Rook Cloud-Native Storage Orchestrator

Rook is an open-source cloud-native storage orchestrator for Kubernetes, turning distributed storage systems into self-managing, self-scaling, self-healing storage services by deeply integrating them with the Kubernetes API. Created by Bassam Tabbara and Jared Watts at Replicated in 2016, Rook was one of the first CNCF graduated storage projects (graduated in 2020), with over 12,000 stars as of 2026. Key features include: Ceph storage provider (the primary and most mature provider, managing Ceph clusters on Kubernetes including RADOS Block Device for block storage, CephFS for shared file systems, and RADOS Gateway for S3-compatible object storage), operator pattern (custom controllers implementing Kubernetes operator pattern, continuously observing and reconciling storage cluster state), custom resource definitions (declarative management of storage clusters, pools, file systems, object stores, and bucket claims via CRDs), automated operations (automatic cluster bootstrap, OSD provisioning on available devices, rebalancing on node addition or removal, and failure recovery without manual intervention), block storage (RBD-backed PersistentVolumes with dynamic provisioning, snapshotting, cloning, and expansion), shared file system (CephFS-backed ReadWriteMany volumes for shared access across multiple pods), object storage (S3-compatible object stores via RADOS Gateway with bucket claims and lifecycle management), NFS provider (managing NFS-Ganesha servers for cross-platform file sharing), monitoring (Prometheus metrics for cluster health, OSD status, pool utilization, and IOPS, plus Grafana dashboards), upgrade management (rolling upgrades of Ceph and Rook versions without downtime), security (Pod Security Policies, Security Context Constraints, and network policies for multi-tenant isolation), and disaster recovery (backup and restore of Ceph monitor data and OSD metadata for full cluster recovery).