Calico fails with "cni-relation-changed"

[Bas de Bruijne]

In testrun https://solutions.qa.canonical.com/v2/testruns/12fc360e-61e2-4f31-9776-f36d7d949bea, calico fails with:

```
kubernetes-worker/1 active idle 1 10.244.8.132 80/tcp,443/tcp Kubernetes worker running (without gpu support).
  calico/2 error idle 10.244.8.132 hook failed: "cni-relation-changed"
  containerd/2 active idle 10.244.8.132 Container runtime available
  nrpe/7 blocked idle 10.244.8.132 Nagios server not configured or related
kubernetes-worker/2 active idle 2 10.244.8.129 80/tcp,443/tcp Kubernetes worker running.
  calico/3 waiting idle 10.244.8.129 Waiting to retry disabling VXLAN TX checksumming
  containerd/3 active idle 10.244.8.129 Container runtime available
  nrpe/10 blocked idle 10.244.8.129 Nagios server not configured or related
```

In the calico logs we see:
```
unit-calico-2: 20:06:32 DEBUG unit.calico/2.juju-log cni:12: Writing file /lib/systemd/system/calico-node.service root:root 444
unit-calico-2: 20:06:32 WARNING unit.calico/2.cni-relation-changed Created symlink /etc/systemd/system/multi-user.target.wants/calico-node.service → /lib/systemd/system/calico-node.service.
unit-calico-2: 20:06:33 DEBUG unit.calico/2.juju-log cni:12: tracer: cleared flag cni.kubeconfig.changed
unit-calico-2: 20:06:33 DEBUG unit.calico/2.juju-log cni:12: tracer>
tracer: set flag calico.service.installed
tracer: ++ queue handler reactive/calico.py:172:check_etcd_changes
tracer: ++ queue handler reactive/calico.py:666:disable_vxlan_tx_checksumming
tracer: -- dequeue handler reactive/calico.py:248:install_calico_service
unit-calico-2: 20:06:33 INFO unit.calico/2.juju-log cni:12: Invoking reactive handler: reactive/calico.py:484:configure_node
unit-calico-2: 20:06:33 INFO unit.calico/2.juju-log cni:12: status-set: maintenance: Configuring Calico node
unit-calico-2: 20:06:41 ERROR unit.calico/2.juju-log cni:12: Hook error:
Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/charms/reactive/__init__.py", line 74, in main
    bus.dispatch(restricted=restricted_mode)
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 390, in dispatch
    _invoke(other_handlers)
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 359, in _invoke
    handler.invoke()
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/charms/reactive/bus.py", line 181, in invoke
    self._action(*args)
  File "/var/lib/juju/agents/unit-calico-2/charm/reactive/calico.py", line 494, in configure_node
    node = calicoctl_get('node', node_name)
  File "/var/lib/juju/agents/unit-calico-2/charm/reactive/calico.py", line 685, in calicoctl_get
    result = yaml.safe_load(output)
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/yaml/__init__.py", line 162, in safe_load
    return load(stream, SafeLoader)
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/yaml/__init__.py", line 114, in load
    return loader.get_single_data()
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/yaml/constructor.py", line 49, in get_single_data
    node = self.get_single_node()
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/yaml/composer.py", line 39, in get_single_node
    if not self.check_event(StreamEndEvent):
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
  File "/var/lib/juju/agents/unit-calico-2/.venv/lib/python3.8/site-packages/yaml/parser.py", line 171, in parse_document_start
    raise ParserError(None, None,
yaml.parser.ParserError: expected '<document start>', but found '<block mapping start>'
  in "<byte string>", line 2, column 1:
    apiVersion: projectcalico.org/v3
    ^
```

It looks like the calico get node output is different than expected, I'm not sure why this is happening.

Crashdumps and configs can be found here:
https://oil-jenkins.canonical.com/artifacts/12fc360e-61e2-4f31-9776-f36d7d949bea/index.html

[George Kraft (cynerva)]

Looks like the same issue as https://bugs.launchpad.net/charm-calico/+bug/1990672. I've marked this as a duplicate.