This example app serves as an example of how one can easily instrument HTTP handlers with Prometheus metrics.
Usage is simple, on any request to /sayhello/{name} the request will result in a 200 response code. This increments the counter for this response code. A request to any other endpoint will result in a 404 response code, therefore increments that respective counter. A POST request will result in a 500 error code.
In the endpoint /metrics the app will expose different prometheus metrics, being greeting_seconds_* the metrics generated to expose HTTP requests information.
PromQL requests for the golden signals:
- Requests per second sum(rate(greeting_seconds_count{}[2m])) //Including errors rate(greeting_seconds_count{code="200"}[2m]) //Only 200 OK requests
- Average request time sum(greeting_seconds_sum)/sum(greeting_seconds_count)
- Errors per second sum(rate(greeting_seconds_count{code!="200"}[2m]))
- Saturation to be generated upon system metrics (cpu,)
A Docker image is available at:
sysdiglabs/prom-example:latest