socat daemon systemd

https://unix.stackexchange.com/questions/125382/migrate-socat-init-script-to-systemd
For socat, I use a pure systemd approach. This is an example for a serial loopback:

[Unit]
Description=Socat Serial Loopback
#Before=my-other.service

[Service]
Type=simple
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=socat-serial-lo

ExecStart=/usr/bin/socat -d -d pty,raw,echo=0,link=/tmp/seriallo-a pty,raw,echo=0,link=/tmp/seriallo-b
Restart=always

[Install]
WantedBy=multi-user.target

This can be written to /etc/systemd/system/socat-serial-lo.service (in Ubuntu 16.04+), and then:

systemctl daemon-reload
systemctl start socat-serial-lo
systemctl enable socat-serial-lo  # (to start it during bootup)

One advantage of this method is that the command line defined by ExecStart can be tested directly from command line without alterations, in order to test the command.
answered Sep 21 at 13:45

The best tool for this that I know of is socat. An example of what you want would look like this:

socat TCP-LISTEN:8010,fork,reuseaddr TCP4::8002

This would listen on port 8010 (on all interfaces) and then forward the traffic to server address on port 8002. Any responses would be forwarded back to the original sender.

Note that the server address should not contain the protocol or path but just the domain or IP address (e.g. www.google.com, NOT http://www.google.com/).

The fork parameter allows multiple connections and the reuseaddr keeps socat from needlessly tying up the address in case it crashes.
https://superuser.com/questions/642666/simple-reverse-proxy

This is really helpful dude!🤗