This is an example of application instrumented for Prometheus. By default it listens on port 8080 and exposes metrics on the /metrics endpoint.

The root endpoint will respond with a random delay (1 second at most).

Exposed metrics:

• orders_total, a fast moving counter.
• order_errors_total{stage=<stage>}, a slow moving counter.
• user_sessions, a gauge value randomly set between 0 and 100.

Usage

$ ./instrumented_app --help
usage: instrumented_app [<flags>]

Flags:
  --help                     Show context-sensitive help (also try --help-long and --help-man).
  --listen="127.0.0.1:8080"  Listen address
  --listen-metrics=""        Listen address for exposing metrics (default to 'listen' if blank)
  --basic-auth=""            Basic authentication (eg <user>:<password>)