http-to-grpc-blog

Code for HTTP to GRPC blog

How to use

Run docker-compose up

Open your web browser to localhost:9090 to view the prometheus metrics. There will be a background app that will be sending traffic to the server and Prometheus will begin to populate the following metrics:

• wasmflow_requests_total
• wasmflow_requests_time_total
• wasmflow_requests_errors_total

Details

• server container is running a Wasmflow application. Wasmflow exposes a Stats method via GRPC.
• client container is continually calling the wasmflow application through envoy reverse proxy.
• envoy container is acting as a reverse proxy for the wasmflow application. It passes through the client calls directly without any modification. It. It is dynamically transforming the GRPC Stats response to application/json using GRPC to JSON transcoding. It is then converting from JSON to text/plain using Lua.
• prometheus container is scraping the /metrics endpoint that is sent to the wasmflow container's GRPC interface through envoy.