一，前言

上一篇，介紹基于 k8s 項目部署流程設(shè)計；

本篇，介紹 MySQL 服務(wù)的部署；

二，部署 MySQL 服務(wù)

部署 MySQL

• 可以為指定 node 添加污點，專門用于 mysql 部署（當前只有一個節(jié)點，不考慮）；
• 為了保證mysql容器重啟時數(shù)據(jù)不會丟失：創(chuàng)建 mysql 數(shù)據(jù)目錄，用于存儲 mysql 數(shù)據(jù)，實現(xiàn) MySQL 數(shù)據(jù)的持久化；
• 創(chuàng)建 Secret 對象，向為 mysql 容器提供用戶名、密碼信息；
• 創(chuàng)建 mysql Deployment 配置文件，并創(chuàng)建 deploy 完成 pod 部署；
• 創(chuàng)建 mysql Service 配置文件，并創(chuàng)建 service 解決 ip 漂移問題，對外提供 pod 訪問；
• 為 k8s-master 安裝 mysql，使 k8s-master 能夠使用 mysql 命令，測試數(shù)據(jù)庫使用；

三，MySQL 數(shù)據(jù)的持久化

容器中的數(shù)據(jù)是需要保留的，否則容器重啟就沒了，需要創(chuàng)建數(shù)據(jù)目錄，存儲 MySQL 數(shù)據(jù)；

在本地創(chuàng)建 MySQL 數(shù)據(jù)文件夾，然后掛載到 MySQL 容器，實現(xiàn) MySQL 數(shù)據(jù)的可以持久化

在 k8s-node 節(jié)點創(chuàng)建 MySQL 數(shù)據(jù)文件夾（此文件夾必須為空，否則導(dǎo)致 MySQL 啟動失??；

// 創(chuàng)建數(shù)據(jù)目錄文件夾（mysql 運行時的數(shù)據(jù)目錄，約定好的）
[root@k8s-master ~]# mkdir /var/lib/mysql
[root@k8s-master ~]# ll /var/lib/mysql
總用量 0

創(chuàng)建一個新的文件夾：cicd

將所有的配置文件都放在這個cicd目錄下

[root@k8s-master ~]# mkdir cicd
[root@k8s-master ~]# cd cicd/
[root@k8s-master cicd]# 

四，創(chuàng)建 Secret 對象

通過 Secret 對象，將 MySQL 的用戶名、密碼傳遞到鏡像中使用；

創(chuàng)建 Secret 對象：mysql-auth

// 創(chuàng)建 secret，generic：基于普通文本格式，--from-literal：從字面量創(chuàng)建
[root@k8s-master cicd]# kubectl create secret generic mysql-auth --from-literal=username=root --from-literal=password=123456
secret/mysql-auth created

[root@k8s-master cicd]# kubectl get secret mysql-auth
NAME                  TYPE                                  DATA   AGE
mysql-auth            Opaque                                2      17s

[root@k8s-master cicd]# kubectl get secret mysql-auth -o yaml
apiVersion: v1
data:
  password: MTIzNDU2
  username: cm9vdA==
kind: Secret
metadata:
  creationTimestamp: "2022-01-06T07:14:25Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:data:
        .: {}
        f:password: {}
        f:username: {}
      f:type: {}
    manager: kubectl-create
    operation: Update
    time: "2022-01-06T07:14:25Z"
  name: mysql-auth
  namespace: default
  resourceVersion: "1934676"
  uid: c4a219d2-3754-4133-8484-9b4caa5a54cd
type: Opaque

[root@k8s-master cicd]# echo MTIzNDU2 | base64 -d
123456
[root@k8s-master cicd]# echo cm9vdA== | base64 -d
root

五，創(chuàng)建 Deployment

創(chuàng)建 mysql Deployment 配置文件，并創(chuàng)建 deploy 完成 pod 部署；

創(chuàng)建 deploy：deployment-cicd-mysql.yaml

[root@k8s-master cicd]# vi deployment-cicd-mysql.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: cicd-mysql
spec:
  replicas: 1
  selector:
    matchLabels:
      app: cicd-mysql
  template:
    metadata:
      labels:
        app: cicd-mysql
    spec:
      containers:
      - name: cicd-mysql
        image: mysql:5.7
        imagePullPolicy: IfNotPresent #鏡像拉取策略:如果不存在就拉取鏡像
        args:
        - "--ignore-db-dir=lost+found"
        ports:
        - containerPort: 3306
        volumeMounts: #掛載數(shù)據(jù)卷
        - name: mysql-data
          mountPath: "/var/lib/mysql" #掛載到容器內(nèi)的目錄
        env: #環(huán)境變量
        - name: MYSQL_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysql-auth
              key: password #引用mysql-auth中的password值
      volumes: #數(shù)據(jù)卷
      - name: mysql-data
        hostPath: #宿主機路徑
          path: /var/lib/mysql #宿主機的目錄
          type: Directory 

備注：以下配置文檔中有，但視頻沒用
      tolerations:
      - key: "mysql"
        operator: "Equal"
        value: "true"
        effect: "NoSchedule"

