Use Docker images as build environments hosted on other registries

[Vadim Sherstiuk]

In pipeline steps I used many variables also for authorization on the Azure container repository like below:

- step: &run-tests
    name: Run unit tests
      image:
        name: docker.your-company-name.com/python_unixodbc:3.8.2
        username: $USERNAME
        password: $PASSWORD
      script:
        - ...

But for consistency, I wanted to wrap all variables in curly braces. Bitbucket supports this syntax and I have not seen any problems before.... until today. Turns out I can't use the wrapped in curly braces username and password variables used for authorization to other container repositories.

I hope this helps someone. So use the official documentation :)