Harry Tang

Deploy MariaDB Galera with MaxScale on Kubernetes

MariaDB K8s
MariaDB K8s

Introduction

MariaDB Galera is a multi-primary database cluster that offers a high-availability solution for those running high-workload, production-ready environments. This article explains how I deployed MariaDB Galera with MaxScale on my Kubernetes cluster.

Prerequisites

  • A Kubernetes cluster with at least three worker nodes.
  • Sealed Secrets installed.
  • FluxCD installed.
  • Cloudflare Tunnel (optional).

Step-by-step Guide

I used FluxCD to commit my YAML files to Git, as I follow the GitOps approach. However, you can also use standard Helm commands for these steps.

  1. Install MaraDB Operator

    The MariaDB Operator simplifies the deployment and configuration of MariaDB servers in Kubernetes. I installed it using FluxCD in the mariadb-operator namespace:

    ---
apiVersion: source.toolkit.fluxcd.io/v1
kind: HelmRepository
metadata:
  name: mariadb-operator
  namespace: mariadb-operator
spec:
  interval: 24h
  url: https://helm.mariadb.com/mariadb-operator
---
apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
metadata:
  name: mariadb-operator-crds
  namespace: mariadb-operator
spec:
  interval: 24h
  chart:
    spec:
      chart: mariadb-operator-crds
      version: '^0.37.1'
      sourceRef:
        kind: HelmRepository
        name: mariadb-operator
        namespace: mariadb-operator
      interval: 24h
---
apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
metadata:
  name: mariadb-operator
  namespace: mariadb-operator
spec:
  interval: 24h
  chart:
    spec:
      chart: mariadb-operator
      version: '^0.37.1'
      sourceRef:
        kind: HelmRepository
        name: mariadb-operator
        namespace: mariadb-operator
      interval: 24h

  2. Create a SealedSecret for the MariaDB username and password

    If Sealed Secrets is not installed, you can create a standard Kubernetes secret instead. In this case, I opted for the first option:

    kubectl -n mariadb create secret generic mariadb --from-literal=mariadb-username=mariadb --from-literal=mariadb-password=$(openssl rand -base64 24 | tr -d '/+=' | cut -c1-32
) --dry-run=client -o yaml | kubeseal --format yaml > mariadb.sealed-secret.yaml

  3. Deploy MariaDB Galera with MaxScale

    MaxScale is an advanced database proxy, router, and load balancer, built specifically for MariaDB by its developers. To achieve full high availability (HA), I deployed two replicas of MaxScale and a three-replica MariaDB Galera cluster:

    ---
apiVersion: k8s.mariadb.com/v1alpha1
kind: MaxScale
metadata:
  name: maxscale-galera
  namespace: mariadb
spec:
  replicas: 2
  mariaDbRef:
    name: mariadb-galera
  admin:
    port: 8989
    guiEnabled: true
  monitor:
    name: mariadb-monitor
    module: galeramon
    interval: 2s
    cooperativeMonitoring: majority_of_all
    params:
      disable_master_failback: 'false'
      available_when_donor: 'false'
      disable_master_role_setting: 'false'
  config:
    sync:
      database: mysql
      interval: 5s
      timeout: 10s
---
apiVersion: k8s.mariadb.com/v1alpha1
kind: MariaDB
metadata:
  name: mariadb-galera
  namespace: mariadb
spec:
  maxScaleRef:
    name: maxscale-galera
  galera:
    enabled: true
    config:
      reuseStorageVolume: true
    agent:
      basicAuth:
        enabled: true
  replicas: 3
  storage:
    size: 8Gi
  database: mariadb
  username: mariadb
  passwordSecretKeyRef:
    name: mariadb
    key: mariadb-password

  4. Securely expose the MaxScale GUI using Cloudflare Tunnel

    This step is optional. I used Cloudflare Tunnel to expose the MaxScale GUI, allowing easy access to a user-friendly dashboard for my MariaDB Galera cluster:

    ...
cloudflare:
  ingress: 
    - hostname: maxscale.harrytang.com
      service: http://maxscale-galera-gui.mariadb:8989
...

    MariaDB MaxScale GUI

Conclusion

Deploying MariaDB Galera on Kubernetes has never been easier thanks to the MariaDB Operator. I hope this article helps you set up your high-availability database cluster in Kubernetes.

References

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