App, Role, and Env
There are 3 env variables that ufo uses that are good to know.
| Name | Default | Description |
|---|---|---|
| UFO_ENV | dev | The environment like dev or prod. |
| UFO_APP | nil | This is nil by default because it’s usually configured with config.app in .ufo/config.rb, which makes UFO_APP optional. |
| UFO_ROLE | web | The role like web, worker, or clock. |
They are all env vars optional. Next, we’ll cover the variables in an order that helps learning.
UFO_ENV
This is pretty straightforward. You can use this to create and deploy different environments. Example:
UFO_ENV=dev ufo ship
UFO_ENV=prod ufo ship
UFO_ROLE
The role is a concept inspired from heroku. Apps often have a notion of a web, worker, and clock role. The default role is web. For example, if you configured an app name of demo like so:
.ufo/config.rb
Ufo.configure do |config|
config.app = "demo"
end
Since the default is UFO_ROLE=web, running
ufo ship
Creates a demo-web-dev stack. The role is in the middle, IE: demo-:ROLE-dev. You can switch roles like so:
UFO_ROLE=worker ufo ship
UFO_ROLE=clock ufo ship
This will create demo-worker-dev and demo-clock-dev stacks, respectively.
UFO_APP
The UFO_APP is the last one to cover and is interesting because you usually configure the app in .ufo/config.rb with config.app = "demo". The UFO_APP variable allows you to override the app and activates app-level layering. This allows you to use the Central Deploy Pattern. When using UFO_APP, there’s no need to configure config.app.