I really like the environment variables setup with the Angular CLI. One problem though is that sometime I need to pass to the app some keys or maybe some links that I do not want to commit on the repository (inside the environments.ts files, even if the repo is private).

Read about a innovative solution via using .env files to pass environment variables at building time in an Angular application https://medium.com/@ferie/how-to-pass-environment-variables-at-building-time-in-an-angular-application-using-env-files-4ae1a80383c