! exec pint --no-color lint rules
! stdout .
cmp stderr stderr.txt

-- stderr.txt --
level=INFO msg="Finding all rules to check" paths=["rules"]
level=WARN msg="Failed to parse group entry" err="invalid group key alert" path=rules/strict.yml line=2
level=INFO msg="Checking Prometheus rules" entries=1 workers=10 online=true
Fatal: invalid group key alert (yaml/parse)
  ---> rules/strict.yml:2
 2 | - alert: Conntrack_Table_Almost_Full
     ^^^ invalid group key alert

level=INFO msg="Problems found" Fatal=1
level=ERROR msg="Execution completed with error(s)" err="found 1 problem(s) with severity Bug or higher"
-- rules/strict.yml --
groups:
- alert: Conntrack_Table_Almost_Full
  expr: ((node_nf_conntrack_entries / node_nf_conntrack_entries_limit) * 100) > 75
  for: 5m
  labels:
    component: conntrack
    priority: "3"
  annotations:
    summary: Conntrack table is at {{ $value|humanize }}%
