Git Repository Backup System (systemd)

A simple, configurable backup solution for git repositories using rsync with automatic rotation, managed by systemd with journald logging.

Features

✓ Incremental backups using rsync
✓ Timestamped backup directories
✓ Automatic rotation (keeps N most recent backups)
✓ Automatic compression of old backups (keep recent ones uncompressed for fast restoration)
✓ Configuration file for all settings
✓ systemd service and timer for reliable scheduling
✓ Centralized logging via journald
✓ Easy monitoring with systemctl and journalctl

Installation

Quick Install

sudo ./install.sh

Manual Install

# build script (requires go)
make
# Copy script to system
sudo cp ./bin/git-backup /usr/local/bin/git-backup
sudo chmod +x /usr/local/bin/git-backup

# Create config directory
sudo mkdir -p /etc/git-backup
sudo cp backup-config.conf /etc/git-backup/

# Install systemd units
sudo cp git-backup.service /etc/systemd/system/
sudo cp git-backup.timer /etc/systemd/system/
sudo systemctl daemon-reload

Configuration

Edit /etc/git-backup/backup-config.conf:

# Source directory containing git repositories
SOURCE_PATH="/srv/git/repos"

# Destination directory for backups
BACKUP_PATH="/mnt/backups/git"

# Number of backup copies to keep
KEEP_COPIES=7

# Number of recent backups to keep uncompressed (for fast restoration)
# Older backups will be compressed to .tar.gz to save space
# Set to 0 to disable compression
KEEP_UNCOMPRESSED=2

# Backup interval (documentation only, actual schedule via timer)
BACKUP_INTERVAL_HOURS=24

Configuration Options

Option	Description	Example
`SOURCE_PATH`	Directory containing git repositories to backup	`/srv/git`
`BACKUP_PATH`	Where backup directories will be created	`/mnt/backups/git`
`KEEP_COPIES`	Number of recent backups to keep (older ones deleted)	`7` (keep 1 week)
`KEEP_UNCOMPRESSED`	Number of recent backups to keep uncompressed (older ones compressed to .tar.gz)	`2` (keep 2 newest uncompressed)
`BACKUP_INTERVAL_HOURS`	Documentation of intended schedule	`24` (daily)

Usage

Enable Automatic Backups

# Enable and start the timer
sudo systemctl enable --now git-backup.timer

# Check timer status
sudo systemctl list-timers git-backup.timer

Manual Backup

# Run backup immediately
sudo systemctl start git-backup.service

# Check if it's running
sudo systemctl status git-backup.service

View Logs

# Follow live logs
sudo journalctl -u git-backup.service -f

# View last 50 lines
sudo journalctl -u git-backup.service -n 50

# View logs from today
sudo journalctl -u git-backup.service --since today

# View logs from specific date
sudo journalctl -u git-backup.service --since "2024-12-01" --until "2024-12-18"

# Show only errors
sudo journalctl -u git-backup.service -p err

Check Backup Status

# Check service status
sudo systemctl status git-backup.service

# Check timer status (when next backup will run)
sudo systemctl list-timers git-backup.timer

# Check if timer is enabled
sudo systemctl is-enabled git-backup.timer

Customizing the Schedule

Edit /etc/systemd/system/git-backup.timer:

Default (Daily at Midnight)

[Timer]
OnCalendar=daily
Persistent=true
RandomizedDelaySec=30min

Every 6 Hours

[Timer]
OnCalendar=*-*-* 00,06,12,18:00:00
Persistent=true
RandomizedDelaySec=30min

Twice Daily (2 AM and 2 PM)

[Timer]
OnCalendar=*-*-* 02,14:00:00
Persistent=true
RandomizedDelaySec=30min

Weekly (Sunday at 3:00 AM)

[Timer]
OnCalendar=Sun *-*-* 03:00:00
Persistent=true
RandomizedDelaySec=30min

Specific Days (Monday, Wednesday, Friday at 1 AM)

[Timer]
OnCalendar=Mon,Wed,Fri *-*-* 01:00:00
Persistent=true
RandomizedDelaySec=30min

After editing the timer:

sudo systemctl daemon-reload
sudo systemctl restart git-backup.timer

Backup Structure

Backups are stored with timestamps. Recent backups remain as directories, older ones are compressed:

/mnt/backups/git/
├── backup_20241218_020000/          (newest - uncompressed directory)
├── backup_20241217_020000/          (recent - uncompressed directory)
├── backup_20241216_020000.tar.gz    (older - compressed)
├── backup_20241215_020000.tar.gz    (older - compressed)
└── ...

