Hello! I need some help with Wiremock gRPC plugin. After configuring it with mapping like that

{
  "request": {
    "method": "POST",
    "urlPath": "/dbag.energy.m7g.internal.core.v1.DataAccessService/WatchOutputEvents"
  },
  "response": {
    "status": 200,
    "headers": {
      "Content-Type": "application/grpc+json"
    },
    "jsonBody": {
      "snapshot": {
        "orders": {
          "order": [
            {
              "id": "1"
            },
            {
              "id": "2"
            },
            {
              "id": "3"
            }
          ]
        },
        "product_snapshot": {
          "product": []
        }
      }
    }
  }
}

I'm getting errors at the client side like that

Exception in thread "main" io.grpc.StatusException: INTERNAL: gRPC frame header malformed: reserved bits not zero

I've tried different client configurations with palintext parameter and without it but result is generally the same. Could you hel;p me to guess what could be wrong there...

Bit of a punt, but have you tried removing the Content-Type header?

Yes. I'm getting error that content type null is wrong.

Did you remove the

headers

element completely or null the value?

I remove it completely like it was in the example

I think I’d need a reproducer project to make any more progress with this. I can’t see anything obviously wrong with what you’re attempting.

Hm... I will try... But may I ask a bit different thing. As far as I know gRPC is a binary format and as I can see from Wireshark logs all my gRPC servers are sending binary code which is not looks like JSON. But as far as I can see the Wiremock in gRPC mode is operating with JSON. Where I'm wrong here?

The WireMock extension converts the JSON response you specify in the stub to protobuf

Looks like I found a way to reproduce! If in examples from here https://github.com/wiremock/wiremock-grpc-demos/tree/main You will change gRPC server implementation to

testImplementation("io.grpc:grpc-netty:1.61.1")

You will get same error as me. UPDATE: It's about the gRPC version. If I downgrade to 1.59.0 it works also with Netty implementation. If you don't mind I can try to fix that.

That would be much appreciated!

Sorry that was my fault. I used wiremock-grp-extension instead of wiremock-grap-extension-standalone

Ah, that’ll be it then 🙂