Ruby

Common Settings

The section outlines common settings and behaviours for Ruby projects.

Ruby Version

The Ruby version is automatically detected from .ruby-version file in the root directory of your project and the appropriate image is selected according to it.

To use a different version of Ruby other than the default, create a .ruby-version file and add the version to it. Example,

3.4.4

Ensure you use a version supported by docker ruby image.

Ruby on Rails

Rails builds on Viduli use separate build and run images.

• Base distribution: Debian 12 Bookworm Slim
• Default Ruby version: 3.4.4
• Default image:
  • Build: ruby:3.4.4-slim-bookworm
  • Runtime: ruby:3.4.4-slim-bookworm
• Included packages:
  • Base: curl libjemalloc2 libvips sqlite3
  • Build: build-essential git libyaml-dev pkg-config
• Default port: 3000

Build dependencies

Dependencies are installed using Bundler. The build process:

1. Installs application gems from Gemfile
2. Precompiles bootsnap code for faster boot times
3. Precompiles assets for production (using a dummy SECRET_KEY_BASE)

Build command

No explicit build command is run by default. Asset precompilation happens automatically during the build stage.

Runtime dependencies

Only production gems are included in the runtime image. Development and test dependencies are excluded.

Run command

The default is ./bin/rails server -b 0.0.0.0 -p 3000. It can be overridden by providing the run command in the resource build configuration.

Environment

The following environment variables are set:

• RAILS_ENV=production - Production environment
• BUNDLE_DEPLOYMENT=1 - Deployment mode
• BUNDLE_PATH=/usr/local/bundle - Bundle path
• BUNDLE_WITHOUT=development - Exclude development gems
• PORT=3000 - Application port

If you set a RAILS_RELATIVE_URL_ROOT secret, it will be available as an environment variable for Rails to use.

By default, PORT is set to 3000. If you set an expose port value in the resource build configuration, PORT is set to that value.

Secrets added to the resource are also available in the environment during the image build and run stages.

Entrypoint

The entrypoint script enables jemalloc for reduced memory usage and latency.

Note: Unlike the default entrypoint provided by the rails project, Viduli's entry script does not prepare the database prior to running the Rails server.

Sinatra

Sinatra builds on Viduli use a single build and run image.

• Base distribution: Debian 12 Bookworm Slim
• Default Ruby version: 3.4.4
• Default image: ruby:3.4.4-slim-bookworm
• Included packages: build-essential ca-certificates tzdata libffi-dev libyaml-dev
• Default port: 4567

Build dependencies

Dependencies are installed using Bundler and gem install. The build process:

1. Installs sinatra, rackup, puma, and bundler as system gems
2. Configures bundler for deployment mode
3. Installs gems from Gemfile if it exists

Build command

No explicit build command is run by default.

Run command

The default is ruby ${APP_FILE} where APP_FILE defaults to app.rb. You can override this by providing the run command in the resource build configuration.

Environment

The following environment variables are set:

• APP_ENV=production - Production environment
• APP_FILE=app.rb - Application file

By default, PORT is set to 4567 (Sinatra's default). If you set an expose port value in the resource build configuration, PORT is set to that value.

Secrets added to the resource are also available in the environment during the image build and run stages.

Ruby (Generic)

The generic Ruby build option is suitable for deploying projects that are not built using a supported Ruby framework. If your project uses a supported framework such as Rails or Sinatra, please select that option when deploying your project. By selecting the appropriate framework build, you get optimal settings that are not available when selecting the generic ruby option.

• Base distribution: Debian 12 Bookworm Slim
• Default Ruby version: 3.4.4
• Default image: ruby:3.4.4-slim-bookworm
• Included packages: build-essential ca-certificates tzdata libffi-dev libyaml-dev
• Default port: 3000

Build dependencies

Dependencies should be installed via your custom install command or using Bundler/Gemfile if present.

Build command

No explicit build command is run by default. You can set a custom build command in the resource build configuration.

Run command

You must provide a run command in the resource build configuration.

Environment

By default, PORT is set to 3000. If you set an expose port value in the resource build configuration, PORT is set to that value.

Secrets added to the resource are also available in the environment during the image build and run stages.