DIP: use .env variables in your dip.yml configuration

As stated in my post Keeping histories in dip provision:

I’ve found no way to use the env var in the yaml. (therefore I’m hardcoding it in the dip.yml)

There is an temporary solution by leveraging ERB in yaml. This way we can load the .env (which is also used by docker compose itself) and use vars defined there in our dip configuration:

• By loading the dotenv gem inside the YAML
• These snippets make sure that there is a default value (e.g. api)
  • dip.yml: docker volume create <%= ENV.fetch('COMPOSE_PROJECT_NAME', 'api') %>
  • docker-comose.yml: name: ${COMPOSE_PROJECT_NAME:-api}-history

The next step would be a PR agains the dip gem but that is for another day.

dip.yml

<%
begin
  require "dotenv"
  Dotenv.load
  puts "🎉 Dotenv loaded!"
rescue LoadError
  puts "🚨 Dotenv not loaded, ignoring '.env' files"
end
%>
#...
provision:
  - dip compose down --volumes --remove-orphans
  - docker volume create <%= ENV.fetch('COMPOSE_PROJECT_NAME', 'api') %>-history
  ...

docker-compose.yml

volumes:
  history:
    external: true
    name: ${COMPOSE_PROJECT_NAME:-api}-history