Envoy filter with Rust and WebAssembly

This is a demo accompanying a blogpost about building Envoy filters with Rust and WebAssembly.

Getting started

Install WebAssembly target for rust

$ rustup update
$ rustup target add wasm32-unknown-unknown

Install wasme

$ curl -sL https://run.solo.io/wasme/install | sh
$ export PATH=$HOME/.wasme/bin:$PATH

Clone the repo and use the makefile to build and run the demo:
```
$ make build-image
$ make deploy-envoy
```

Now you can open http://localhost:8080/headers. This is proxying to http://httpbin.org/headers, reflecting request headers back at you. You should see

"X-Hello": "Hello world from localhost:8080"

which was injected by the filter.