Description

PR #38543 added support for runtime app environments, mentioning use cases such as loading an app with production configurations but with different sets of environment variables. However, the DotEnv component uses APP_ENV by default to locate and load various .env files.

I propose it should use APP_RUNTIME_ENV by default and fall back to APP_ENV to locate and load .env files. This would ensure consistent loading of environment variables, regardless of whether they are encrypted (secrets) or not.

At the moment, APP_RUNTIME_ENV alone isn't sufficient. Consider a scenario where one wants to use Mailgun for production and Mailpit for staging environments (using the same Symfony configuration, i.e., APP_ENV=prod for both). One would expect APP_RUNTIME_ENV=uat php bin/console secrets:decrypt-to-local --force to work, but it won't, as .env.uat.local will never be loaded. This is because APP_ENV is set to prod and DotEnv::bootEnv() will only load .env.prod and .env.prod.local.

Example

• Current behavior:
  If APP_ENV=prod and APP_RUNTIME_ENV=uat, it will load .env, .env.prod, and .env.prod.local.

• Proposed behavior:
  If APP_ENV=prod and APP_RUNTIME_ENV=uat, it will load .env, .env.uat, and .env.uat.local.