Fix/linting

[merkata]

This PR fixes linting issues found by mypy and pylint linters that are run via tox -e lint.

[arturo-seijas]

I'm afraid you'll need to remove ops.testing.CAN_CONNECTinstead of ignoring the linting error. This is the default behaviour in ops 2

[arturo-seijas]

LGTM

[jdkandersson]

Thanks for tackling the linting and typing issues!

[arturo-seijas]

LGTM

[github-actions]

Test coverage for 94489c9

Name           Stmts   Miss Branch BrPart  Cover   Missing
----------------------------------------------------------
src/charm.py     180     21     56      4    88%   279->283, 376-377, 404-406, 428-432, 441-452, 463->exit, 478-480
----------------------------------------------------------
TOTAL            180     21     56      4    88%

Static code analysis report

Run started:2023-01-31 12:34:58.733016

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 1196
  Total lines skipped (#nosec): 4
  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):

[arturo-seijas]

LGTM

[amandahla]

LGTM but it seems that trivy config was not found.

https://github.com/canonical/discourse-k8s-operator/actions/runs/4054111097/jobs/6975542344

Example of output in Indico:

"-a image" "-b table" "-c " "-d 1" "-e false" "-f os,library" "-g CRITICAL,HIGH" "-h " "-i ghcr.io/canonical/indico:4073362325" "-j ." "-k " "-l " "-m " "-n " "-o " "-p " "-q " "-r false" "-s " "-t " "-u " "-v trivy.yaml" "-z "
Running Trivy with trivy.yaml config from:  trivy.yaml

[merkata]

LGTM but it seems that trivy config was not found.

https://github.com/canonical/discourse-k8s-operator/actions/runs/4054111097/jobs/6975542344

Example of output in Indico:

"-a image" "-b table" "-c " "-d 1" "-e false" "-f os,library" "-g CRITICAL,HIGH" "-h " "-i ghcr.io/canonical/indico:4073362325" "-j ." "-k " "-l " "-m " "-n " "-o " "-p " "-q " "-r false" "-s " "-t " "-u " "-v trivy.yaml" "-z "
Running Trivy with trivy.yaml config from:  trivy.yaml

It's part of a different PR, now everything is in place and I can update the chaos one that will have trivy, passing linters and jira action step. Thanks!