************************      配置dns服務-dnsmasq        ***************************
#安裝dnsmasq 服務
[email protected]:~$ sudo apt-get install dnsmasq
#修改dnsmasq 配置檔案
[email protected]:~$ grep -vE "^$|^#" /etc/dnsmasq.conf
listen-address=172.17.43.1,127.0.0.1,192.168.0.236  #新增監聽地址
#新增需解析的域名
[email protected]
 
:~$ cat /etc/dnsmasq.d/common
address=/alitest.jingning96.com/87.194.23.15
#重啟dnsmasq 服務
[email protected]:~$ sudo service dnsmasq restart
#將dnsmasq 加入開機啟動項
[email protected]:~$ sudo systemctl enable dnsmasq
#檢測配置是否生效
[email protected]:~$ nslookup alitest.jingning96.com
Server:		127.0.0.1
Address:	127.0.0.1#53

Name:	alitest.jingning96.com
Address: 87.194.23.15
#檢視域名解析時間
 
[email protected]:~$ curl -o /dev/null -s -w %{time_connect}:%{time_starttransfer}:%{time_total} alitest.jingning96.com
10.818:11.016:11.156
[email protected]:~$ curl -o /dev/null -s -w %{time_connect}:%{time_starttransfer}:%{time_total} alitest.jingning96.com
0.209:0.407:0.618

*****************************  docker指定dns解析伺服器  **************************
#修改docker配置檔案
 
[email protected]:~$ grep -vE "^$|^#" /etc/default/docker
DOCKER_OPTS="--bip=172.17.43.1/24 --dns=172.17.43.1 --dns=114.114.114.114"

[email protected]:~$ cat /lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target docker.socket firewalld.service
Wants=network-online.target
Requires=docker.socket

#若重啟docker服務後發現配置未生效，則 EnvironmentFile 未設定,未獲取$DOCKER_OPTS 引數，修改如下
[email protected]:~$ cat /lib/systemd/system/docker.service
[Service]
Type=notify
EnvironmentFile = -/etc/default/docker   # 指定配置檔案
ExecStart=/usr/bin/dockerd -H fd:// $DOCKER_OPTS # 指定讀取 $DOCKER_OPTS
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=1048576
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s

[Install]
WantedBy=multi-user.target

#載入docker配置
$ sudo systemctl daemon-reload
#重啟docker 服務
$ sudo service docker restart
#檢測配置是否生效
[email protected]:~$ docker run -it ******** bash
[email protected]:/# cat /etc/resolv.conf
nameserver 172.17.43.1
nameserver 114.114.114.114
[email protected]:/# nslookup alitest.jingning96.com
Name:      alitest.jingning96.com
Address 1: 87.194.23.15 bogon
[email protected]:/# curl -o /dev/null -s -w %{time_connect}:%{time_starttransfer}:%{time_total} alitest.jingning96.com
0.126:0.236:0.301

*** 若線上站點不宜重啟docker服務，則可以在容器啟動時使用--add-host動態新增/etc/hosts檔案中的內容 ***
docker run \
 -d \
 --name=test \
 --add-host='www.jingning96.com:192.168.0.235' \
 ubuntu:latest