How Rotation Works

Script creates new backup with timestamp: backup_YYYYMMDD_HHMMSS
After backup completes, script counts existing backups
If count > KEEP_COPIES, oldest backups are deleted
Only the N most recent backups are kept

Example with KEEP_COPIES=3:

Before: 3 backups exist
Run backup → creates 4th backup
Rotation → deletes oldest, keeps 3 newest

How Compression Works

Old backups are automatically compressed to save disk space while keeping recent backups as directories for fast restoration.

Process:

After successful backup and before rotation
Script identifies backups older than the N most recent (where N = KEEP_UNCOMPRESSED)
Compresses them to .tar.gz using gzip
Removes original directory after successful compression
Rotation then considers both compressed and uncompressed backups

Example with KEEP_UNCOMPRESSED=2, KEEP_COPIES=7:

Latest 2 backups: uncompressed directories (fast access)
Next 5 oldest: compressed .tar.gz files (space efficient)
Anything older: deleted

Disable compression: Set KEEP_UNCOMPRESSED=0 in config file

Monitoring

Check Recent Backups

ls -lh /mnt/backups/git/

View Last Backup Run

sudo journalctl -u git-backup.service -n 100 --no-pager

Check Backup Size

du -sh /mnt/backups/git/backup_*

List All Backups

find /mnt/backups/git -maxdepth 1 -type d -name "backup_*" | sort

Service Management Commands

# Start backup immediately
sudo systemctl start git-backup.service

# Stop a running backup
sudo systemctl stop git-backup.service

# Restart the timer
sudo systemctl restart git-backup.timer

# Disable automatic backups (but don't stop current)
sudo systemctl disable git-backup.timer

# Enable automatic backups
sudo systemctl enable git-backup.timer

# Check service status
sudo systemctl status git-backup.service

# Check timer status
sudo systemctl status git-backup.timer

Restoring from Backup

Restore from Uncompressed Backup

# Restore specific repository
rsync -av /mnt/backups/git/backup_20241218_020000/myrepo.git/ /srv/git/myrepo.git/

# Restore all repositories
rsync -av /mnt/backups/git/backup_20241218_020000/ /srv/git/

Restore from Compressed Backup

# Extract first, then restore
cd /mnt/backups/git
tar -xzf backup_20241218_020000.tar.gz
rsync -av backup_20241218_020000/ /srv/git/

# Or extract and restore specific repository
tar -xzf /mnt/backups/git/backup_20241218_020000.tar.gz -C /tmp
rsync -av /tmp/backup_20241218_020000/myrepo.git/ /srv/git/myrepo.git/
rm -rf /tmp/backup_20241218_020000

Troubleshooting

Check Service Logs for Errors

sudo journalctl -u git-backup.service -p err --since today

Test Backup Manually

# Run directly (not via systemd)
sudo /usr/local/bin/git-backup

Permission Issues

# Ensure backup script can read source
sudo chmod +r /path/to/repos

# Ensure backup destination is writable
sudo chown root:root /mnt/backups/git

Timer Not Running

# Check if timer is active
sudo systemctl is-active git-backup.timer

# Check if timer is enabled
sudo systemctl is-enabled git-backup.timer

# Enable and start if needed
sudo systemctl enable --now git-backup.timer

Disk Space

# Check available space
df -h /mnt/backups/git

# See backup sizes
du -sh /mnt/backups/git/backup_*

# Consider reducing KEEP_COPIES if space is tight

View Systemd Timer Details

# List all timers
sudo systemctl list-timers --all

# Show timer details
sudo systemctl show git-backup.timer

Verify Backup Integrity

# Compare file counts
find /srv/git -type f | wc -l
find /mnt/backups/git/backup_20241218_020000 -type f | wc -l

# Check specific git repository
cd /mnt/backups/git/backup_20241218_020000/myrepo.git
git fsck

Advanced Options

Email Notifications on Failure

Create /etc/systemd/system/git-backup-notify@.service:

