Feature request: Finer grained control of matchers/mutations

[alexsnaps]

Looking into some requirements, I'd need to be able to remove headers starting with "some prefix". Currently the transformation::header::HeaderFilter wouldn't allow for that. It needs exact matching.

When you squint hard enough, removal of a header is done upon a condition matching on that header. So while it isn't related to my usecase per se, I do see a parallel with ConditionMatches and I, as a user would expect some common language amongst those. Thoughts?

So, instead to "just" opening a feature request for my own very selfish usecase, I wanted to open the discussion around scoping the problem first. I'm biased and would like to see some full expression language support as an ultimate option for these (e.g. CEL,... anyone? 👀 ). But whatever the solution(s) end up being, I'm mostly interested in the "broader picture", i.e. here do we want a common feel across (in this case) the HeaderFilter and ConditionMatch?

[araujof]

Hi @alexsnaps would the new strip assertion help with this? praxis-proxy/policy#56

Check the example (need to expand it).

[tkan145]

+1 to have full CEL support. Speaking of the "broader picture," do we plan to support CEL beyond header modification filters? I think it would be very useful to have CEL support in routing, logging filters, etc...

[shaneutt]

Our proposal process has been updated to no longer require discussions so we'll close this: Instead create a feature request on the repo in question and maintainers will assess 🖖