Deploying MySQL with ConfigMap, Service, and StatefulSet on Kubernetes (NFS Persistent Storage)

This guide shows how to deploy a MySQL cluster on Kubernetes using NFS for persistent storage, with ConfigMap, Service, and StatefulSet resources.

First, create a ConfigMap (mysql-configmap.yaml) containing master.cnf and slave.cnf:

apiVersion: v1
kind: ConfigMap
metadata:
  name: mysql
  labels:
    app: mysql
data:
  master.cnf: |
    [mysqld]
    log-bin
  slave.cnf: |
    [mysqld]
    super-read-only

Next, define two Services (mysql and mysql-read) to expose the primary and read‑only endpoints:

apiVersion: v1
kind: Service
metadata:
  name: mysql
  labels:
    app: mysql
spec:
  ports:
  - name: mysql
    port: 3306
    clusterIP: None
  selector:
    app: mysql
---
apiVersion: v1
kind: Service
metadata:
  name: mysql-read
  labels:
    app: mysql
spec:
  ports:
  - name: mysql
    port: 3306
  selector:
    app: mysql

Then create a StatefulSet (mysql-statefulset.yaml) that runs three MySQL replicas, mounts the ConfigMap and NFS volume, and includes init containers for configuration and data cloning:

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  serviceName: mysql
  replicas: 3
  template:
    metadata:
      labels:
        app: mysql
    spec:
      initContainers:
      - name: init-mysql
        image: mysql:5.7
        command:
        - bash
        - "-c"
        - |
          set -ex
          [[ `hostname` =~ -([0-9]+)$ ]] || exit 1
          ordinal=${BASH_REMATCH[1]}
          echo [mysqld] > /mnt/conf.d/server-id.cnf
          echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf
          if [[ $ordinal -eq 0 ]]; then
            cp /mnt/config-map/master.cnf /mnt/conf.d/
          else
            cp /mnt/config-map/slave.cnf /mnt/conf.d/
          fi
      containers:
      - name: mysql
        image: mysql:5.7
        env:
        - name: MYSQL_ALLOW_EMPTY_PASSWORD
          value: "1"
        ports:
        - name: mysql
          containerPort: 3306
        volumeMounts:
        - name: data
          mountPath: /var/lib/mysql
          subPath: mysql
        - name: conf
          mountPath: /etc/mysql/conf.d
        resources:
          requests:
            cpu: 500m
            memory: 1Gi
        livenessProbe:
          exec:
            command: ["mysqladmin","ping"]
          initialDelaySeconds: 30
          periodSeconds: 10
          timeoutSeconds: 5
        readinessProbe:
          exec:
            command: ["mysql","-h","127.0.0.1","-e","SELECT 1"]
          initialDelaySeconds: 5
          periodSeconds: 2
          timeoutSeconds: 1
      volumes:
      - name: conf
        emptyDir: {}
      - name: config-map
        configMap:
          name: mysql
      volumeClaimTemplates:
      - metadata:
          name: data
        spec:
          storageClassName: "managed-nfs-storage"
          accessModes: ["ReadWriteOnce"]
          resources:
            requests:
              storage: 10Gi

Apply all manifests with kubectl apply -f . and verify the pods are running using kubectl get pods -l app=mysql --watch .