Final test: Observability: metrics, alerts, logs

Read the output

The /etc/prometheus/rules/disk.yml file with the rule is in place and passes promtool check rules. What makes Prometheus check it?

$ grep -A1 rule_files /etc/prometheus/prometheus.yml
rule_files:
  # - "first.rules"
$ curl -s localhost:9090/api/v1/rules | jq .data
{
  "groups": []
}

• A Restart node_exporter so it serves the metrics again.
• B Put the file or a directory pattern into rule_files and make Prometheus reread its configuration.
• C Rename the file to first.rules, as in the package example.
• D Wait: rules get picked up at the next scrape.