Add a test case to check for lingering TCP sockets stuck in the
CLOSE_WAIT state. This can happen if a client sends some garbage after
its first query.
The system test runs the reproducer script and then sends another TCP
query to the resolver. The resolver is configured to allow one TCP
client only. If BIND has its TCP socket stuck in CLOSE_WAIT, it does
not have the resources available to answer the second query.
Note: A better test would be to check if the named daemon does not
have a TCP socket stuck in CLOSE_WAIT for example with netstat. When
running this test locally you can examine named with netstat manually.
But since netstat is platform specific it is not a good candidate to do
this as a system test.
If you, if you could return, don't let it burn.
Do you have to let it linger?
- Cranberries
Ensure all "import dns.*" statements are always placed after
pytest.importorskip('dns') calls, in order to allow the latter to
fulfill their purpose. Explicitly import all dnspython modules used by
each dnspython-based test to avoid relying on nested imports. Replace
function-scoped imports with global imports to reduce code duplication.
The intended purpose of the @pytest.mark.dnspython{,2} decorators was to
cause dnspython-based tests to be skipped if dnspython is not available
(or not recent enough). However, a number of system tests employing
those decorators contain global "import dns.resolver" statements which
trigger ImportError exceptions during test initialization if dnspython
is not available. In other words, the @pytest.mark.dnspython{,2}
decorators serve no useful purpose.
Currently, whenever a Python-based test requires dnspython, that
requirement applies to all tests in a given *.py file. Given that,
employ global pytest.importorskip() calls to ensure dnspython-based
parts of various system tests are skipped when dnspython is not
available. Remove all occurrences of the @pytest.mark.dnspython{,2}
decorators (and all associated code) to prevent confusion.
Most Python-based system tests need to know which ports were assigned to
a given test by bin/tests/system/get_ports.sh. This is currently
handled by inspecting the values of various environment variables (set
by bin/tests/system/run.sh) and passing the port numbers to Python
scripts via pytest fixtures. However, this glue code has so far been
copy-pasted into each system test using it, rather than reused.
Since pytest also looks for conftest.py files in parent directories,
move commonly used fixtures to bin/tests/system/conftest.py. Set the
scope of all the moved fixtures to "session" as their return values are
only based on environment variables, so there is no point in recreating
them for every test requesting them. Adjust test code accordingly.
