Overview

Provides Rails generators to produce Dockerfiles and related files. This is being proposed as the generator to be included in Rails 7.1, and a substantial number of pull requests along those lines have already been merged. This repository contains fixes and features beyond those pull requests. Highlights:

• Supports all Rails supported releases, not just Rails 7.1, and likely works with a number of previous releases.
• Can be customized using flags on the generate dockerfile command, and rerun to produce a custom tailored dockerfile based on detecting the actual features used by your application.
• Can produce a docker-compose.yml file for locally testing your configuration before deploying.

Usage

bundle add dockerfile-rails --group development
bin/rails generate dockerfile

General options:

• --force - overwrite existing files
• --ci - include test gems in deployed image
• --platform=s - specify target platform. See FROM for details.
• --cache - use build caching to speed up builds
• --parallel - use multi-stage builds to install gems and node modules in parallel
• --compose - generate a docker-compose.yml file

Dependencies:

Generally the dockerfile generator will be able to determine what dependencies you are actually using. But should you be using DATABASE_URL, for example, at runtime additional support may be needed:

• --mysql - add mysql libraries
• --posgresql - add posgresql libraries
• --redis - add redis libraries
• --sqlite3 - add sqlite3 libraries

Optimizations:

• --fullstaq - use fullstaq images on quay.io
• --jemalloc - use jemalloc memory allocator
• --yjit - enable YJIT optimizing compiler
• --swap=n - allocate swap space. See falloc options for suffixes

Links:

• Demos
• Preparations for Rails 7.1
• Rails Dockerfile futures
• Fly Cookbooks
• app/templates/Dockerfile.tt