Description

This has been extracted from #2245 as it does not need to be part of that PR.

To function correctly, it depends on a helper-function.sh method added in #2274 , tests will pass once that is merged.

Mostly cleans up the code and documents it better, although there are some minor fixes for handling SSL_DOMAIN ENV and additional logging added for spotting issues related to it in future when troubleshooting.

Commits are scoped with context messages for easing review if necessary. Overview of changes:

Traefik specific:

• Logic extracted out into it's own function.
• Conditional reworked to assist with debugging.
• SSL_DOMAIN must not be empty when attempting to extract.
• Added additional notes.

SSL_TYPE=letsencrypt case:

• Revised top note block.
• Correct handling for SSL_DOMAIN.
• Removed some unnecessary nesting.
• Less repetitive error message for LETSENCRYPT_DOMAIN.
• Added use of panics where appropriate (kept return 1 so failures still exit functionality early).
• Improved inline docs.

Type of change

• Improvement (non-breaking change that does improve existing functionality)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• New and existing unit tests pass locally with my changes