envoy-wasm

A foray into WASM filters for Envoy

Requirements

You need the following tools to play around with this project:

• Go - Go programming tools.
• TinyGo - Compiles Go to WASM (among other things).
• Docker - Container runtime (for running an Envoy image).
• bash - Needs no introduction.
• curl - Also, needs no introduction.

Usage

You can run the automated tests. This will:

• Build the WASM plugin
• Start Envoy in a Docker container configured with the WASM plugin
• Poke the WASM filter with a bunch of different inputs to test:
  • Normal operation
  • SQL injection detection
  • Rate limit enforcement

# Run the automated tests
./run-tests.sh

You can also just play around with this manually. Take a look through the run-tests.sh file for inspiration.

# Build the plugin
tinygo build -o overwatch.wasm -scheduler=none -target=wasi

# Launch Envoy.
docker run --rm --name envoy \
  -p 19000:19000 \
  -p 10000:10000 \
  -v $(pwd)/envoy-config.yaml:/etc/envoy/config.yaml \
  -v $(pwd)/overwatch.wasm:/etc/envoy/plugins/overwatch.wasm \
  envoyproxy/envoy:v1.24.0 -c /etc/envoy/config.yaml --component-log-level wasm:debug

# Send requests to the app through Envoy in a separate terminal
# If you send more than 5 requests in a 10 second window you will get rate limited.
curl localhost:10000 ...