vim /etc/profile.d/proxy.sh
vim /etc/dnf/dnf.conf
source /etc/profile

# /etc/profile.d/proxy.sh 

[Service]
Environment="HTTP_PROXY=http://192.168.1.23:7890"
Environment="HTTPS_PROXY=http://192.168.1.23:7890"
Environment="ALL_PROXY=http://192.168.1.23:7890"
Environment="NO_PROXY=localhost,127.0.0.1"

# /etc/dnf/dnf.conf  

# 底部加入
proxy=http://192.168.1.100:7890