Would all those scenarios really be a part of a "unit" test? I generally approach unit tests to ensure that given pre-conditions of the "external structures" yo

Would all those scenarios really be a part of a "unit" test? I generally approach unit tests to ensure that given pre-conditions of the "external structures" you have a defined set of post-conditions that the test can exercise. The cases you've mentioned - I'd most likely leave up at integration & failure injection testing. Still handled by a CI/CD infrastructure but done at a level where the availability of an entire environment (DBs, multiple nodes, h/w, etc.) can be expected.