Envoy complains about request_trailer_mode not being set to SEND with 1.4.1

[sanjaypujare]

Description: I installed the latest 1.4.1 of Envoy Gateway and tried to use the new FullDuplex body mode in one of my EnvoyExtensionPolicies. However Envoy complains about "request_trailer_mode not being set to SEND"

Repro steps: I added an extension as follows:

apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyExtensionPolicy
metadata:
  name: my-ext-proc
spec:
  targetRefs:
    - group: gateway.networking.k8s.io
      kind: Gateway
      name: eg
  extProc:
    - backendRefs:
        - name: my-ext-proc-ingress
          port: 443
      processingMode:
        request:
          body: FullDuplexStreamed
        response: 
          body: FullDuplexStreamed

However when I triggered this extension by sending a request, Envoy generates an error as follows:

severity: "ERROR"

[source/extensions/config_subscription/grpc/grpc_subscription_impl.cc:138] gRPC config for type.googleapis.com/envoy.config.listener.v3.Listener rejected: Error adding/updating listener(s) default/eg/http: If the ext_proc filter has the request_body_mode set to FULL_DUPLEX_STREAMED, then the request_trailer_mode has to be set to SEND

I notice there's no way to add "trailers" in the extension. How can we use FullDuplexStreamed body mode? How was it verified in the tests?

Environment: gateway version, envoy version: 1.4.1

Logs:

[arkodg]

cc @guydc

[sanjaypujare]

cc @guydc

Thanks!

Another ping.

[arkodg]

@kfswain was this tested ?

marking it as help-wanted

[arkodg]

can this be worked around with allowModeOverride ?

[arkodg]

ignore my prev comment, this is a config validation issue https://github.com/envoyproxy/envoy/blob/9739df72fc281dadfd52a542e2ffdc5f8074122c/source/extensions/filters/http/ext_proc/config.cc#L50

looks like this feature was not tested, the decision needed here is, to expose request_trailer_mode in the API or set it to SEND by default for this case

[sanjaypujare]

ignore my prev comment, this is a config validation issue https://github.com/envoyproxy/envoy/blob/9739df72fc281dadfd52a542e2ffdc5f8074122c/source/extensions/filters/http/ext_proc/config.cc#L50

looks like this feature was not tested, the decision needed here is, to expose request_trailer_mode in the API or set it to SEND by default for this case

My preference is to "expose request_trailer_mode in the API". But if that needs more work/time then a quick fix could be to use SEND for trailers until a proper fix is implemented

[guydc]

Agree with the quick fix for now, if we have use for trailers later on, we can expand the API.

[sanjaypujare]

Agree with the quick fix for now, if we have use for trailers later on, we can expand the API.

Trailers will be needed for grpc or other http2 use-cases. What's the ETA for the quick fix if one is planned?

[guydc]

will try working to open a fix PR this week. No ETA for the next patch release at the moment.

[sanjaypujare]

arkodg closed this as completedin #632351 minutes ago

Great! Will this be in 1.4.2? Any idea of the ETA for 1.4.2?