This sample show how to use init container to download init.sql file and initialize mysql database using this file

mysql-initialization-with-init-container.yaml

# this pvc will be used to store downloaded init.sql file
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: init-script
spec:
  accessModes:
    - ReadWriteOnce
  volumeMode: Filesystem
  resources:
    requests:
      storage: 50Mi
---
# this pvc will be used to store mysql database
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: mysql-data-pvc
spec:
  accessModes:
    - ReadWriteOnce
  volumeMode: Filesystem
  resources:
    requests:
      storage: 1Gi
---
apiVersion: apps/v1 
kind: Deployment
metadata:
  name: mysql-init-demo
spec:
  selector:
    matchLabels:
      app: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: mysql
    spec:
      initContainers:  # this init container download init.sql file using "curl -o <downloaded file name with path> <download url>" command.
      - name: init-script-downloader
        image: appropriate/curl
        args:
          - "-o"
          - "/tmp/data/init.sql" # we are saving downloaded file as init.sql in /tmp/data directory
          - "https://raw.githubusercontent.com/kubedb/mysql-init-scripts/master/init.sql" # download url
        volumeMounts:
        - name: init-script # mount the volume where downloaded file will be saved
          mountPath: /tmp/data
      containers:
      - image: mysql:5.6
        name: mysql
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: password
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: data
          mountPath: /var/lib/mysql
        - name: init-script
          mountPath: /docker-entrypoint-initdb.d # we are mounting init-script volume in this directory. so init.sql file will be available here.
      volumes:
      - name: init-script # this volume holds downloaded init.sql file.
        persistentVolumeClaim:
          claimName: init-script
      - name: data # this volume will be used for database storage.
        persistentVolumeClaim:
          claimName: mysql-data-pvc

hi Hossainemruz,

Thanks for sharing this yaml file, it's really helping me in preparing my application with initialize mysql database in kubernetes. I have a question for initcontainer part

• name: init-script-downloader
  image: appropriate/curl
  args:
  - "-o"
  - "/tmp/data/init.sql" # we are saving downloaded file as init.sql in /tmp/data directory
  - "https://raw.githubusercontent.com/kubedb/mysql-init-scripts/master/init.sql" # download url

How should i write above part if i want to download let's say 3 files from 3 url and restore them all in mysql container, is it possible ?

Thanks
Aris

@loobenfeld you can do that. Just pass multiple arguments.
This should work:

args:
  - "-o"
  - "name-1"
  - "url-1" # download url
  - "-o"
  - "name-2"
  - "url-2" # download url
  - "-o"
  - "name-3"
  - "url-3" # download url

Ref: https://tecadmin.net/curl-files-download-examples/