MySQL on Kubernetes

 

How to Deploy MySQL on Kubernetes

I found the nice article and learning here 

https://pycon2019.container.training/#169

https://container.training/kube-selfpaced.yml.html#129

Prepare the environment

Following this tutorial, you need to have Minikube installed on your Ubuntu Linux.

You can verify whether the Minikube has been successfully up and running by the following command:

$ minikube status

Output:

minikube
type: Control Plane
host: Running
kubelet: Running
apiserver: Running
kubeconfig: Configured

Create Secret for MySQL

Kubernetes uses Secret to store and manage sensitive information such as passwords, ssh keys and OAuth tokens. In this tutorial, we use base64 encoded to store 'MYSQL_ROOT_PASSWORD'. For example:

$ echo -n 'admin' | base64

Output:

YWRtaW4=

Create a mysql-secret.yaml file for MySQL that will be mapped as an environment variable as follows:

apiVersion: v1
kind: Secret
metadata:
  name: mysql-pass
type: Opaque
data:
  password: YWRtaW4=

Apply the manifest:

$ kubectl create -f mysql-secret.yaml

secret/mysql-pass created

Verify that the Secret has just been created successfully:

$ kubectl get secrets

NAME                  TYPE                                  DATA   AGE
default-token-l7t7b   kubernetes.io/service-account-token   3      4h24m
mysql-pass            Opaque                                1      1m

Deploy MySQL

Create the mysql-pod.yaml file to deploy MySQL pod on Kubernetes cluster:

apiVersion: v1
kind: Pod
metadata:
  name: k8s-mysql
  labels:
    name: lbl-k8s-mysql
spec:
  containers:
  - name: mysql
    image: mysql:latest
    env:
    - name: MYSQL_ROOT_PASSWORD
      valueFrom:
        secretKeyRef:
          name: mysql-pass
          key: password
    ports:
    - name: mysql
      containerPort: 3306
      protocol: TCP
    volumeMounts:
    - name: k8s-mysql-storage
      mountPath: /var/lib/mysql
  volumes:
  - name: k8s-mysql-storage
    emptyDir: {}

Apply the manifest file:

$ kubectl create -f mysql-pod.yaml

pod/k8s-mysql created

Verify that the pod is running:

$ kubectl get pod

NAME        READY   STATUS    RESTARTS   AGE
k8s-mysql   1/1     Running   0          30s

Now, we can connect to the k8s-mysql pod:

$ kubectl exec k8s-mysql -it -- bash

root@k8s-mysql:/# echo $MYSQL_ROOT_PASSWORD
admin
root@k8s-mysql:/# mysql --user=root --password=$MYSQL_ROOT_PASSWORD
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 8.0.22 MySQL Community Server - GPL

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

mysql> 

Kubernetes use Service to expose pods to other pods or external systems. We will use the following manifest file mysql-service.yaml to make the k8s-mysql pod be reachable:

apiVersion: v1
kind: Service
metadata:
  name: mysql-service
  labels:
    name: lbl-k8s-mysql
spec:
  ports:
  - port: 3306
  selector:
    name: lbl-k8s-mysql
  type: ClusterIP

Apply the manifest to create the service:

$ kubectl create -f mysql-service.yaml

service/mysql-service created

Verify that the service has been successfully created:

$ kubectl get svc

NAME            TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
kubernetes      ClusterIP   10.96.0.1               443/TCP    5h4m
mysql-service   ClusterIP   10.110.22.182           3306/TCP   30s