bytelyst-devops-tools/scripts/VMs/HostingerVM/CRON_SETUP.md

Hostinger VM — Cron Setup

Automated maintenance schedule for srv1491630. Scripts: vm-health-check.sh (read-only) + vm-cleanup.sh (safe cleanup).

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Quick install

SSH into the VM and run:

bash /opt/bytelyst/learning_ai_devops_tools/scripts/VMs/HostingerVM/vm-cleanup.sh --install-cron

This installs the full recommended schedule. To remove it:

bash /opt/bytelyst/learning_ai_devops_tools/scripts/VMs/HostingerVM/vm-cleanup.sh --uninstall-cron

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What gets scheduled

Schedule	Time (UTC)	Command	What it does
Daily	07:00	vm-health-check.sh	Read-only check; sends Telegram alert on WARNING/CRITICAL
Daily	03:00	vm-cleanup.sh	Prune Docker build cache only (always safe)
Weekly	Sun 02:00	vm-cleanup.sh	Standard cleanup (see below)
Monthly	1st 01:00	vm-cleanup.sh --full	Full cleanup (see below)

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What each mode does

Standard weekly cleanup (vm-cleanup.sh)

All steps are labelled SAFE — they only remove regenerable caches.

Step	What's removed	Risk
Docker build cache	Layer cache from docker build runs	Zero — rebuilds just take longer next time
Crash loop check	Detection only, no changes	Zero
Journal vacuum	Old journal entries beyond 200MB / 7 days	Zero — logs are already captured in syslog
APT cache	/var/cache/apt/archives/	Zero — packages can be re-downloaded
NPM cache	~/.npm/_cacache/	Zero — cache is re-populated on next npm install
.next/cache	Webpack/babel/TSC build cache dirs	Zero — rebuilt automatically on next next build

Monthly full cleanup (vm-cleanup.sh --full)

Adds these CAREFUL steps on top of the standard run:

Step	What's removed	Risk
Docker system prune	Stopped containers, unused networks, dangling images	Low — does NOT remove images used by any container
pnpm store prune	Packages not referenced by any node_modules	Low — only removes truly orphaned packages
Old log files	.gz log rotations older than 30 days	Low — old compressed logs
HOLD node_modules	node_modules in /opt/bytelyst/HOLD archived projects	Low — code intact, can reinstall with pnpm install

Never touched (by design)

• /opt/bytelyst/*/node_modules (active repos)
• /opt/bytelyst/*/src, /app, /backend, /web source code
• .next/standalone (production Next.js builds)
• Docker images used by currently configured containers
• /usr/local/lib/hermes-agent/
• /usr/share/ollama/ (models)
• /swapfile
• Any database volumes

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Manual crontab (if you prefer not to use --install-cron)

# Health check daily 07:00 UTC
0 7 * * * bash /opt/bytelyst/learning_ai_devops_tools/scripts/VMs/HostingerVM/vm-health-check.sh --quiet --notify 2>&1 | logger -t vm-health

# Build cache prune daily 03:00 UTC
0 3 * * * bash /opt/bytelyst/learning_ai_devops_tools/scripts/VMs/HostingerVM/vm-cleanup.sh --quiet 2>&1 | logger -t vm-cleanup

# Standard weekly cleanup Sunday 02:00 UTC
0 2 * * 0 bash /opt/bytelyst/learning_ai_devops_tools/scripts/VMs/HostingerVM/vm-cleanup.sh --quiet 2>&1 | logger -t vm-cleanup

# Full monthly cleanup 1st of month 01:00 UTC
0 1 1 * * bash /opt/bytelyst/learning_ai_devops_tools/scripts/VMs/HostingerVM/vm-cleanup.sh --full --quiet 2>&1 | logger -t vm-cleanup

Edit with: crontab -e

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Monitoring logs

# Tail cleanup log
tail -f /var/log/vm-cleanup.log

# Tail health check log
tail -f /var/log/vm-health-check.log

# See all cron output via syslog
grep vm-cleanup /var/log/syslog | tail -20
grep vm-health /var/log/syslog | tail -20

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Telegram alerts

The health check script sends a Telegram message when it detects WARNING or CRITICAL. It reads credentials from $HERMES_HOME/.env (usually /root/.hermes/.env).

Required keys in that file:

TELEGRAM_BOT_TOKEN=<your-bot-token>
TELEGRAM_CHAT_ID=<your-chat-id>

Both are already set if Hermes gateway is configured. Test with:

bash /opt/bytelyst/learning_ai_devops_tools/scripts/VMs/HostingerVM/vm-health-check.sh --notify

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Disk thresholds (from vm-health-check.sh)

Metric	WARNING	CRITICAL
Disk used %	> 55%	> 70%
Load average	> 4.0	> 8.0
RAM available	< 3 GB	< 1 GB
Swap used	> 1 GB	> 3 GB
Container restarts	> 10	> 50
Build cache	> 5 GB	> 20 GB

Thresholds are constants at the top of each script — easy to adjust.

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What the May 2026 incident would have caught

If this cron had been running during the May 26 incident:

• 07:00 daily health check → container_loops CRIT: admin-web(50x) → Telegram alert sent within hours of the loop starting
• 03:00 daily build cache prune → would have kept build cache under 5 GB instead of growing to 84 GB
• Monthly full cleanup → would have cleared the HOLD node_modules and old logs before they became a storage crisis