How to use proxy to do PIP/YUM/DNF installation.

pip_proxy_install.sh

# Refer to https://stackoverflow.com/questions/48343669/how-to-install-python-packages-over-ssh-port-forwarding.

# Login to server via following ssh command. Your computer must have permission to connect to PIP server directly.
ssh -R 9999 username@server.host.name

# After login to your server.host.name. Use following command to install proxy package.
pip install package_name --proxy socks5h:127.0.0.1:9999

# The apt and yum can work with this tunnel by setting proxy.
# Add following line in /etc/yum.conf
proxy=socks5h://127.0.0.1:9999

# If you encounter error like "Cannot prepare internal mirrorlist: No URLs in mirrorlist",
# you may need to update your mirror list of YUM and DNF to newer information.
# Use following command to do this.
cd /etc/yum.repos.d/
sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*