How can I configure a Linode as a proxy?

Linode VPN Guides

You can follow the docs linked below for instructions on configuring a Linode VPN.

• ShadowSocks on Ubuntu and CentOS7
• WireGuard

If you are attempting to bypass the Great Firewall of China (GFW), you may want to consider some other basic VPN and proxy connections as well.
In some cases, some of the basic services are still actively filtered by the GFW. In this case, you may want to consider working with some of the specialized services configured to specifically address the difficulties of the GFW. For your convenience, I've laid out multiple VPN/Proxies below.

Basic Services:

Shadowsocks -

https://github.com/shadowsocks
http://shadowsocks.org/en/index.html

OpenVPN with SSH tunneling -

https://openvpn.net/index.php/access-server/docs/quick-start-guide.html
https://redfern.me/tunneling-openvpn-through-ssh/
https://www.vpnanswers.com/openvpn-over-ssh-tunnelling-tutorial-step-by-step/ (with PuTTY)
http://blog.acmelab.org/2008/07/20/mac-os-x-openvpn-bridge-ssh-tunnel-vpn-goodness/ (with Mac OSX)

Streisand -

https://github.com/StreisandEffect/streisand (easy setup of stunnel, tor, shadowsocks, ovpn)

Specialized services:

ShadowsocksR - (shadowsocks with additional obfuscation making it harder to detect.)

https://github.com/shadowsocksrr/shadowsocks-rss
https://github.com/shadowsocksrr
https://plus.google.com/communities/117390969460066916686

Firefly - (A proxy software to help circumventing the Great Firewall.)

https://github.com/yinghuocho/firefly-proxy

Wireguard - (a newer VPN protocol)

https://www.wireguard.com/

Another alternative users have experienced success with, is utilizing their Linode’s IPv6 address. This is located in your Linode’s Remote Access tab. While users have reported connectivity issues with their IPv4 addresses they’ve still been able to access their server via IPv6.