[Unit]
Description=Backup notification for %i

[Service]
Type=oneshot
ExecStart=/usr/bin/bash -c 'echo "Backup %i failed" | mail -s "Backup Alert" admin@example.com'

Edit /etc/systemd/system/git-backup.service and add:

[Unit]
OnFailure=git-backup-notify@%n.service

Remote Backup

Update BACKUP_PATH in config to use SSH:

BACKUP_PATH="user@backup-server:/backups/git"

Ensure SSH key authentication is set up for passwordless access.

Priority and Resource Limits

Edit /etc/systemd/system/git-backup.service:

[Service]
# Run with lower priority
Nice=19
IOSchedulingClass=idle

# Limit CPU usage
CPUQuota=50%

# Memory limit
MemoryMax=1G

Security Considerations

Service runs as root by default (needed for file access)
Uses NoNewPrivileges=yes and PrivateTmp=yes for security hardening
Consider running as dedicated backup user with appropriate permissions
Secure backup destination (proper filesystem permissions)
Consider encrypting backup destination
For remote backups, use SSH key authentication
Regularly test restore procedures

Understanding systemd Benefits

Why systemd over cron?

Better logging: All output goes to journald (structured logging)
Status monitoring: systemctl status shows current state
Dependency handling: Service can depend on network, mounts, etc.
Failure recovery: Built-in retry on failure
Persistent timers: Missed backups run on next boot
Resource control: Easy CPU/memory limits
Notification: Built-in failure notifications

Persistent Timers

The Persistent=true option means:

If server was off when backup should have run
Backup runs immediately after boot
Ensures you don't miss backups due to downtime

Uninstallation

# Stop and disable timer
sudo systemctl disable --now git-backup.timer

# Remove systemd units
sudo rm /etc/systemd/system/git-backup.{service,timer}
sudo systemctl daemon-reload

# Remove script and config
sudo rm /usr/local/bin/git-backup
sudo rm -rf /etc/git-backup

# Optionally remove backups
# sudo rm -rf /mnt/backups/git

License

Free to use and modify for your needs.

Name		Name	Last commit message	Last commit date
Latest commit History 3 Commits
.gitignore		.gitignore
LICENSE		LICENSE
Makefile		Makefile
README.md		README.md
backup-config.conf		backup-config.conf
git-backup.service		git-backup.service
git-backup.timer		git-backup.timer
install.sh		install.sh
main.go		main.go

License

kaputi/gitBackup

Folders and files

Latest commit

History

Repository files navigation

Git Repository Backup System (systemd)

Features

Installation

Quick Install

Manual Install

Configuration

Configuration Options

Usage

Enable Automatic Backups

Manual Backup

View Logs

Check Backup Status

Customizing the Schedule

Default (Daily at Midnight)

Every 6 Hours

Twice Daily (2 AM and 2 PM)

Weekly (Sunday at 3:00 AM)

Specific Days (Monday, Wednesday, Friday at 1 AM)

Backup Structure

How Rotation Works

How Compression Works

Monitoring

Check Recent Backups

View Last Backup Run

Check Backup Size

List All Backups

Service Management Commands

Restoring from Backup

Restore from Uncompressed Backup

Restore from Compressed Backup

Troubleshooting

Check Service Logs for Errors

Test Backup Manually

Permission Issues

Timer Not Running

Disk Space

View Systemd Timer Details

Verify Backup Integrity

Advanced Options

Email Notifications on Failure

Remote Backup

Priority and Resource Limits

Security Considerations

Understanding systemd Benefits

Why systemd over cron?

Persistent Timers

Uninstallation

License

About

Resources

License

Uh oh!

Stars

Watchers

Forks

Releases

Packages 0

Languages

Packages