Enabling SSL by adding ssl_* doesn't work

[Chris Johnston]

When enabling SSL on rev50 by providing a certificate, the charm fails:

juju config grafana ssl_key="$(base64 -w 0 < grafana.maas.com_server.key.insecure)"
juju config grafana ssl_cert="$(base64 -w 0 < grafana.maas.com_server.crt)"
juju config grafana ssl_ca="$(base64 -w 0 < grafana.maas.com_server.crt)"

Unit Workload Agent Machine Public address Ports Message
grafana/0* error idle 5 172.27.248.168 3000/tcp hook failed: "config-changed"

2021-10-14 02:46:37 WARNING config-changed Traceback (most recent call last):
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/charm/hooks/config-changed", line 22, in <module>
2021-10-14 02:46:37 WARNING config-changed main()
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/charms/reactive/__init__.py", line 74, in main
2021-10-14 02:46:37 WARNING config-changed bus.dispatch(restricted=restricted_mode)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 390, in dispatch
2021-10-14 02:46:37 WARNING config-changed _invoke(other_handlers)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 359, in _invoke
2021-10-14 02:46:37 WARNING config-changed handler.invoke()
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 181, in invoke
2021-10-14 02:46:37 WARNING config-changed self._action(*args)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/charm/reactive/grafana.py", line 682, in configure_sources
2021-10-14 02:46:37 WARNING config-changed generate_prometheus_dashboards(gf_adminpasswd, ds)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/charm/reactive/grafana.py", line 988, in generate_prometheus_dashboards
2021-10-14 02:46:37 WARNING config-changed current_dashboards = get_current_dashboards(config["port"], gf_adminpasswd)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/charm/reactive/grafana.py", line 828, in get_current_dashboards
2021-10-14 02:46:37 WARNING config-changed verify=get_ca_cert_path(),
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/requests/api.py", line 76, in get
2021-10-14 02:46:37 WARNING config-changed return request('get', url, params=params, **kwargs)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/requests/api.py", line 61, in request
2021-10-14 02:46:37 WARNING config-changed return session.request(method=method, url=url, **kwargs)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/requests/sessions.py", line 530, in request
2021-10-14 02:46:37 WARNING config-changed resp = self.send(prep, **send_kwargs)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/requests/sessions.py", line 643, in send
2021-10-14 02:46:37 WARNING config-changed r = adapter.send(request, **kwargs)
2021-10-14 02:46:37 WARNING config-changed File "/var/lib/juju/agents/unit-grafana-0/.venv/lib/python3.6/site-packages/requests/adapters.py", line 514, in send
2021-10-14 02:46:37 WARNING config-changed raise SSLError(e, request=request)
2021-10-14 02:46:37 WARNING config-changed requests.exceptions.SSLError: HTTPSConnectionPool(host='127.0.0.1', port=3000): Max retries exceeded with url: /api/search?type=dash-db (Caused by SSLError(CertificateError("hostname '127.0.0.1' doesn't match 'grafana.maas.com'",),))

get_current_dashboards (among others) hard code the address as 127.0.0.1 [1].

[1] https://git.launchpad.net/charm-grafana/tree/src/reactive/grafana.py#n820