SpeedTest server in Go.
Download the website files from adolfintel/speedtest.
They also have versions of this server written in PHP and Node.
Use the -web-root option to point to the website files.
To avoid having users hitting the Google Data Saver proxy servers when doing a speed test, use the options -redir-bind and -redir-url to redirect to -web-bind.
To restrict access based on the remote IP address, use the option -allow-from.
Data received on /ping.php is forwarded to -ping-url. Key addr is added, containing the client IP:port. This feature may be used to handle data from the browser, like test results, etc.