It is good practice to run your go web server in a non-root environment. However, if your web server isn’t root then it can’t bind to port 80. One solution is to use nginx as a proxy to listen on ports 80 and 443 for http/https traffic and forward them to your go server running on a higher port such has 8000, 8080 or 9000.   Digital Ocean has a good tutorial on how to install Nginx.

If your WordPress server works normal for a few days and then shows the error message “Error Establishing a Database Connection” it is most likely due to heavy load to your website that your server could not handle. The extra load could be due to a lot of traffic from an incoming link or it could be a malicious actor attempting to brute force their way into your WordPress installation. If you have control of the server such as on AWS or Digital Ocean you can ssh into the server and restart the machine.