Files
nixos/manifests/monitoring/alerts.yaml
T
root 7fee882488
buildbot/nix-eval Build done.
fix: security and monitoring improvements
Issue 1 - Grafana secret key:
- Replace hardcoded '123456789' secret_key in hosea Grafana config
  with an agenix-managed secret ($__file interpolation)
- Add age.secrets.grafana-secret-key declaration to hosea config
- Register grafana-secret-key.age in secrets/secrets.nix (publicKeys=everyone)
- NOTE: The .age file still needs to be created by running:
    agenix -e secrets/grafana-secret-key.age
  and entering a strong random secret (e.g. from 'pwgen -s 64 1')

Issue 2 - Prometheus stale targets:
- Remove retired vm-gitlab host from all three scrape jobs
  (node, systemd, ping) in manifests/monitoring/config.yaml
- linode was already present in all scrape jobs

Issue 3 - Prometheus alerting gaps:
- Wire up rule_files in prometheus.yml pointing at alerts.yml
- Add manifests/monitoring/alerts.yaml with alerting rules:
    * HostDown (node unreachable > 2m) - critical
    * HighCPULoad (>90% for 10m) - warning
    * LowDiskSpace (<10% free) - warning
    * CriticalDiskSpace (<5% free) - critical
    * HighMemoryUsage (>90% for 10m) - warning
    * ResticBackupStaleness (no success > 26h) - warning
    * PodCrashLooping - warning
    * PodNotReady (>10m) - warning
- Mount alerts ConfigMap as separate volume subPath in deployment
  so prometheus.yml and alerts.yml are both accessible at
  /etc/prometheus/ without conflicts
2026-03-25 06:02:17 -05:00

87 lines
3.9 KiB
YAML

apiVersion: v1
kind: ConfigMap
metadata:
name: prometheus-alerts
data:
alerts.yml: |
groups:
- name: host_health
rules:
- alert: HostDown
expr: up{job="node"} == 0
for: 2m
labels:
severity: critical
annotations:
summary: "Host {{ $labels.instance }} is unreachable"
description: "Node exporter on {{ $labels.instance }} has been unreachable for more than 2 minutes."
- alert: HighCPULoad
expr: 100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100) > 90
for: 10m
labels:
severity: warning
annotations:
summary: "High CPU on {{ $labels.instance }}"
description: "CPU usage on {{ $labels.instance }} has been above 90% for 10 minutes (current: {{ $value | printf \"%.1f\" }}%)."
- alert: LowDiskSpace
expr: (node_filesystem_avail_bytes{mountpoint="/",fstype!~"tmpfs|overlay"} / node_filesystem_size_bytes{mountpoint="/",fstype!~"tmpfs|overlay"}) * 100 < 10
for: 5m
labels:
severity: warning
annotations:
summary: "Low disk space on {{ $labels.instance }}"
description: "Filesystem {{ $labels.mountpoint }} on {{ $labels.instance }} has less than 10% free ({{ $value | printf \"%.1f\" }}% remaining)."
- alert: CriticalDiskSpace
expr: (node_filesystem_avail_bytes{mountpoint="/",fstype!~"tmpfs|overlay"} / node_filesystem_size_bytes{mountpoint="/",fstype!~"tmpfs|overlay"}) * 100 < 5
for: 2m
labels:
severity: critical
annotations:
summary: "Critical disk space on {{ $labels.instance }}"
description: "Filesystem {{ $labels.mountpoint }} on {{ $labels.instance }} has less than 5% free ({{ $value | printf \"%.1f\" }}% remaining)."
- alert: HighMemoryUsage
expr: (1 - (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes)) * 100 > 90
for: 10m
labels:
severity: warning
annotations:
summary: "High memory usage on {{ $labels.instance }}"
description: "Memory usage on {{ $labels.instance }} is above 90% for 10 minutes (current: {{ $value | printf \"%.1f\" }}%)."
- name: backup_health
rules:
- alert: ResticBackupStaleness
# restic_last_run_success{repository=...} is exported by the prometheus graphite bridge from nas1
# Alert if any backup job hasn't succeeded in the last 26 hours
expr: time() - restic_last_success_timestamp_seconds > 93600
for: 0m
labels:
severity: warning
annotations:
summary: "Backup stale for {{ $labels.repository }}"
description: "Restic backup job '{{ $labels.repository }}' has not succeeded in over 26 hours."
- name: kubernetes
rules:
- alert: PodCrashLooping
expr: rate(kube_pod_container_status_restarts_total[15m]) * 60 * 15 > 0
for: 5m
labels:
severity: warning
annotations:
summary: "Pod {{ $labels.namespace }}/{{ $labels.pod }} is crash-looping"
description: "Pod {{ $labels.pod }} in namespace {{ $labels.namespace }} has restarted {{ $value | printf \"%.0f\" }} times in the last 15 minutes."
- alert: PodNotReady
expr: kube_pod_status_ready{condition="true"} == 0
for: 10m
labels:
severity: warning
annotations:
summary: "Pod {{ $labels.namespace }}/{{ $labels.pod }} not ready"
description: "Pod {{ $labels.pod }} in namespace {{ $labels.namespace }} has not been ready for more than 10 minutes."