Name conflicts in environment variables

[pangui]

Hello,

I use DevContainer for all my projects, using a template setup, and always setting the database connection with DATABASE_URL environment variable.

Below is the env section for deploy.yml file I use:

env:
  clear:
    PORT: 3000
  secret:
    - RAILS_MASTER_KEY
    - DATABASE_URL
    - SENDGRID_API_KEY

For production environment I defined the corresponding DATABASE_URL value in .env.production file. Naturally, I want to use that value in production, however, when I run kamal env push -d production, the transferred value corresponds to the development system-wide definition instead of the production one. And this is the expected behavior since dotenv precedence works that way.

There are some workarounds. One option is to directly write the right value into the .kamal/env/my-service-production.env file using ssh. However, this makes env push command meaningless. I could also use database.yml locally and DATABASE_URL on the server. Write a script to temporarily redefine, push, and restore env var is another solution. Deploying using Github Actions can help too, but the main issue remains: there seems to be no way to use the same variable names on the environment that runs Kamal and the destination server.

I think a convenient alternative could be to include the env: file option in the deploy.[env].yml file, exclusively or in combination with current clear/secret options.

If you see any option to solve this with the current Kamal features and settings, I will be grateful for your comments.

Best!

Edit: script calling Dotenv.overload() Run as: bin/deploy_env push -d production

#!/usr/bin/env ruby
# frozen_string_literal: true

require 'thor'
require 'dotenv'

class DeployEnv < Thor

  desc 'push', 'Wrapper for kamal env push command'
  method_option :destination,
    aliases: '-d',
    required: true,
    desc: 'Specify destination for environment file (.env.[DESTINATION])'

  def push
    Dotenv.overload(".env.#{options[:destination]}")
    `kamal env push -d #{options[:destination]}`
  end

end
DeployEnv.start