feat: add NGINX rock

[amandahla]

Applicable spec:

Overview

This PR adds a NGINX rock and pebble layer to the Maubot charm.

Rationale

NGINX will act as a proxy.

Note:

• PRs feat: add PostgreSQL integration #7 and feat: add Ingress integration #8 will add Ingress and PostgreSQL , providing the actual Maubot application.
• Further PR will change Maubot layer to run under daemon user, set IngressRequires properly and also add an integration test for checking the URL.

Juju Events Changes

Add NGINX pebble ready event.

Module Changes

Library Changes

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]

Test coverage for 7c71c7b

Name           Stmts   Miss Branch BrPart  Cover   Missing
----------------------------------------------------------
src/charm.py      59     21     10      2    58%   50, 57-63, 67-72, 76-81, 87
----------------------------------------------------------
TOTAL             59     21     10      2    58%

Static code analysis report

Run started:2024-09-17 14:55:59.752612

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 210
  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):

[weiiwang01]

I think the overall is great, but I have one question related to this: why not include nginx in the maubot image and use pebble to run both the maubot service and nginx in the same container? Is there any reason for using two containers?

[weiiwang01]

nit: probably don't need to compress PNG files.

[weiiwang01]

Maybe the access log should be logged to stdout, as the error log is logged to stderr?

[amandahla]

I think the overall is great, but I have one question related to this: why not include nginx in the maubot image and use pebble to run both the maubot service and nginx in the same container? Is there any reason for using two containers?

Thats an excellent question. I cant think of any reason for having two containers!

[amandahla]

I'll close this PR and add NGINX to Maubot. Thanks @weiiwang01 !