How to initialize mysql container when created on Kubernetes?
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');
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.