備注：

mysql 自帶 root 用戶，只設(shè)置 root 用戶密碼即可使用；

環(huán)境變量 env MYSQL_ROOT_PASSWORD 是在 mysql:5.7 的鏡像中約定的；

mysql容器啟動成功后，會讀取到 MYSQL_ROOT_PASSWORD 并設(shè)置為密碼；

如：docker run mysql:5.7 --env PASSWORD=123

生效配置

[root@k8s-master cicd]# kubectl apply -f deployment-cicd-mysql.yaml
deployment.apps/cicd-mysql created

[root@k8s-master cicd]# kubectl get pods
NAME                          READY   STATUS             RESTARTS   AGE
cicd-mysql-745975859b-kstnh   0/1     Pending            0          65s
pay-v1-6db6455b8-np2hw        1/1     Running            0          6h38m
user-v1-9f4d589cc-rdmnz       1/1     Running            0          24h
v4-57b4cf7fd9-zcl45           0/1     ImagePullBackOff   0          7d
v4-fb4cd75f5-bf2pf            0/1     ImagePullBackOff   0          2d17h

清理一下資源，刪除 pay-v1、user-v1、v4 的 deploy

[root@k8s-master cicd]# kubectl delete deploy pay-v1 user-v1 v4
deployment.apps "pay-v1" deleted
deployment.apps "user-v1" deleted
deployment.apps "v4" deleted

[root@k8s-master cicd]# kubectl get pods
NAME                          READY   STATUS    RESTARTS   AGE
cicd-mysql-745975859b-kstnh   0/1     Pending   0          4m8s

cicd-mysql-745975859b-kstnh 這個 pod 是 pending 狀態(tài)

[root@k8s-master cicd]# kubectl describe pods cicd-mysql-745975859b-kstnh
Events:
  Type     Reason            Age                  From               Message
  ----     ------            ----                 ----               -------
  Warning  FailedScheduling  49s (x7 over 4m51s)  default-scheduler  0/2 nodes are available: 1 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate, 1 node(s) had taint {pay-v1: true}, that the pod didn't tolerate.


kubectl logs cicd-mysql-6cbd4f95-g64hh 

這是因為，k8s-node 服務(wù)器之前配置了 pay-v1: true，需要刪除掉污點

// 查看污點
[root@k8s-master cicd]# kubectl describe node k8s-node
Taints:             pay-v1=true:NoSchedule

// 刪除污點
[root@k8s-master cicd]# kubectl taint nodes k8s-node pay-v1-
node/k8s-node untainted

// 再次查看，沒有污點了
[root@k8s-master cicd]# kubectl describe node k8s-node
Taints:             <none>

再看 pod 信息，已經(jīng)在創(chuàng)建中了

[root@k8s-master cicd]# kubectl get pods
NAME                          READY   STATUS              RESTARTS   AGE
cicd-mysql-745975859b-kstnh   0/1     ContainerCreating   0          20m

但是有些問題，再看一下容器描述

[root@k8s-master cicd]# kubectl describe pods cicd-mysql-745975859b-kstnh
Events:
  Type     Reason            Age                    From               Message
  ----     ------            ----                   ----               -------
  Warning  FailedScheduling  6m58s (x20 over 24m)   default-scheduler  0/2 nodes are available: 1 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate, 1 node(s) had taint {pay-v1: true}, that the pod didn't tolerate.
  Normal   Scheduled         6m36s                  default-scheduler  Successfully assigned default/cicd-mysql-745975859b-kstnh to k8s-node
  Warning  FailedMount       2m15s (x2 over 4m33s)  kubelet            Unable to attach or mount volumes: unmounted volumes=[mysql-data], unattached volumes=[mysql-data default-token-q4qxd]: timed out waiting for the condition
  Warning  FailedMount       24s (x11 over 6m35s)   kubelet            MountVolume.SetUp failed for volume "mysql-data" : hostPath type check failed: /var/lib/mysql is not a directory

原因是，pod 在 k8s-node 服務(wù)器上部署，但 k8s-node 服務(wù)器上并沒有/var/lib/mysql目錄

所以，需要在 k8s-node 服務(wù)器上創(chuàng)建/var/lib/mysql目錄

[root@k8s-node ~]# mkdir /var/lib/mysql

刪除 pod，再看新啟動的 pod，已經(jīng)正常 Running

（注意：1，不刪除 pod 過一會兒也會正常 Running；2，刪除 pod后，副本會重新創(chuàng)建）

[root@k8s-master deployment]# kubectl delete pod cicd-mysql-745975859b-kstnh
pod "cicd-mysql-745975859b-kstnh" deleted

[root@k8s-master deployment]# kubectl get pods
NAME                          READY   STATUS    RESTARTS   AGE
cicd-mysql-745975859b-gpwzh   1/1     Running   0          10s

[root@k8s-master deployment]# kubectl describe pods cicd-mysql-745975859b-gpwzh
Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  29s   default-scheduler  Successfully assigned default/cicd-mysql-745975859b-gpwzh to k8s-node
  Normal  Pulled     25s   kubelet            Container image "mysql:5.7" already present on machine
  Normal  Created    25s   kubelet            Created container cicd-mysql
  Normal  Started    25s   kubelet            Started container cicd-mysql

