feat: integrate with Prometheus and Grafana charms

[amandahla]

Applicable spec:

Overview

Add integration between Maubot and Grafana/Prometheus.

Maubot does not provide a /metrics endpoints that Prometheus could read so Blackbox Prometheus Exporter was installed to collect data.

Why the trivial label? It's a large PR but nothing unusual.

Dashboard screenshot:

Rationale

Monitor Maubot application.

Juju Events Changes

Module Changes

Library Changes

Grafana and Prometheus libraries.

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated
• The PR is tagged with appropriate label (urgent, trivial, complex)

No CH available

[github-actions]

Remaining comments which cannot be posted as a review comment to avoid GitHub Rate Limit

Inclusive naming check

---

[Inclusive naming check] _{reported by reviewdog 🐶}
[error] blackbox may be insensitive, use closed-box instead

maubot-operator/src/grafana_dashboards/maubot.json

Line 1174 in 48698be

"blackbox",

---

[Inclusive naming check] _{reported by reviewdog 🐶}
[error] Blackbox may be insensitive, use closed-box instead

maubot-operator/src/grafana_dashboards/maubot.json

Line 1362 in 48698be

"title": "Prometheus Maubot Blackbox Exporter",

[github-actions]

license-eye has checked 44 files.

Valid	Invalid	Ignored	Fixed
11	1	32	0

Click to see the invalid file list

• maubot_rock/blackbox.yaml

Use this command to fix any missing license headers

```bash

docker run -it --rm -v $(pwd):/github/workspace apache/skywalking-eyes header fix

</details>

[github-actions]

license-eye has checked 45 files.

Valid	Invalid	Ignored	Fixed
11	2	32	0

Click to see the invalid file list

• .woke.yaml
• maubot_rock/blackbox.yaml

Use this command to fix any missing license headers

```bash

docker run -it --rm -v $(pwd):/github/workspace apache/skywalking-eyes header fix

</details>

[cbartz]

LGTM, have some nit comments.

[github-actions]

Test coverage for af9ca6e

Name           Stmts   Miss Branch BrPart  Cover   Missing
----------------------------------------------------------
src/charm.py     144     11     22      6    90%   137-139, 158, 162, 184, 188, 206, 233, 238, 263
----------------------------------------------------------
TOTAL            144     11     22      6    90%

Static code analysis report

Run started:2024-10-14 20:44:57.705981

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 668
  Total lines skipped (#nosec): 0
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):

[merkata]

🚀