How to deploy MySQL-Server Docker using Helm Chart in Kubernetes with Persistent Volume!

1. Pull MySQL Server docker image from Docker repository, tag it as
   appreciate, then push to private repository.

   docker pull mysql/mysql-server:5.7.21 docker tag
   mysql/mysql-server:5.7.21 qio01:5000/mysql-server:latest 
   docker push

2. Exec helm init to initialize Helm Chart.

3. Edit Chart.yaml. This is optional, it is just to provide information of your deployment and make it more professional.

   description: MySQL is the world's most popular open source database. With its proven performance, reliability, and ease-of-use, MySQL has become the leading choice of database for web applications of all sorts, ranging from personal websites and small online shops all the way to large-scale, high profile web operations like Facebook, Twitter, and YouTube.
   home: http://www.mysql.com
   icon: https://www.mysql.com/common/logos/logo-mysql-170x115.png
   keywords:
   - component=repo.mysql.com/yum/mysql-5.7-community/docker/x86_64/mysql-community-server-minimal-5.7.21-1.el7.x86_64.rpm
   maintainers:
   - email: hiroshifuu@outlook.com
     name: Feng Hao
   name: mysqldb
   sources:
   - https://hub.docker.com/r/mysql/mysql-server/
   version: 1.0

4. Edit values.yaml. You may want to specific the password, by setting mysqldbPassword: password.

   image:
     pullPolicy: IfNotPresent
     repository: qio01:5000/mysql-server
     tag: latest
   persistence:
     accessMode: ReadWriteOnce
     enabled: true
     size: 40Gi
     storageClass: standard
   resources:
     requests:
       memory: 512Mi
       cpu: 500m
   serviceType: ClusterIP
   mysqldbPassword: password

5. Create secret.yaml. If you have defined the mysqlRootPassword, the password will be configured. You could define a different password for root in the values.yaml by setting mysqlRootPassword.

   apiVersion: v1
   kind: Secret
   metadata:
     name: {{ template "fullname" . }}
     labels:
       app: {{ template "fullname" . }}
       chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
       release: "{{ .Release.Name }}"
       heritage: "{{ .Release.Service }}"
   type: Opaque
   data:
     mysqldb-root-password: {{ default "" .Values.mysqlRootPassword | b64enc | quote }}
     mysqldb-password: {{ default "" .Values.mysqldbPassword | b64enc | quote }}
   {{- if .Values.mysqlRootPassword }}
     data-source-name: {{ printf "root%s@(localhost:3306)/" .Values.mysqlRootPassword | b64enc | quote}}
   {{- else }}
     data-source-name: {{ printf "root@(localhost:3306)/" | b64enc | quote}}
   {{- end }}

6. Edit deployment.yaml. A few things you might be interested to look at. The env configurations. MySQL user password, root password, default database, and allow for empty password all can be found here. The most important configuration is the mountPath of volumeMounts. This is for persistent storage, you need to set the mountPath correctly, different MySQL distribution will use different path.

   apiVersion: extensions/v1beta1
   kind: Deployment
   metadata:
     name: {{ template "fullname" . }}
     labels:
       app: {{ template "fullname" . }}
       chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
       release: "{{ .Release.Name }}"
       heritage: "{{ .Release.Service }}"
   spec:
     template:
       metadata:
         labels:
           app: {{ template "fullname" . }}
           release: {{ .Release.Name }}
           component: "{{.Release.Name}}"
           nautilian.snapshot.enabled: "true"
       spec:
         containers:
         - name: {{ template "fullname" . }}
           image: {{ .Values.image.repository}}:{{ .Values.image.tag}}
           imagePullPolicy: {{ .Values.image.pullPolicy }}
           env:
           - name: MYSQLDB_ROOT_PASSWORD
             valueFrom:
               secretKeyRef:
                 name: {{ template "fullname" . }}
                 key: mysqldb-root-password
           - name: MYSQLDB_USER
             value: {{ default "" .Values.mysqldbUser | quote }}
           - name: MYSQLDB_PASSWORD
             valueFrom:
               secretKeyRef:
                 name: {{ template "fullname" . }}
                 key: mysqldb-password
           - name: MYSQLDB_DATABASE
             value: {{ default "" .Values.mysqldbDatabase | quote }}
           - name: ALLOW_EMPTY_PASSWORD
             value: "yes"
           ports:
           - name: mysql
             containerPort: 3306
           livenessProbe:
             exec:
               command:
               - mysqladmin
               - ping
             initialDelaySeconds: 30
             timeoutSeconds: 5
           readinessProbe:
             exec:
               command:
               - mysqladmin
               - ping
             initialDelaySeconds: 5
             timeoutSeconds: 1
           resources:
   {{ toYaml .Values.resources | indent 10 }}
           volumeMounts:
           - name: data
             mountPath: /var/lib/mysql
         volumes:
         - name: config
           configMap:
             name: {{ template "fullname" . }}
         - name: data
         {{- if .Values.persistence.enabled }}
           persistentVolumeClaim:
             claimName: {{ .Values.persistence.existingClaim | default (include "fullname" .) }}
         {{- else }}
           emptyDir: {}
         {{- end -}}

7. Create svc.yaml to create a service in kubernetes.

   apiVersion: v1
   kind: Service
   metadata:
     name: {{ template "fullname" . }}
     labels:
       app: {{ template "fullname" . }}
       chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
       release: "{{ .Release.Name }}"
       heritage: "{{ .Release.Service }}"
   spec:
     type: {{ .Values.serviceType }}
     ports:
     - name: mysql
       port: 3306
       targetPort: 3306
     selector:
       app: {{ template "fullname" . }}

8. Create pvc.yaml for the persistent volume.

   {{- if and .Values.persistence.enabled (not .Values.persistence.existingClaim) }}
   kind: PersistentVolumeClaim
   apiVersion: v1
   metadata:
     name: {{ template "fullname" . }}
     labels:
       app: {{ template "fullname" . }}
       chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
       release: "{{ .Release.Name }}"
       heritage: "{{ .Release.Service }}"
     annotations:
     {{- if .Values.persistence.storageClass }}
       volume.beta.kubernetes.io/storage-class: {{ .Values.persistence.storageClass | quote }}
     {{- else }}
       volume.alpha.kubernetes.io/storage-class: default
     {{- end }}
   spec:
     accessModes:
       - {{ .Values.persistence.accessMode | quote }}
     resources:
       requests:
         storage: {{ .Values.persistence.size | quote }}
   {{- end }}

9. Deploy using helm install.

   $ helm install <chart_name> --name <release-name> --namespace <name-space> name

10. Login to the shell of the Pod to do MySQL configurations. Grant all privileges on that database and (in the future) tables. WITH GRANT OPTION creates a MySQL user that can edit the permissions of other users.

    ALTER USER 'root'@'localhost' IDENTIFIED BY 'password';
    GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'password';
    GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;
    FLUSH PRIVILEGES;