rsync-loop

A simple Rust tool to automate repeated rsync transfers with SSH password authentication, featuring scheduled intervals and progress tracking.

What is this?

rsync-loop is a command-line utility that automates repeated rsync transfers with SSH password authentication (via sshpass) at configurable intervals. It’s designed to keep files in sync continuously rather than waiting for a one-time transfer, making it ideal for scenarios where:

• New files are generated incrementally (e.g., cryo-EM data collection, log file generation, or real-time sensor data) – sync files as they appear, finishing transfers by the time all data generation completes, saving critical time.
• Periodic backups to remote servers need consistent scheduling without manual intervention.
• Development workflows require frequent syncing between local and remote environments (e.g., updating web assets or application code).
• You need to monitor transfer reliability over time (with built-in success/failure tracking).
• Repetitive file transfer tasks (like syncing to multiple destinations) need automation.

By running rsync repeatedly at set intervals, it ensures your files stay up-to-date across locations without waiting for a full dataset to be generated.

Features

✅ Runs rsync multiple times with a single command
✅ Configurable wait time between sync rounds
✅ Tracks success/failure of each transfer
✅ Clean progress display with countdown timer
✅ Graceful exit on Ctrl+C
✅ can accept all rsync parameters through passthrough arguments

Prerequisites

• Rust (for building from source)
• sshpass (required for password-based SSH authentication)
• rsync (obviously, since we're repeating it)

Install from crates.io (recommand):

cargo install rsync_loop

Install dependencies on Debian/Ubuntu:

sudo apt-get install sshpass

Install dependencies on RHEL/Centos/Rocky/Almal Linux:

sudo yum install sshpass

On macOS (using Homebrew):

brew install sshpass

Installation

From Source

# Clone the repository
git clone https://github.com/elemeng/rsync_loop.git
cd rsync_loop

# Build the binary
cargo build --release

# Install to your system (optional)
sudo cp target/release/rsync_loop /usr/local/bin/

Usage

Basic syntax:

rsync_loop -p <ssh-password> [OPTIONS] -- <rsync-arguments>

Options

Option	Short	Long	Description	Default
Password	-p	--password	SSH password (required)	-
Times	-t	--times	Number of sync rounds	20
Wait	-w	--wait	Seconds to wait between rounds	300 (5 minutes)

Examples

1. Basic remote backup, running 10 times with 10-minute intervals:

rsync_loop -p "mypass" -t 10 -w 600 -- -avz /local/files/ user@remote:/backup/location/

2. Sync a website directory every 30 minutes, 5 times total:

rsync_loop -p "serverpass" -t 5 -w 1800 -- -avz --delete ./public/ webuser@example.com:/var/www/html/

3. Test connection reliability with minimal transfers:

rsync_loop -p "testpass" -t 100 -w 60 -- -av --dry-run user@host:/remote/path/ /tmp/

Output Example

===== Round 1/5 =====
sending incremental file list
file1.txt
file2.txt

sent 123 bytes  received 45 bytes  112.00 bytes/sec
total size is 7890  speedup is 53.99
Round 1 succeeded.
Next sync in 04:59

Notes

• Security Warning: Using passwords on the command line may expose them in process lists. Consider using SSH keys for better security when possible.
• All rsync arguments work as normal - this tool simply wraps rsync with scheduling functionality
• The countdown timer shows remaining time in MM:SS format
• Ctrl+C will exit gracefully and show final statistics

License

MIT