flannel cannot be installed on jammy

[Jeff Hillman]

22.04.1
flannel:
  charm: flannel
  series: jammy
  channel: stable

When attempting to install flannel on a jammy instance, the following error occurs during the install hook:

```

   error: subprocess-exited-with-error

   × python setup.py egg_info did not run successfully.
   │ exit code: 1
   ╰─> [1 lines of output]
       error in Tempita setup command: use_2to3 is invalid.
       [end of output]

   note: This error originates from a subprocess, and is likely not a problem with pip.

error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.
Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-flannel-0/charm/hooks/install", line 8, in <module>
     basic.bootstrap_charm_deps()
  File "/var/lib/juju/agents/unit-flannel-0/charm/lib/charms/layer/basic.py", line 219, in bootstrap_charm_deps
     check_call([pip, 'install', '-U', reinstall_flag, '--no-index',
   File "/usr/lib/python3.10/subprocess.py", line 369, in check_call
     raise CalledProcessError(retcode, cmd)
 subprocess.CalledProcessError: Command '['/var/lib/juju/agents/unit-flannel-0/.venv/bin/pip', 'install', '-U', '--force-reinstall', '--no-index', '--no-cache-dir', '-f', 'wheelhouse', 'netaddr==0.7.19', 'dnspython==1.16.0', 'python-etcd==0.4.5', 'charms.reactive==1.5.0', 'Jinja2==2.11.3', 'pyaml==21.10.1', 'charmhelpers==0.20.24', 'urllib3==1.26.11', 'charms.templating.jinja2==1.0.2', 'six==1.16.0', 'PyYAML==5.3.1', 'pbr==5.9.0', 'Tempita==0.5.2']' returned non-zero exit status 1.

```

[George Kraft (cynerva)]

Thanks for the report. We'll get this fixed soon.

[George Kraft (cynerva)]

For context, this is caused by the charms.templating.jinja2 python package, which pins charmhelpers to an older version[1] that's missing the tempita fix[2]. We fixed the same issue in some of our other charms by removing the charms.templating.jinja2 package requirement from them. We probably just need to do the same for Flannel.

[1]: https://github.com/juju-solutions/charms.templating.jinja2/blob/b958f36c20eb46ce1b589e7e7c7f7deef658289e/requirements.txt#L2
[2]: https://github.com/juju/charm-helpers/pull/674

[Adam Dyess (addyess)]

While I've isolated the charm issue of installing, there seems to be a flaw within the jammy glibc runtime preventing jammy deployments of flannel.

See: https://github.com/flannel-io/flannel/issues/1512

[Adam Dyess (addyess)]

Charm Adjustments:
https://github.com/charmed-kubernetes/charm-flannel/pull/83

[Adam Dyess (addyess)]

Canal: https://github.com/charmed-kubernetes/layer-canal/pull/72
AWS-IAM: https://github.com/charmed-kubernetes/charm-aws-iam/pull/9

[George Kraft (cynerva)]

Canal follow-up PR: https://github.com/charmed-kubernetes/layer-canal/pull/73