How to initialize mysql container when created on Kubernetes?

Question

I want to set initial data on MySQL of container. In docker-compose.yml, such code can create initial data when running container.

volumes:   - db:/var/lib/mysql   - "./docker/mysql/conf.d:/etc/mysql/conf.d"   - "./docker/mysql/init.d:/docker-entrypoint-initdb.d" 

However, how can I create initial data on Kubernetes when running?

Answer 1

According to the MySQL Docker image README, the part that is relevant to data initialization on container start-up is to ensure all your initialization files are mount to the container's /docker-entrypoint-initdb.d folder.

You can define your initial data in a ConfigMap, and mount the corresponding volume in your pod like this:

apiVersion: v1 kind: Pod metadata:   name: mysql spec:   containers:   - name: mysql     image: mysql             ports:       - containerPort: 3306     volumeMounts:       - name: mysql-initdb         mountPath: /docker-entrypoint-initdb.d   volumes:     - name: mysql-initdb       configMap:         name: mysql-initdb-config --- apiVersion: v1 kind: ConfigMap metadata:   name: mysql-initdb-config data:   initdb.sql: |     CREATE TABLE friends (id INT, name VARCHAR(256), age INT, gender VARCHAR(3));     INSERT INTO friends VALUES (1, 'John Smith', 32, 'm');     INSERT INTO friends VALUES (2, 'Lilian Worksmith', 29, 'f');     INSERT INTO friends VALUES (3, 'Michael Rupert', 27, 'm'); 

Answer 2

First: create persistent volume that contains your SQL scripts

kind: PersistentVolume apiVersion: v1 metadata:   name: mysql-initdb-pv-volume   labels:     type: local     app: mysql spec:   storageClassName: manual   capacity:     storage: 1Mi   accessModes:     - ReadOnlyMany   hostPath:     path: "/path/to/initdb/sql/scripts" --- kind: PersistentVolumeClaim apiVersion: v1 metadata:   name: mysql-initdb-pv-claim   labels:     app: mysql spec:   storageClassName: manual   accessModes:     - ReadOnlyMany   resources:     requests:       storage: 1Mi 

Note: assume that you have your SQL scripts in /path/to/initdb/sql/scripts

Second: mount the volume to /docker-entrypoint-initdb.d

apiVersion: extensions/v1beta1 kind: Deployment metadata:   name: mysql spec:   replicas: 1   template:     metadata:       labels:         app: mysql     spec:       containers:         - name: mysql           image: mysql           imagePullPolicy: "IfNotPresent"           ports:             - containerPort: 3306           volumeMounts:             - mountPath: /docker-entrypoint-initdb.d               name: mysql-initdb       volumes:         - name: mysql-initdb           persistentVolumeClaim:             claimName: mysql-initdb-pv-claim 

That's it.

Note: this applies to PostgreSQL too.