add waypoint context to envoyfilter

[dprotaso]

Part of istio/istio#43720

/assign @howardjohn

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[howardjohn]

If we are to implement EnvoyFilter on waypoint I definitely think this is a step in the right direction. However, I don't think we yet have consensus that it is something that is desired at all. We probably would need to settle that before moving forward

[keithmattix]

I added my thoughts here: istio/istio#55149 (comment)

[linsun]

We discussed this in a meeting recently, and we couldn't reach consensus that we need to implement envoy filter support in waypoint.

[zirain]

IMO, you cannot add every features envoy supported into first class API.

For RateLimit, ExtProc, we can support it by first class API. How to tweak some configuration in Cluster/Route/Listerner?

If you search the github issue, lot of edge cases were fixed by EnvoyFilter, I don't think it won't happen in Waypoint.

In the end, every vendor need to add EF support in their forks, that's the worst to the community.

[vikaschoudhary16]

Yeah, I noticed istio/istio#55149 (comment) and we also need EF patching at waypoint. There could be many users affected. so +1 to @zirain.

[zhaohuabing]

+1

I’d really love to see this PR land—EF support for Waypoint is an important step forward. It helps ensure a smooth migration path for existing sidecar users and builds confidence for those looking to adopt Ambient.

Regarding the concern around unstable xDS and patch compatibility across Istio versions: I believe all EF users understand that patches can break and would take the necessary steps to validate them before upgrading. Giving users the option to move forward—while being aware of the risks—feels more empowering than blocking EF entirely due to potential issues.

[hzxuzhonghu]

Personally i'd like to see same features applied to ambient as envoyfilter, it will benefit the community a lot.

So LGTM

[vikaschoudhary16]

@ramaraochavali wdyt?

[ramaraochavali]

@linsun what are the specific concerns discussed in WG meeting for enabling Envoy filters for waypoints?