Hands-On Software Engineering with Golang

Using Prometheus as a source for alert events

In order to use Prometheus as an alert-generating source, operators must define a collection of alert rules that Prometheus should monitor. The alert rule definitions live in external YAML files that are imported by the main Prometheus configuration file using a rule_files block, as follows:

# prometheus.yml

global:
  scrape_interval:     15s

rule_files:
  - 'alerts/*.yml'

Prometheus organizes multiple alert rules into groups. Rules within a group are always evaluated sequentially while each group is evaluated in parallel.

Let's take a look at the structure of a simple alert definition. The following snippet defines an alert group with the name example that contains a single alert definition:

groups: ...