一、概述
MySQL是一個關系型數據庫管理系統，由瑞典MySQL AB 公司開發，屬于 Oracle 旗下產品。MySQL 是最流行的關系型數據庫管理系統之一，在 WEB 應用方面，MySQL是最好的 RDBMS (Relational Database Management System，關系數據庫管理系統) 應用軟件之一。這里主要講mysql部署在k8s上，mysql部署在k8s上的優勢主要有以下幾點：
- 資源隔離
- 動態彈性擴縮容
- 環境一致性
- 運維方便
官方文檔：https://docs.oracle.com/en-us/iaas/mysql-database/doc/getting-started.html
MySQL 原理介紹也可以參考我這篇文章：MySQL原理介紹
二、開始部署（一主兩從）
1）添加源 helm repo add bitnami https://charts.bitnami.com/bitnami helm pull bitnami/mysql tar -xf mysql-9.3.3.tgz 2）修改配置
- 修改mysql/values.yaml
... image: registry: myharbor.com repository: bigdata/mysql tag: 8.0.30-debian-11-r15 ... architecture: replication ... primary: persistence: enabled: true size: 10Gi storageClass: "mysql-local-storage" # 目錄需要提前在宿主機上創建 local: - name: mysql-0 host: "local-168-182-110" path: "/opt/bigdata/servers/mysql/data/data1" service: type: NodePort nodePorts: mysql: "30306" secondary: replicaCount: 2 persistence: enabled: true size: 10Gi storageClass: "mysql-local-storage" # 目錄需要提前在宿主機上創建 local: - name: mysql-1 host: "local-168-182-111" path: "/opt/bigdata/servers/mysql/data/data1" - name: mysql-2 host: "local-168-182-112" path: "/opt/bigdata/servers/mysql/data/data1" service: type: NodePort nodePorts: mysql: "30307" ... metrics: ## @param metrics.enabled Start a side-car prometheus exporter ## enabled: true image: registry: myharbor.com repository: bigdata/mysqld-exporter tag: 0.14.0-debian-11-r33
- 添加mysql/templates/pv.yaml
{{- range .Values.primary.persistence.local }} --- apiVersion: v1 kind: PersistentVolume metadata: name: {{ .name }} labels: name: {{ .name }} spec: storageClassName: {{ $.Values.primary.persistence.storageClass }} capacity: storage: {{ $.Values.primary.persistence.size }} accessModes: - ReadWriteOnce local: path: {{ .path }} nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kube.NETes.io/hostname operator: In values: - {{ .host }} --- {{- end }} {{- range .Values.secondary.persistence.local }} --- apiVersion: v1 kind: PersistentVolume metadata: name: {{ .name }} labels: name: {{ .name }} spec: storageClassName: {{ $.Values.secondary.persistence.storageClass }} capacity: storage: {{ $.Values.secondary.persistence.size }} accessModes: - ReadWriteOnce local: path: {{ .path }} nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - {{ .host }} --- {{- end }}
- 添加mysql/templates/storage-class.yaml
kind: StorageClass apiVersion: storage.k8s.io/v1 metadata: name: {{ .Values.primary.persistence.storageClass }} provisioner: kubernetes.io/no-provisioner 3）開始安裝 # 創建持久化目錄 mkdir -p /opt/bigdata/servers/mysql/data/data1 # 先準備好鏡像 Docker pull docker.io/bitnami/mysql:8.0.30-debian-11-r15 docker tag docker.io/bitnami/mysql:8.0.30-debian-11-r15 myharbor.com/bigdata/mysql:8.0.30-debian-11-r15 docker push myharbor.com/bigdata/mysql:8.0.30-debian-11-r15 # mysqld-exporter docker pull docker.io/bitnami/mysqld-exporter:0.14.0-debian-11-r33 docker tag docker.io/bitnami/mysqld-exporter:0.14.0-debian-11-r33 myharbor.com/bigdata/mysqld-exporter:0.14.0-debian-11-r33 docker push myharbor.com/bigdata/mysqld-exporter:0.14.0-debian-11-r33 # 開始安裝 helm install mysql ./mysql -n mysql --create-namespace
NOTES
NAME: mysql LAST DEPLOYED: Mon Sep 19 23:57:18 2022 NAMESPACE: mysql STATUS: deployed REVISION: 1 TEST SUITE: None NOTES: CHART NAME: mysql CHART VERSION: 9.3.3 App VERSION: 8.0.30 ** Please be patient while the chart is being deployed ** Tip: Watch the deployment status using the command: kubectl get pods -w --namespace mysql Services: echo Primary: mysql-primary.mysql.svc.cluster.local:3306 echo Secondary: mysql-secondary.mysql.svc.cluster.local:3306 Execute the following to get the administrator credentials: echo Username: root MYSQL_ROOT_PASSword=$(kubectl get secret --namespace mysql mysql -o jsonpath="{.data.mysql-root-password}" | base64 -d) To connect to your database: 1. Run a pod that you can use as a client: kubectl run mysql-client --rm --tty -i --restart='Never' --image myharbor.com/bigdata/mysql:8.0.30-debian-11-r15 --namespace mysql --env MYSQL_ROOT_PASSWORD=$MYSQL_ROOT_PASSWORD --command -- bash 2. To connect to primary service (read/write): mysql -h mysql-primary.mysql.svc.cluster.local -uroot -p"$MYSQL_ROOT_PASSWORD" 3. To connect to secondary service (read-only): mysql -h mysql-secondary.mysql.svc.cluster.local -uroot -p"$MYSQL_ROOT_PASSWORD" To access the MySQL Prometheus metrics from outside the cluster execute the following commands: kubectl port-forward --namespace mysql svc/mysql-metrics 9104:9104 & curl http://127.0.0.1:9104/metrics
查看pod狀態
kubectl get pods,svc -n mysql -owide
4）測試驗證
【溫馨提示】從庫（slave）是只讀的。就是簡單的讀寫測試，還有就是pod掛了，能否正常拉起等等。這個測試驗證比較簡單。這里就不一步步的演示了。5）Prometheus監控
Prometheus：https://prometheus.k8s.local/targets?search=mysql
可以通過命令查看采集數據
kubectl get --raw http://10.244.0.74:9104/metrics kubectl get --raw http://10.244.1.125:9104/metrics kubectl get --raw http://10.244.2.178:9104/metrics
Grafana：https://grafana.k8s.local/
賬號：admin，密碼通過下面命令獲取
kubectl get secret --namespace grafana grafana -o jsonpath="{.data.admin-password}" | base64 --decode ; echo
導入grafana模板，集群資源監控：7362
官方模塊下載地址：https://grafana.com/grafana/dashboards/
6）卸載 helm uninstall mysql -n mysql kubectl delete pod -n mysql `kubectl get pod -n mysql |awk 'NR>1{print $1}'` --force kubectl patch ns mysql -p '{"metadata":{"finalizers":null}}' kubectl delete ns mysql --force
這里只是實現了mysql 的主從，沒有實現高可用，官方目前沒有出mysql ok k8s高可用的實現方案，雖然網上也有高可用的實現方案，但是我們公司沒真正去落地使用，所以不予評價網上的高可用的方案，有興趣的小伙伴可以去試試，其實mysql在大數據領域一般只是作為元數據存儲，主掛了，影響不是很大。目前也在研究mysql on k8s 的高可用實現方案，如果后期有mysql on k8s高可用真正落地到生產環境中使用，到時候再來分享一下。MySQL on k8s 環境部署就先這里了，有疑問的小伙伴歡迎給我留言~
