Build a docker image for backup Mysql database to AWS S3

In this tutorial, we will build a docker image for cronjob on Kubernetes to auto backup Mysql database.

Let’s build a docker image with Dockerfile:

FROM mariadb:latest

WORKDIR /app
RUN apt-get update && apt-get install -y curl unzip python3 python3-venv

RUN ln -s /usr/bin/python3 /usr/bin/python
RUN curl "https://s3.amazonaws.com/aws-cli/awscli-bundle.zip" -o "awscli-bundle.zip" && unzip awscli-bundle.zip && ./awscli-bundle/install -i /usr/local/aws -b /usr/local/bin/aws
COPY backup_to_s3.sh ./backup_to_s3.sh

ENTRYPOINT [ "./backup_to_s3.sh" ]

In this Dockerfile, we use mariadb:latest to call mysqldump . In addition, we also install aws-cli to be able to interact with AWS using the command line.

File backup_to_s3.sh

#!/bin/bash

# Dump and upload to S3
FILE_NAME=backup-$(date "+%Y-%m-%d-%H%M%S").sql
mysqldump -h $DATABASE_HOST -P 3306 -u $DATABASE_USER --password=$DATABASE_PASSWORD $DATABASE_NAME > $FILE_NAME
aws s3 cp $FILE_NAME s3://$AWS_S3_BUCKET/$FILE_NAME

Don’t forget run chmod a+x backup_to_s3.sh

docker build -t backup_mysql:latest .

I have posted this docker image to my Docker Hub account osbkca/backup_mysql

Deploy a CronJob to Kubernetes
mysql-cronjob-backup.yaml

apiVersion: batch/v1
kind: CronJob
metadata:
  labels:
    app: auto-backup-mysql
  name: auto-backup-mysql
spec:
  jobTemplate:
    spec:
      template:
        spec:
          affinity: {}
          containers:
          - env:
            - name: DATABASE_HOST
              value: <change_value>
            - name: DATABASE_USER
              value: <change_value>
            - name: DATABASE_PASSWORD
              value: <change_value>
            - name: DATABASE_NAME
              value: <change_value>
            - name: AWS_S3_BUCKET
              value: <change_value>
                        - name: AWS_ACCESS_KEY_ID
              value: <change_value>
            - name: AWS_SECRET_ACCESS_KEY
              value: <change_value>
            image: osbkca/backup_mysql:latest
            imagePullPolicy: Always
            name: backup-container

  schedule: 12 09 * * *
  successfulJobsHistoryLimit: 3
  suspend: false

To deploy:

kubectl apply -f mysql-cronjob-backup.yaml

Enjoy it! More Info here