Kubernetes Operators for MariaDB
Operators basically instruct Kubernetes about how to manage a certain technology. Kubernetes comes with some default operators, but it is possible to create custom operators. Operators created by the community can be found on OperatorHub.io.
Custom Operators
Kubernetes provides a declarative API. To support a specific (i.e. MariaDB) technology or implement a desired behavior (i.e. provisioning a replica), we extend Kubernetes API. This involves creating two main components:
- A custom resource.
- A custom controller.
A custom resource adds an API endpoint, so the resource can be managed via the API server. It includes functionality to get information about the resource, like a list of the existing servers.
A custom controller implements the checks that must be performed against the resource to check if its state should be corrected using the API. In the case of MariaDB, some reasonable checks would be verifying that it accepts connections, replication is running, and a server is (or is not) read only.
MariaDB Operator
mariadb-operator is a Kubernetes operator that allows you to run and operate MariaDB in a cloud native way. It aims for declaratively managing your MariaDB using Kubernetes CRDs rather than imperative commands.
It's available in both Artifact Hub and Operator Hub and supports the following features:
- Provisioning highly configurable MariaDB servers.
- Single master HA via SemiSync replication. Primary switchover. Automatic primary failover
- Take and restore backups. Scheduled backups. Backup rotation
- Bootstrap new instances from backups and volumes (PVCs, NFS ...)
- Manage users, grants and logical databases
- Configure connections for your applications
- Orchestrate sql scripts
- Prometheus metrics
- Validation webhooks to provide CRD inmutability
- Additional printer columns to report the current CRD status
- CRDs designed according to the Kubernetes API conventions
- GitOps friendly
- Multi-arch distroless based image
- Install it using kubectl, helm or OLM
This operator is open source and released under the terms of the MIT license. The source code is available on GitHub.
Other Operators
If you know about other MariaDB operators, feel free to add them to this page (see Writing and Editing Knowledge Base Articles).
MySQL and Percona Server operators should work as well, though some changes may be necessary to fix incompatibilities or take advantage of certain MariaDB features.
Content initially contributed by Vettabase Ltd.