Self-hosted, S3-compatible object storage with a web console.

Cairn is a self-hosted object storage solution that offers S3 compatibility. It stores object data as plain files on the filesystem and manages metadata using an embedded SQLite database, eliminating the need for external database or storage services. Designed for single-node operation, it supports asynchronous bucket replication for redundancy across hosts.

• S3 Compatibility: Supports multipart uploads, range reads, checksums, versioning, presigned URLs, tagging, CORS, lifecycle expiration, and Object Lock.
• Web Console: Provides a user interface for managing buckets, users, and policies. Users can upload, preview, and share objects, as well as inspect usage, metrics, and replication status.
• Security Features: Includes native TLS, bucket policies, scoped temporary credentials, SSE-S3, and transparent object encryption at rest. The AWS KMS interface is supported for key labels backed by the node's master-key ring.
• Storage and Operations: Offers block compression, durable writes, asynchronous replication, webhooks, S3 import, integrity checks, backup/restore capabilities, and Prometheus metrics.

Installation is straightforward, with a provided script for setup on Linux systems with compatible kernels. Local testing is facilitated using Docker, with clear instructions for setting up the master key, running the container, and interacting via the AWS CLI.

The project emphasizes clear configuration through environment variables and provides detailed documentation on operations, backup, restore, upgrades, replication, and troubleshooting. It is licensed under the Apache-2.0 license.