vms: add monitoring stack and node-exporter for docker host
utility-101-shadow:
- Add full monitoring stack (Prometheus + Blackbox Exporter + Alertmanager)
with Docker Compose and a systemd unit (monitoring.service)
- Prometheus scrapes: itself, blackbox-exporter, and node-exporter on
the docker host (docker:9100); blackbox probes cover HTTPS endpoints
with TLS cert monitoring
- Alertmanager routes warnings to Slack/Discord, critical alerts also
to email (Gmail SMTP); inhibit rule suppresses SSLCertExpiringSoon
when SSLCertExpired already fires
- Alert rules: 11 node-exporter alerts (host down, CPU, memory, disk
fill/prediction, iowait, OOM kill, systemd failed units) + 3 blackbox
alerts (probe failed, SSL expiring, SSL expired)
- readme: add services list and Docker Engine installation steps
docker host:
- Add node-exporter container running with host pid/network and
read-only mounts of /proc, /sys, / for full host metrics visibility
- Enable --collector.systemd for systemd unit state metrics
- Add systemd unit (node-exporter.service) to manage the container
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>