一、背景:
一开始的初衷是,想写一个脚本来监控服务器的高占用率进程并通过邮件发送给我,然后突发奇想,可以使用这种方式来备份我的数据库,开始动手!
二、设计思路:
通过编写Shell脚本,调用Linux的mail工具,MySQLDump的方式来保存数据库的sql文件,通过Mail工具添加到附件,最后发送到我的邮箱。
三、编写启动脚本
首先我们来编写一个启动脚本 为了方便以后的个性化配置,我们将脚本中的变量都提取到一个application.yml文件中,文件如下:
RUNTIME: 084900
HOST: 172.16.1.2
USER: root
PORT: 3306
PASSWORD: 123456
DATABASE: dean
TARGETMAIL: deanmr@qq.com
接下来我们来写一下shell脚本,逻辑也很简单,当前时间与启动时间相同时,则调用sendmail函数发送邮件
#!/bin/bash
RUNTIME=$(cat ./application.yml | grep RUNTIME| awk '{print $2}')
HOST=$(cat ./application.yml | grep HOST| awk '{print $2}')
USER=$(cat ./application.yml | grep USER| awk '{print $2}')
PORT=$(cat ./application.yml | grep PORT| awk '{print $2}')
PASSWORD=$(cat ./application.yml | grep PASSWORD| awk '{print $2}')
DATABASE=$(cat ./application.yml | grep DATABASE| awk '{print $2}')
TARGETMAIL=$(cat ./application.yml | grep TARGETMAIL| awk '{print $2}')
function sendmail(){
echo -e "mysqlbak_$CURRENT_TIME" |mail -s "mysqlbak_$CURRENT_TIME" -a $DATABASE.sql $TARGETMAIL
sleep 1
}
while true
do
CURRENT_TIME=$(date +%H%M%S)
if [ $CURRENT_TIME = $RUNTIME ];then
echo "starting bak mysql database"
sendmail
continue
else
echo $CURRENT_TIME
sleep 1
fi
done
四、构建镜像
因为我们最后要放到k8s平台上的,所以我们要构建一个镜像,在构建镜像之前,请先把application.yml demo.sh Dockerfile放在同一目录下 Dockerfile如下:PS:添加了mysql的客户端,邮件mail客户端
FROM centos
RUN mkdir /app && yum install -y mysql.x86_64 sendmail mailx libreport-plugin-mailx
WORKDIR /app
COPY demo.sh .
COPY application.yml .
CMD ["/bin/sh","demo.sh"]
使用docker build命令构建镜像,要记得加一下最后的点
docker build -t mysqlmail-bak:1.0.1 .
五、添加边车容器
边车容器(sidecar):边车容器就是与主容器一起在一个pod中运行的容器,为业务容器赋能,共享一个网络空间,所以可以用127.0.0.1:3306连接主容器的数据库。
5.1 创建配置文件
为了方便调试,我把里面的shell脚本也挂载出来。创建两个configmap,分别对应容器内的配置文件与shell脚本,后面如果不需要调试可以取消mysqlshell的挂载。
apiVersion: v1
kind: ConfigMap
metadata:
name: mysqlmail-conf
namespace: dean
data:
application.yml: |
RUNTIME: 105800
HOST: 127.0.0.1
USER: root
PASSWORD: 123456
DATABASE: dean
TARGETMAIL: deanmr@qq.com
---
apiVersion: v1
kind: ConfigMap
metadata:
name: mysqlmail-shell
namespace: dean
data:
demo.sh: |
#!/bin/bash
RUNTIME=$(cat ./application.yml | grep RUNTIME| awk '{print $2}')
HOST=$(cat ./application.yml | grep HOST| awk '{print $2}')
USER=$(cat ./application.yml | grep USER| awk '{print $2}')
PASSWORD=$(cat ./application.yml | grep PASSWORD| awk '{print $2}')
DATABASE=$(cat ./application.yml | grep DATABASE| awk '{print $2}')
TARGETMAIL=$(cat ./application.yml | grep TARGETMAIL| awk '{print $2}')
function sendmail(){
mysqldump -h$HOST -u$USER -p$PASSWORD --complete-insert --skip-add-drop-table --column-statistics=0 --hex-blob $DATABASE > $DATABASE.sql
echo -e "mysqlbak_$CURRENT_TIME" |mail -s "mysqlbak_$CURRENT_TIME" -a $DATABASE.sql $TARGETMAIL
sleep 1
}
while true
do
CURRENT_TIME=$(date +%H%M%S)
if [ $CURRENT_TIME = $RUNTIME ];then
echo "starting bak mysql database"
sendmail
continue
else
echo $CURRENT_TIME
sleep 1
fi
done
5.2 创建有状态服务部署文件
我们的deploy文件使用的是上篇文章中创建的mysql有状态服务的yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mysql
namespace: dean
spec:
serviceName: mysql-service
selector:
matchLabels:
app: mysql
replicas: 1
template:
metadata:
labels:
app: mysql
spec:
containers:
- name: mysqlmail-bak
imagePullPolicy: IfNotPresent
image: mysqlmail-bak:1.0.1
volumeMounts:
- name: mysqlmail-conf
mountPath: /app/application.yml
subPath: application.yml
- name: mysqlmail-shell
mountPath: /app/demo.sh
subPath: demo.sh
- name: mysql-pod
imagePullPolicy: IfNotPresent
image: mysql:5.7
env:
- name: MYSQL_ROOT_PASSWORD
value: "123456"
ports:
- containerPort: 3306
name: msyql-listin
volumeMounts:
- name: mysql-data
mountPath: /var/lib/mysql
subPath: mysql-data
- name: mysql-conf
mountPath: /etc/mysql/conf.d/my.cnf
subPath: my.cnf
volumes:
- name: mysql-data
hostPath:
path: /data/mysql
- name: mysql-conf
configMap:
name: mysql-conf
- name: mysqlmail-conf
configMap:
name: mysqlmail-conf
- name: mysqlmail-shell
configMap:
name: mysqlmail-shell
---
apiVersion: v1
kind: Service
metadata:
name: mysql-service
namespace: dean
labels:
app: mysql
spec:
ports:
- targetPort: 3306
port: 3306
clusterIP: None
selector:
app: mysql
六、测试
我们上面给他定的时间是RUNTIME: 105800,上海时区也就是18点58分,我们来看一下效果 查看日志, 注意:当一个pod包含多个容器时,要使用 -c 参数指定查看哪个容器
[root@VM-24-15-centos solo]# kubectl logs -n solo mysql-0 -c mysqlmail-bak | grep mysql -C 5
105755
105756
105757
105758
105759
starting bak mysql database
mysqldump: [Warning] Using a password on the command line interface can be insecure.
105801
105802
从日志可以看到,邮件已经发送成功了!我们来去邮箱看一下,发现也已经成功了,至此我们的实验完美完成!