查看日志：

[root@k8s-master deployment]# kubectl logs cicd-mysql-745975859b-gpwzh

2022-01-07T01:39:13.425378Z 0 [Note] mysqld: ready for connections.
Version: '5.7.36'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server (GPL)

mysql 已經(jīng)啟動成功，等待連接

六，k8s-master 安裝 mysql 命令

為 k8s-master 安裝 mysql，使 k8s-master 能夠使用 mysql 命令，測試數(shù)據(jù)庫使用；

由于 k8s-maste 沒有安裝 mysql 所以不能使用 mysql 命令

1，k8s-maste 安裝 mysql

2，可以進入容器中操作

[root@k8s-master deployment]# kubectl exec -it cicd-mysql-745975859b-gpwzh -- bash
root@cicd-mysql-745975859b-gpwzh:/# mysql -uroot -p123456
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 4
Server version: 5.7.36 MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

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 (0.01 sec)

mysql> show tables;
+----------------+
| Tables_in_cicd |
+----------------+
| users          |
+----------------+
1 row in set (0.00 sec)

mysql> select * from users;
Empty set (0.00 sec)

\

創(chuàng)建 cicd 數(shù)據(jù)庫，創(chuàng)建表

mysql> create database cicd;
Query OK, 1 row affected (0.04 sec)

mysql> use cicd;
Database changed
mysql> CREATE TABLE `users` (
    ->   `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'ID',
    ->   `name` varchar(255) NOT NULL COMMENT '',
    ->   `age` int(11) NOT NULL COMMENT '',
    ->   `sex` varchar(255) NOT NULL COMMENT '1 2',
    ->   PRIMARY KEY (`id`)
    -> ) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.03 sec)

退出 mysql，退出pod，回到 k8s-master

mysql> exit;
Bye

root@cicd-mysql-745975859b-gpwzh:/# exit
exit

給 k8s-master 安裝 mysql：

// 下載MySQL源安裝包
wget http://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm

// 安裝MySQL源
yum -y install mysql57-community-release-el7-11.noarch.rpm

// 安裝 mysql
yum install mysql-community-server -y

k8s-master 訪問 MySQL

[root@k8s-master ~]# cat /etc/hosts
::1	localhost	localhost.localdomain	localhost6	localhost6.localdomain6
127.0.0.1	localhost	localhost.localdomain	localhost4	localhost4.localdomain4

172.17.178.106	k8s-node
172.17.178.105	k8s-master

[root@k8s-master cicd]# mysql -h172.17.178.105 -P3306 -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 2003 (HY000): Can't connect to MySQL server on '172.17.178.105' (111)

還不能訪問，因為沒有服務(wù)

七，創(chuàng)建 Service

由于 pod 的 ip 是會漂移的， 需要通過 Service 訪問 pod，需要創(chuàng)建服務(wù)

創(chuàng)建 service：service-cicd-mysql.yaml

[root@k8s-master cicd]# vi service-cicd-mysql.yaml

apiVersion: v1
kind: Service
metadata: #源數(shù)據(jù)
  name: service-cicd-mysql
spec: #規(guī)格
  selector: #選擇器
    app: cicd-mysql #與deployment配置中的container-name相對應(yīng)
  ports: #將pod的 3306端口代理到宿主機的3306端口
  - protocol: TCP
    port: 3306
    targetPort: 3306 #虛擬端口->真正的端口要看Service啟動后實際分配的
    
  type: NodePort #不寫就不能訪問到pod

生效配置，服務(wù)啟動

[root@k8s-master cicd]# kubectl apply -f service-cicd-mysql.yaml
service/service-cicd-mysql created

[root@k8s-master cicd]# kubectl get service
NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes           ClusterIP   10.96.0.1       <none>        443/TCP          16d
service-cicd-mysql   NodePort    10.108.224.96   <none>        3306:30509/TCP   11s
service-pay-v1       NodePort    10.97.250.199   <none>        80:30114/TCP     2d19h
service-user-v1      NodePort    10.104.13.40    <none>        80:31071/TCP     14d

3306:30509 服務(wù)的內(nèi)部端口/外部端口（外部訪問 Service 中的 mysql 服務(wù)使用的端口號）

數(shù)據(jù)庫端口：訪問 Service 的 30509 端口

[root@k8s-master cicd]# mysql -h172.17.178.105 -P30509 -uroot -p123456
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 7
Server version: 5.7.36 MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

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> use cicd;
Database changed

mysql> show tables;
+----------------+
| Tables_in_cicd |
+----------------+
| users          |
+----------------+
1 row in set (0.00 sec)

mysql> exit;
Bye

數(shù)據(jù)庫配置完成；

八，結(jié)尾

本篇，完成了 mysql 服務(wù)的創(chuàng)建和測試；

下一篇，介紹后端服務(wù)的部署；文章來源地址http://www.zghlxwxcb.cn/news/detail-773966.html

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