ORT: Delete untracked files due to removed header rewrite or delivery delivery services

[smalenfant]

I'm submitting a enhancement request

Today, removed header rewrite from TO or deleted delivery services keeps the files on disk. I would call this garbage collection that needs cleaned up.

This might apply more than just header rewrite.

Traffic Control components affected ...

• Traffic Ops ORT

Current behavior:

header rewrite are kept when header rewrite parameter are removed and when delivery services are deleted.

New behavior:

Delete untracked files due to the above

Minimal reproduction of the problem with instructions:

• Add header rewrite to a DS
• Run ORT and verify the changes
• Remove header from the DS
• Run ORT and observer files are kept on disk
• Delete delivery service
• Run ORT and observer files are kept on disk

[rob05c]

More than just garbage, this can potentially cause bugs. E.g. if a Header Rewrite is completely removed from a DS, it can end up sticking around because ORT no longer knows the file exists