What is kamal-backup?

Kamal-backup is a Ruby gem that adds automated, scheduled database and file backups to Rails web applications deployed with Kamal. Kamal is a deployment tool that uses Docker containers on your own servers rather than a managed cloud platform, and kamal-backup plugs into that system as what Kamal calls an "accessory", an add-on container that runs alongside your main application. The problem it solves is that self-hosted Rails apps typically need recurring backups of their PostgreSQL, MySQL/MariaDB, or SQLite database, plus any files uploaded through Rails Active Storage (the built-in file attachment system), but setting this up properly is often a separate operations project. Kamal-backup makes it a one-config addition. Under the hood it uses restic, a backup tool that produces encrypted and deduplicated snapshots stored in S3-compatible object storage, a restic REST server, or a local filesystem location. Deduplication means only the changes since the last backup are stored, saving storage space. You configure a schedule in seconds, point it at your database and storage paths, and the container handles the rest automatically. It also includes restore drills, test restores to verify your backups actually work, and a command to generate JSON evidence of backup status for security reviews. A developer running a self-hosted Rails app with Kamal who wants reliable, encrypted, automated backups without building a separate backup system would use this.