The OpenStack-style cloud-init endpoints (index, meta_data.json,
user_data) are fetched by booting VMs, which do not log in. Since the
login-required middleware they redirected to the login page, so the
datasource has not worked. They are login_not_required now; they expose
a hostname and the public SSH keys of a VM's owners.
A VM is found by the reverse DNS name of the client address, and VM
names are not unique (only compute and UUID are). user_data merged the
owners of every VM with that name, so a user who named their VM like
another user's VM got their key into that VM at its next cloud-init
run. Keys are now given only when exactly one VM has the name.
The client address is the last X-Forwarded-For entry, which nginx in
the default setup appends; gunicorn listens on 127.0.0.1 only. The bare
except around the reverse lookup is narrowed to OSError.
Super-linter ran from the unpinned :latest image and, because of
branches-ignore: [master], never on pull requests to master. Ruff now
checks syntax errors and pyflakes rules (E9, F) on every push and PR.
Fixes the existing findings: unused imports and variables, an unused
duplicate import in instances/tests.py, and the star import in
accounts/views.py. settings-dev.py keeps its star import of the base
settings.
