Extracting the discussion from #1848 to an issue.

With the move to v2 we should think of a strategy on how to test CLI commands and integration with plugins.

Some ideas from the PR on how to setup the tests:

1. Run Cobra commands directly via code
2. Invoke the CLI as an external process

Some ideas from the PR on how to assert the tests:

1. Snapshot CLI output (not included in the PR)
2. Assert other CLI command side effects, like generated configurations (already exists in our existing tests)

Dump any thoughts you have, for example https://medium.com/@sapegin/whats-wrong-with-snapshot-tests-37fbe20dfe8e