backup-client

A containerized SSH backup server built on Alpine Linux, designed to provide secure remote backup access using SSH/SFTP protocols.

Features

• 🔐 Secure SSH Access: Automated SSH server setup with configurable authentication
• 🐳 Docker Ready: Multi-architecture support (linux/amd64, linux/arm64)
• 📦 BorgBackup Integration: Built-in backup solution support
• ⚙️ Dynamic Configuration: Real-time SSH config monitoring and reloading
• 🔄 CI/CD Pipeline: Automated builds via Drone CI

Quick Start

docker run -p 20022:20022 -v /backup/data:/home/backup safebox/backup-client

Configuration
Environment Variables
Variable	Default	Description
SSH_PORT	20022	SSH server listening port
SSH_USER	backup	Backup user name
SSH_PASSWORD	backup	User password for authentication

How it Works
The container automatically:

User Setup: Creates the backup user with configured credentials
SSH Configuration: Generates host keys (RSA and Ed25519) if not present
Server Start: Launches SSH daemon with SFTP support
Monitoring: Watches for configuration changes and reloads SSH server as needed
Key Components
Dockerfile: Alpine-based image with OpenSSH, su-exec, and BorgBackup
start_backup.sh: Main entrypoint script handling SSH setup and monitoring
.drone.yml: CI/CD pipeline for multi-architecture builds
Architecture
┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
│   SSH Client    │───▶│  Docker Container │───▶│  Backup Storage │
│  (Your backup   │    │   (Alpine Linux)  │    │   (/home/backup)│
│   application)  │    │                   │    │                 │
└─────────────────┘    └──────────────────┘    └─────────────────┘
                              │

│  (Your backup   │    │   (Alpine Linux)  │    │   (/home/backup)│
Security Features
Host Key Persistence: SSH host keys are generated once and persisted
Configurable Authentication: Supports both password and public key authentication
User Isolation: Runs SSH daemon as non-root user
SFTP Subsystem: Secure file transfer protocol support
Development
Building Locally
Testing
CI/CD
The project uses Drone CI for automated builds:

Development builds: Push to registry.dev.format.hu/backup-client
Release builds: Tag events push to safebox/backup-client on DockerHub
Multi-architecture: Supports both AMD64 and ARM64 platforms
Contributing
Fork the repository
Create a feature branch
Make your changes
Test the Docker build
Submit a pull request
License
This project is open source. Please check the license file for details.