目的

在实际开发过程中，由于网络原因，更新ubuntu设备中的软件时常发生下载速度过缓问题。

修改DNS和软件源可有效解决此类问题。

修改DNS

第一步：重新链接配置文件

调整/etc/resolv.conf的软链接，使其指向件/run/systemd/resolve/resolv.conf

rm /etc/resolv.conf
ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf

第二步：修改配置文件

修改配置文件/etc/systemd/resolved.conf，添加新的DNS服务器IP

[Resolve]
DNS=119.29.29.29 223.5.5.5 223.6.6.6

第三步：使能配置

重启域名解析服务

systemctl restart systemd-resolved
systemctl enable systemd-resolved

第四步：查看新配置

使用 cat /etc/resolv.conf 查看新的/etc/resolv.conf配置

nameserver 119.29.29.29
nameserver 223.5.5.5
nameserver 223.6.6.6
# Too many DNS servers configured, the following entries may be ignored.
nameserver 113.214.230.25
nameserver 113.215.2.222

也可使用命令systemd-resolve --status查询

Global
         DNS Servers: 119.29.29.29
                      223.5.5.5
                      223.6.6.6
...
...
...

修改软件源（以阿里云为例）

#修改配置文件
sudo vi /etc/apt/sources.list

#修改软件源为阿里源
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

#更新固件
sudo apt update
sudo apt upgrade

问题分析

ModuleNotFoundError: No module named ‘netifaces’

执行netplan 命令报错：

# netplan apply
Traceback (most recent call last):
File "/usr/sbin/netplan", line 20, in <module>
from netplan import Netplan
File "/usr/share/netplan/netplan/__init__.py", line 18, in <module>
from netplan.cli.core import Netplan
File "/usr/share/netplan/netplan/cli/core.py", line 24, in <module>
import netplan.cli.utils as utils
File "/usr/share/netplan/netplan/cli/utils.py", line 25, in <module>
import netifaces
ModuleNotFoundError: No module named 'netifaces'

解决方法：修改python版本

rm /usr/bin/python3
ln -sf /usr/bin/python3.6 /usr/bin/python3

Ubuntu设置DNS服务器的IP地址及DNS域名及修改软件源

目的