ubuntu18 (change the root password, set the root remote login, change the source, set up a static ip (here 18 version))

• Changing the root password

sudo passwd root

• Set the root can remotely log

 The default without ssh, ssh so you need to install it

sudo apt install openssh-server

 Allow root user login, edit sshd_config

sudo vim /etc/ssh/sshd_config
Found under item # Authentication
PermitRootLogin prohibit-password改成PermitRootLogin yes

Get ssh restart

sudo systemctl restart sshd

• Replace domestic sources

Backup

sudo cp /etc/apt/sources.list /etc/apt/sources_init.list

Edit /etc/apt/sources.list to replace Ali source

Ali source
deb http: // mirrors.aliyun.com/ubuntu/ great main 
deb-src http: // mirrors.aliyun.com/ubuntu/ great main 

deb http: // mirrors.aliyun.com/ubuntu/ great-updates main 
deb -SR http: // mirrors.aliyun.com/ubuntu/ great-updates main 

deb http: // mirrors.aliyun.com/ubuntu/ great universe 
deb-src http: // mirrors.aliyun.com/ubuntu/ great universe 
deb http: // mirrors.aliyun.com/ubuntu/ great-updates universe 
deb-src http: // mirrors.aliyun.com/ubuntu/ great-updates universe 

deb http: //mirrors.aliyun.com/ubuntu/ great-security main 
deb-src http: // mirrors.aliyun.com/ubuntu/ great-security main 
deb http: // mirrors.aliyun.com/ubuntu/ great-security universe 
Deb src http: // mirrors.aliyun.com/ubuntu/ great-security universe

Update fixes package

apt-get -f install
apt-get upgrade

 According to the card number edit /etc/netplan/50-cloud-init.yaml set static ip I have here is ens33

network:
    ethernets:
        ens33:
            addresses: [192.168.3.244/24, ]
            dhcp4: no
            dhcp6: no
            gateway4:  192.168.3.1
            nameservers:
                addresses: [8.8.8.8, 9.9.9.9]
    version: 2

 Effective immediately

netplan apply