2026 Rent Mac Mini 7×24 Decision Matrix: certbot Auto-Renewal, launchd Health Probes & Night Silent Window Parameters
Indie developers who rent a Mac Mini for seven by twenty four gateways, reverse proxies, and uptime monitors still lose HTTPS when certbot renewal drifts off calendar—or reloads the wrong process at two a.m.
This guide freezes a decision matrix for challenge mode, launchd timers, health probes, and UTC silent windows on Apple Silicon rentals. You get executable plist and crontab snippets, six rollout steps, citeable thresholds, and links to Home, launchd vs PM2, and our APFS disk waterline FAQ.
Why TLS renewal breaks seven by twenty four Mac Mini rentals
- Challenge drift. HTTP-01 fails when port eighty closes; DNS-01 tokens expire when API keys live only in shell history.
- Reload blast radius. A naive
renew-hookrestarts every service—including an OpenClaw gateway—instead of nginx only. - Silent blind spots. Probes watch process uptime, not
notAfter, so TLS expires while monitors stay green.
HTTP-01 vs DNS-01: which certbot challenge fits your rental?
Pick one primary mode per hostname. Wildcards require DNS-01; single-host reverse proxies on a rented Mac Mini often stay on HTTP-01 when ports eighty and four forty-three reach the internet.
- HTTP-01: nginx serves
/.well-known/acme-challenge/when port eighty reaches the rental. - DNS-01: plugin auth for wildcards or blocked port eighty—store API tokens in Keychain.
certbot certonly --staging --nginx -d gateway.example.dev
# production after dry-run:
certbot certonly --nginx -d gateway.example.dev --deploy-hook /usr/local/bin/reload-proxy.sh7×24 certbot and launchd decision matrix
Freeze these parameters in git. They survive consumer uplinks and single-volume 7×24 hosting on M4 rentals.
| Control | Starter value | Notes |
|---|---|---|
| Challenge mode | HTTP-01 or DNS-01 (one primary) | Wildcards force DNS-01; document open ports in runbook. |
| Renew cadence | 03:17 and 15:17 local daily | Stagger from backup and batch windows. |
| Health probe interval | 60s curl + 7d expiry gate | Page when cert expires in < 14 days outside silence. |
| UTC silent band | 22:00–06:00 + 30 min buffer | Suppress renew-noise webhooks; P1 bypasses silence. |
| Scheduler | launchd LaunchAgent | crontab acceptable for labs; see snippet below. |
| renew-hook scope | Proxy reload only | Never restart OpenClaw gateway on cert swap. |
launchd timers, renew-hook, and crontab fallback
Prefer launchd StartCalendarInterval on rentals: logs land in predictable paths and jobs reload after reboot. Pair with a renew-hook that validates nginx config before reload.
# ~/Library/LaunchAgents/com.runmini.certbot-renew.plist (excerpt)
ProgramArguments: certbot renew --quiet --deploy-hook /usr/local/bin/reload-proxy.sh
StartCalendarInterval: 03:17 and 15:17 daily
StandardOutPath: /var/log/certbot-renew.log
# renew-hook — proxy only; do not restart OpenClaw gateway
nginx -t && kill -HUP "$(cat /usr/local/var/run/nginx.pid)"
# crontab lab fallback:
# 17 3,15 * * * certbot renew -q --deploy-hook /usr/local/bin/reload-proxy.sh
Bootstrap with launchctl bootstrap gui/$(id -u) …/com.runmini.certbot-renew.plist. See launchd vs PM2 when Node gateways share the host.
Silent window, health probes, and alert routing
Schedule certbot renewal inside a UTC silent window so expected reload noise does not page on-call. Run a separate health check job every sixty seconds that fails only on real TLS or upstream errors.
# tls-health.sh — 60s LaunchAgent
DAYS=$(( ($(date -j -f "%b %d %T %Y %Z" "$(openssl … -enddate|cut -d= -f2)" +%s) - $(date +%s)) / 86400 ))
[ "$DAYS" -lt 14 ] && curl -fsS -X POST "$ALERT_URL" -d "{\"days_left\":$DAYS}"
curl -fsS --max-time 5 https://gateway.example.dev/healthz- Suppress non-P1 webhooks 22:00–06:00 UTC plus thirty-minute renew buffer.
- Page immediately when
days_left < 7; warn only above fourteen days.
Disk and log waterlines on APFS rentals
Align with our APFS waterline FAQ before unattended renew.
- Yellow fifteen percent APFS free—pause renew; red ten percent—stop certbot and page.
- Cap
certbot-renew.logat 128 MB via newsyslog.
Six rollout steps for seven by twenty four TLS on a rental
- Provision. Purchase, SSH via Help, baseline
df -hfrom Home. - Staging certs.
certbot certonly --stagingwith chosen challenge. - launchd agent. Load renew plist and
reload-proxy.sh; tailcertbot-renew.log. - Health probe. Sixty-second TLS plus
/healthz; page outside silent band. - Production. Re-run without staging; log
notAfter. - Fire drill.
certbot renew --dry-run; confirm proxy-only reload and muted UTC alerts.
Cite: renew at 03:17 and 15:17 local; health probe 60s; TLS page threshold 14 days left, immediate at 7 days; silence 22:00–06:00 UTC plus 30 minute buffer; APFS yellow 15% red 10%; certbot log cap 128 MB × 7 rotations; renew-hook reloads nginx only.
Power-loss recovery FAQ
Will certbot renew break my OpenClaw gateway during night batches?
No—if renew-hook reloads nginx or Caddy only. Keep OpenClaw on loopback; never restart the gateway label when certificates rotate. Run renew inside the UTC silent window and test with certbot renew --dry-run first.
launchd or crontab for certbot on macOS?
Use launchd LaunchAgents on 7×24 hosting rentals—they survive reboot and log to fixed paths. crontab is fine for local labs; mirror the same --deploy-hook script either way.
After a power blip, what should I verify first?
Check launchctl print gui/$(id -u)/com.runmini.certbot-renew, run certbot certificates, confirm APFS free above yellow gate per the APFS FAQ, then re-enable outbound alerts.
Rent a Mac Mini for 7×24 TLS and health probes
RunMini Apple Silicon nodes stay online for gateways, proxies, and monitors that need unattended certbot renewal. Compare Plans, open Purchase without login, and read SSH / VNC Help after checkout.
Summary. Freeze challenge mode, launchd renew timers, renew-hook proxy reloads, sixty-second health checks, and UTC silent windows before you rent a Mac Mini for seven by twenty four TLS. Return to Home after your first dry-run renew completes without paging on-call.