我們一起聊聊K8s定時備份MySQL并發(fā)送到指定郵箱
一、背景：
一開始的初衷是，想寫一個腳本來監(jiān)控服務(wù)器的高占用率進(jìn)程并通過郵件發(fā)送給我，然后突發(fā)奇想，可以使用這種方式來備份我的數(shù)據(jù)庫，開始動手！
二、設(shè)計思路：
通過編寫Shell腳本，調(diào)用Linux的mail工具，MySQLDump的方式來保存數(shù)據(jù)庫的sql文件，通過Mail工具添加到附件，最后發(fā)送到我的郵箱。
三、編寫啟動腳本
首先我們來編寫一個啟動腳本 為了方便以后的個性化配置，我們將腳本中的變量都提取到一個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接下來我們來寫一下shell腳本，邏輯也很簡單，當(dāng)前時間與啟動時間相同時，則調(diào)用sendmail函數(shù)發(fā)送郵件
#!/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 $CURRENT_TIME
sleep 1
fi
done四、構(gòu)建鏡像
因為我們最后要放到k8s平臺上的，所以我們要構(gòu)建一個鏡像，在構(gòu)建鏡像之前，請先把a(bǔ)pplication.yml demo.sh Dockerfile放在同一目錄下 Dockerfile如下：PS:添加了mysql的客戶端，郵件mail客戶端
FROM centos
RUN mkdir /app && yum install -y mysql.x86_64 sendmail mailx libreport-plugin-mailx
WORKDIR /app
COPY demo.sh .
COPY application.yml .
CMD ["/bin/sh","demo.sh"]使用docker build命令構(gòu)建鏡像,要記得加一下最后的點(diǎn)
docker build -t mysqlmail-bak:1.0.1 .五、添加邊車容器
邊車容器(sidecar)：邊車容器就是與主容器一起在一個pod中運(yùn)行的容器，為業(yè)務(wù)容器賦能，共享一個網(wǎng)絡(luò)空間，所以可以用127.0.0.1:3306連接主容器的數(shù)據(jù)庫。
5.1 創(chuàng)建配置文件
為了方便調(diào)試，我把里面的shell腳本也掛載出來。創(chuàng)建兩個configmap，分別對應(yīng)容器內(nèi)的配置文件與shell腳本，后面如果不需要調(diào)試可以取消mysqlshell的掛載。
apiVersion: v1
kind: ConfigMap
metadata:
name: mysqlmail-conf
namespace: dean
data:
application.yml: |
RUNTIME: 105800
HOST: 127.0.0.1
USER: root
PASSWORD: 123456
DATABASE: dean
TARGETMAIL: deanmr@qq.com
---
apiVersion: v1
kind: ConfigMap
metadata:
name: mysqlmail-shell
namespace: dean
data:
demo.sh: |
#!/bin/bash
RUNTIME=$(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
done5.2 創(chuàng)建有狀態(tài)服務(wù)部署文件
我們的deploy文件使用的是上篇文章中創(chuàng)建的mysql有狀態(tài)服務(wù)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、測試
我們上面給他定的時間是RUNTIME: 105800，上海時區(qū)也就是18點(diǎn)58分，我們來看一下效果 查看日志， 注意：當(dāng)一個pod包含多個容器時，要使用 -c 參數(shù)指定查看哪個容器
[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從日志可以看到，郵件已經(jīng)發(fā)送成功了！我們來去郵箱看一下，發(fā)現(xiàn)也已經(jīng)成功了，至此我們的實(shí)驗完美完成！
