rec: Upgrade regression tests to use pytest instead of nose

[omoerbeek]

One mysterious failure on Debian bookworm spotted: test_EDNS.py does not seem to set the right edns version on the outgoing query. To be investigated.

Short description

Checklist

I have:

• read the CONTRIBUTING.md document
• compiled this code
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)

[omoerbeek]

This code (from pythons dns package in message.py):

   def want_dnssec(self, wanted: bool = True) -> None:
        """Enable or disable 'DNSSEC desired' flag in requests.

        *wanted*, a ``bool``.  If ``True``, then DNSSEC data is
        desired in the response, EDNS is enabled if required, and then
        the DO bit is set.  If ``False``, the DO bit is cleared if
        EDNS is enabled.
        """

        if wanted:
            self.ednsflags |= dns.flags.DO
        elif self.opt:
            self.ednsflags &= ~dns.flags.DO

Does seem to behave differently on python 3.11 compared to 3.9.
On 3.11 the flags gets reset to 0 if wanted is False

[omoerbeek]

Reproducer:

import enum

class EDNSFlag(enum.IntFlag):
    #: DNSSEC answer OK
    DO = 0x8000

x = 0xffffffff

print(x)
x &= ~EDNSFlag.DO
print(x)

on a python 3.8 system and a 3.10 system:

4294967295
EDNSFlag.2147483648|1073741824|536870912|268435456|134217728|67108864|33554432|16777216|8388608|4194304|2097152|1048576|524288|262144|131072|65536|16384|8192|4096|2048|1024|512|256|128|64|32|16|8|4|2|1

On a python 3.11.2 system:

4294967295
32767

Note that 32767 = 0x7fff

[peterthomassen]

There seem to be differences in flag handling between Python 3.11.3 and 3.11.4 (python/cpython#105497). Which 3.11 minor version are you testing on?

[omoerbeek]

There seem to be differences in flag handling between Python 3.11.3 and 3.11.4 (python/cpython#105497). Which 3.11 minor version are you testing on?

3.11.2 (also edited above)

[omoerbeek]

BTW, setting this PR to be ready for review. The python shenanigans are unrelated to the move to pytest.

[omoerbeek]

Output on a python 3.11.4 system:

4294967295
4294934527

4294934527 = 0xffff7fff, which looks good.

[zeha]

doesn't seem quite right:

  - generated xml file: /__w/pdns/pdns/regression-tests.recursor-dnssec/pytest.xml -
  ================= 441 passed, 6 warnings in 490.86s (0:08:10) ==================
  + ./printlogs.py
  Traceback (most recent call last):
    File "/__w/pdns/pdns/regression-tests.recursor-dnssec/./printlogs.py", line 8, in <module>
      e = xml.etree.ElementTree.parse('nosetests.xml')
    File "/usr/lib/python3.9/xml/etree/ElementTree.py", line 1229, in parse
      tree.parse(source, parser)
    File "/usr/lib/python3.9/xml/etree/ElementTree.py", line 569, in parse
      source = open(source, "rb")
  FileNotFoundError: [Errno 2] No such file or directory: 'nosetests.xml'

[omoerbeek]

FileNotFoundError: [Errno 2] No such file or directory: 'nosetests.xml'

Fixed, thanks!

[omoerbeek]

Added code that skip the tests on specific python versions:

if sys.version_info >= (3, 11) and sys.version_info <= (3, 11, 3):
            raise SkipTest("Test skipped, see https://github.com/PowerDNS/pdns/pull/12912")

[rgacogne]

Bad news, this seems broken on 3.11.5 again:

$ python badvers.py
4294967295
32767