feat(middleware): extend deny middleware to deny based on prefix or suffix

[Litarnus]

Extends the deny-tag middleware to allow denying based on prefix or suffix.

This PR extends the deny-tag middleware that enables filtering of metric tag values by prefix and/or suffix. The primary use case is to reduce metric cardinality by automatically stripping common prefixes/suffixes from tag values in a centralized way.

The main benefits are:

• A central place to filter out tags vs filter it out on the caller side
• Reduces the risk of accidentally introducing a high cardinality tag
• Opt in/out at a central place
• No need to maintain a allow/deny list, tags can be added using a configured format and will automatically be stripped

[untitaker]

can this be folded into deny-tag middleware? if not, i'd avoid introducing another verb "strip" and replace it with "deny" (deny-tag-substring or similar

[Litarnus]

can this be folded into deny-tag middleware? if not, i'd avoid introducing another verb "strip" and replace it with "deny" (deny-tag-substring or similar

Yes I think that should be possible. I will have a look.

[Litarnus]

I'm thinking about calling this prefix/suffix, what do you think?

[untitaker]

no strong opinion, either is fine. i think the "best" API would be to impl glob support in deny-tag, but probably too complicated and possibly slow.

[untitaker]

no strong opinion, either is fine. i think the "best" API would be to impl glob support in deny-tag, but probably too complicated and possibly slow.