_PATH: /bundle-cache

Caching dependencies

tip

tl;dr: Mount a cache as the BUNDLE_PATH directory within the container, otherwise you'll have to download your dependencies every time the build runs

By default, Bundler downloads all of your application's dependencies to the directory set by the BUNDLE_PATH environment variable. However, because Batect destroys all of your containers once the task finishes, this directory is lost at the end of every task run - which means that Bundler will have to download all of your dependencies again, significantly slowing down the build.

The solution to this is to set BUNDLE_PATH and mount a cache into the container at that path, so that these downloaded dependencies are persisted between builds.

The example configuration above demonstrates how to do this.