envoy_filter_metadata

Proxy-Wasm plugin example: Envoy metadata

Proxy-Wasm plugin that demonstrates reading metadata set by other Envoy filters.

Building

$ cargo build --target wasm32-wasip1 --release

Using in Envoy

This example can be run with docker compose and has a matching Envoy configuration.

$ docker compose up

Send a HTTP request to localhost:10000 that will return the configured response.

$ curl localhost:10000
Welcome, set the `x-custom-metadata` header to change the response!

Send a HTTP request to localhost:10000 with a x-custom-metadata header value to get the uppercased value in the response.

The response will also contain a response header uppercased-metadata: SOME-VALUE.

$ curl localhost:10000 -H "x-custom-metadata: some-value"
Custom response with Envoy metadata: "SOME-VALUE"