cron-backup

Imported from Zewang0217/skill-construction (benign-500/cron-backup/SKILL.md). Install upstream with npx skills add Zewang0217/skill-construction --skill cron-backup. Copyright stays with the author.

Cron Backup

Automated backup scheduling with version detection and intelligent cleanup.

Quick Start

One-Time Backup

# Backup a directory with timestamp
./scripts/backup.sh /path/to/source /path/to/backup/dir

# Backup with custom name
./scripts/backup.sh /path/to/source /path/to/backup/dir my-backup

Schedule Daily Backup

# Set up daily backup at 2 AM
./scripts/setup-cron.sh daily /path/to/source /path/to/backup/dir "0 2 * * *"

Version-Aware Backup

# Backup only when version changes
./scripts/backup-versioned.sh /path/to/source /path/to/version/file /path/to/backup/dir

Cleanup Old Backups

# Keep only last 7 days of backups
./scripts/cleanup.sh /path/to/backup/dir 7

Core Capabilities

1. Directory Backup

• Creates timestamped tar.gz archives
• Preserves file permissions and structure
• Excludes common temp files (node_modules, .git, etc.)

2. Version-Triggered Backup

• Monitors version file or command output
• Backs up only when version changes
• Useful for software updates

3. Scheduled Execution

• Integrates with system cron
• Supports custom schedules
• Logs execution results

4. Automatic Cleanup

• Deletes backups older than N days
• Keeps minimum number of backups
• Prevents disk space exhaustion

Scripts

All scripts are in scripts/ directory:

• backup.sh - Single backup execution
• backup-versioned.sh - Version-triggered backup
• setup-cron.sh - Cron job setup
• cleanup.sh - Old backup cleanup
• list-backups.sh - List available backups

Backup Naming Convention

Backups follow the pattern: {name}_YYYYMMDD_HHMMSS.tar.gz

Examples:

• openclabak_20260204_101500.tar.gz
• myapp_20260204_000000.tar.gz

Workflow

Setting Up Automated Backups

1. Decide backup strategy

   • What to backup (source directory)
   • Where to store (backup directory)
   • How often (schedule)
   • Retention policy (cleanup days)

2. Run initial backup

   ./scripts/backup.sh /source /backup

3. Set up schedule

   ./scripts/setup-cron.sh daily /source /backup "0 2 * * *"

4. Configure cleanup

   ./scripts/setup-cron.sh cleanup /backup "" "0 3 * * *" 7

Version-Aware Backup Workflow

For software that changes version (like OpenClaw):

1. Identify version source

   • Command: openclaw --version
   • File: /path/to/version.txt

2. Set up versioned backup

   ./scripts/backup-versioned.sh /app /app/version.txt /backups/app

3. Schedule version check

   ./scripts/setup-cron.sh versioned /app /backups/app "0 */6 * * *"

Common Patterns

Pattern 1: Daily User Data Backup

# Backup workspace daily, keep 30 days
./scripts/setup-cron.sh daily /home/user/workspace /backups/workspace "0 2 * * *"
./scripts/setup-cron.sh cleanup /backups/workspace "" "0 3 * * *" 30

Pattern 2: Version-Aware Application Backup

# Backup when application updates
./scripts/setup-cron.sh versioned /opt/myapp /backups/myapp "0 */6 * * *"
./scripts/setup-cron.sh cleanup /backups/myapp "" "0 4 * * 0" 10

Pattern 3: Multi-Directory Backup

# Backup multiple directories
./scripts/backup.sh /home/user/.config /backups/config
./scripts/backup.sh /home/user/projects /backups/projects

Cron Schedule Format

Standard cron format: minute hour day month weekday

Common schedules:

• Daily at 2 AM: 0 2 * * *
• Every 6 hours: 0 */6 * * *
• Weekly on Sunday: 0 0 * * 0
• Every 30 minutes: */30 * * * *

Cleanup Policies

• Time-based: Keep backups for N days
• Count-based: Keep last N backups
• Combined: Default keeps 7 days minimum, but at least 3 backups

Troubleshooting

• Permission denied: Ensure scripts are executable (chmod +x scripts/*.sh)
• Cron not running: Check cron service status (systemctl status cron)
• Disk full: Run cleanup manually or reduce retention period
• Backup fails: Check source directory exists and is readable