import error packagefinder on focal

[Adam Stokes]

Attempting to deploy flannel on focal with ck 1.18 results in flannel workload error:

unit-kubernetes-worker-1: 03:51:03 DEBUG unit.kubernetes-worker/1.juju-log kube-control:6: tracer: set flag config.default.allow-privileged
unit-kubernetes-master-0: 03:51:03 DEBUG unit.kubernetes-master/0.juju-log tracer: set flag config.set.image-registry
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm Traceback (most recent call last):
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/var/lib/juju/agents/unit-flannel-1/.venv/bin/pip", line 5, in <module>
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm from pip._internal import main
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/var/lib/juju/agents/unit-flannel-1/.venv/lib/python3.8/site-packages/pip/_internal/__init__.py", line 40, in <module>
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm from pip._internal.cli.autocompletion import autocomplete
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/var/lib/juju/agents/unit-flannel-1/.venv/lib/python3.8/site-packages/pip/_internal/cli/autocompletion.py", line 8, in <module>
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm from pip._internal.cli.main_parser import create_main_parser
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/var/lib/juju/agents/unit-flannel-1/.venv/lib/python3.8/site-packages/pip/_internal/cli/main_parser.py", line 12, in <module>
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm from pip._internal.commands import (
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/var/lib/juju/agents/unit-flannel-1/.venv/lib/python3.8/site-packages/pip/_internal/commands/__init__.py", line 6, in <module>
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm from pip._internal.commands.completion import CompletionCommand
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/var/lib/juju/agents/unit-flannel-1/.venv/lib/python3.8/site-packages/pip/_internal/commands/completion.py", line 6, in <module>
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm from pip._internal.cli.base_command import Command
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/var/lib/juju/agents/unit-flannel-1/.venv/lib/python3.8/site-packages/pip/_internal/cli/base_command.py", line 23, in <module>
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm from pip._internal.index import PackageFinder
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm ImportError: cannot import name 'PackageFinder' from 'pip._internal.index' (/var/lib/juju/agents/unit-flannel-1/.venv/lib/python3.8/site-packages/pip/_internal/index/__init__.py)
unit-kubernetes-master-1: 03:51:03 DEBUG unit.kubernetes-master/1.juju-log certificates:7: tracer: set flag config.set.dashboard-auth
unit-kubernetes-worker-1: 03:51:03 DEBUG unit.kubernetes-worker/1.juju-log kube-control:6: tracer: set flag config.set.channel
unit-etcd-2: 03:51:03 DEBUG unit.etcd/2.juju-log tracer: set flag config.default.port
unit-kubernetes-worker-0: 03:51:03 INFO unit.kubernetes-worker/0.juju-log certificates:10: Invoking reactive handler: reactive/kubernetes_worker.py:1164:missing_kube_control
unit-kubernetes-master-0: 03:51:03 DEBUG unit.kubernetes-master/0.juju-log tracer: set flag config.default.image-registry
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm Traceback (most recent call last):
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/var/lib/juju/agents/unit-flannel-1/charm/hooks/upgrade-charm", line 8, in <module>
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm basic.bootstrap_charm_deps()
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "lib/charms/layer/basic.py", line 170, in bootstrap_charm_deps
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm check_call([pip, 'install', '-U', '--no-index', '-f', 'wheelhouse',
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm File "/usr/lib/python3.8/subprocess.py", line 364, in check_call
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm raise CalledProcessError(retcode, cmd)
unit-flannel-1: 03:51:03 DEBUG unit.flannel/1.upgrade-charm subprocess.CalledProcessError: Command '['/var/lib/juju/agents/unit-flannel-1/.venv/bin/pip', 'install', '-U', '--no-index', '-f', 'wheelhouse', 'pip']' returned non-zero exit status 1.

[Cory Johns (johnsca)]

Per https://github.com/pypa/pip/issues/7620 it seems like there was an issue with the 20.0 release of pip. Focal seems to be on 20.0.2, but it seems that there's stilll an issue with it:

$ lxc launch ubuntu-daily:focal
Creating the instance
Instance name is: good-hawk
Starting good-hawk
$ lxc shell good-hawk
root@good-hawk:~# apt update
...
root@good-hawk:~# apt install python3-pip
...
root@good-hawk:~# pip3 --version
WARNING: pip is being invoked by an old script wrapper. This will fail in a future version of pip.
Please see https://github.com/pypa/pip/issues/5599 for advice on fixing the underlying issue.
To avoid this problem you can invoke Python with '-m pip' instead of running pip directly.
pip 20.0.2 from /usr/lib/python3/dist-packages/pip (python 3.8)

[Cory Johns (johnsca)]

It turns out that the pip, setuptools, and setuptools-scm bundling in layer:basic ends up downgrading these packages on Focal causing this issue, but only after the initial bootstrap. Flannel seems to run an upgrade-charm during the initial install for some reason, which is why we're seeing this on this charm and not others, but it will affect all reactive charms on Focal at the first upgrade.

I filed this against layer:basic at https://github.com/juju-solutions/layer-basic/issues/159 and have a PR in progress to address this at https://github.com/juju-solutions/layer-basic/pull/160

[Cory Johns (johnsca)]

The PR has been merged.

[George Kraft (cynerva)]

Cherry-pick to stable:
https://github.com/charmed-kubernetes/layer-basic/commit/4761d6c966966441b8eb388af152b25ddcde6636
https://github.com/charmed-kubernetes/layer-basic/commit/a7ad4f1f6fddc6c767549c29a77f341c2dccacbf
https://github.com/charmed-kubernetes/layer-basic/commit/955e85312718dbc3818e471dc7c3ea983cb09ce8

[George Kraft (cynerva)]

Follow-up cherry-pick due to an issue encountered in testing:
https://github.com/charmed-kubernetes/layer-basic/commit/f761da8d4a2985b725f2ec79be703f3e63b0e29b

[George Kraft (cynerva)]

No cherry-pick needed for keepalived 1.20+ck1 release.