Proxy Wasm Hello World

Proxy-Wasm enables developers to write Wasm proxy filters in their preferred language and deploy them to various dataplanes.

Benefits

• Wasm enables powerful and performant extensibility of your datapath.
• Sharing a common extension ecosystem across proxy implementations strengthens community growth.

What is WebAssembly?

First designed as an enhancement for modern web browsers, WebAssembly (Wasm) joined HTML, CSS, and JavaScript to be announced as the fourth W3C recommended "language for the Web". Wasm enabled Ahead of Time compiled (AOT) binaries to run in the browser unlocking new capabilities in the client rendered internet.

The Wasm System Interface (WASI) project extended Wasm beyond the browser by establishing the needed Application Binary Interface (ABI) standardization effort to formally build ecosystems of server side Wasm applications.

What is WebAssembly for Proxies?

Wasm based proxy filter extensions depend on a proxy exposing an embedded Wasm runtime interface. First featured in the Envoy Proxy, Wasm for Proxies defines a standard integration spec to facilitate communication between the proxy host program and data filter extensions over the WASI ABI.

Get Started:

Dependencies:

• git
• httpie
• docker

1. Make sure you have all dependencies

   Click to expand dependency check command

   bash -c "cat <<EOF | bash -es --
   git --version
   httpie --version
   docker --version
   EOF"

2. Clone Wasm Filter repo for: proxy_wasm_hello_world

   git clone https://github.com/kong/proxy-wasm-hello-world wasm

3. Run Kong API Gateway:

   curl -Ls https://get.konghq.com/quickstart | bash -s -- -i incubator -t gateway-wasmer-3.0.0.0 \
     -e "KONG_WASM=on" -e "KONG_WASM_MODULES=/wasm/proxy_wasm_hello_world.wasm" -v $(pwd)/wasm:/wasm

4. Create a Mockbin.com demo Service:

   http POST :8001/services/ name="mockbin" host="mockbin.com" path="/bin/ccb2968e-08e8-43af-babd-878c9f269486" protocol="http"

5. Create a Mockbin.com demo Route:

   http POST :8001/services/mockbin/routes name="mockbin" "paths[]=/mockbin"

6. Configure Proxy Wasm filter proxy_wasm_hello_world on the mockbin route:

   http POST :8001/services/mockbin/plugins name="proxy-wasm" "config[filters][0][name]=proxy_wasm_hello_world"

7. Check for header: Cowsay: Hello World

   http GET :8000/mockbin

   • Result:

   ❯ http GET :8000/mockbin
   HTTP/1.1 200 OK
   Connection: keep-alive
   Content-Length: 15
   Cowsay: Hello World
   Date: Wed, 21 Sep 2022 22:46:01 GMT
   Powered-By: proxy-wasm
   Server: nginx
   Via: kong/3.0.0.0-enterprise-edition
   X-Kong-Proxy-Latency: 340
   X-Kong-Upstream-Latency: 0
   
   Hello, World!