Layering Basics


Variables support layering. Here’s a simple starter layers structure:

├── base.rb
├── dev.rb
└── prod.rb

Your task definition like .ufo/resources/task_definitions/web.json is processed by ERB templating and can make of variables.

With layering, you can set and use common base.rb variables for your task definitions. And then override env specific values like so:

export UFO_ENV=dev
ufo ship # uses .ufo/vars/base.rb and .ufo/vars/dev.rb

For prod:

export UFO_ENV=prod
ufo ship # uses .ufo/vars/base.rb and .ufo/vars/prod.rb
  • base.rb is always evaluated.
  • dev.rb or prod.rb is evaluated based on UFO_ENV.


More step-by-step docs are provided in the following documentation pages and details layering further.