Error - Could not bind TCP port 80 because it is already in use by another process on this system (such as a web server)

Let's Encrypt is a terrific new free service that allows users to obtain a free SSL certificate to secure their website. Those free certificates only last a few months and must be updated on a regular basis.

You might be running into this error about not being able to renew Let's Encrypt certificates after issuing this command below.

sudo certbot renew -d your.website.com

OUTPUT:

Failed to renew certificate your.website.com with error:
Could not bind TCP port 80 because it is already in use by
another process on this system (such as a web server). 
Please stop the program in question and then try again.

What we need to do here is stop and start all the web server applications you might have running.
ie. Apache HTTP Server, Nginx, Lighttpd, OpenLiteSpeed... you name it.

$ sudo systemctl stop nginx

$ sudo systemctl restart nginx

then check each for their status;

$ sudo systemctl status nginx

OUTPUT

● nginx.service - A high performance web server and a reverse 
proxy server
     Loaded: loaded (/lib/systemd/system/nginx.service; enabled; 
vendor preset: enabled)
     Active: active (running) since Wed 2023-11-22 16:24:51 UTC;
12s agoDocs: man:nginx(8)
    Process: 1291303 ExecStartPre=/usr/sbin/nginx -t -q -g daemon 
on; master_process on; (code=exited, status=0/SUCCESS)
    Process: 1291316 ExecStart=/usr/sbin/nginx -g daemon on; 
master_process on; (code=exited, status=0/SUCCESS)
   Main PID: 1291318 (nginx)
      Tasks: 7 (limit: 2100)
     Memory: 16.7M
        CPU: 614ms
     CGroup: /system.slice/nginx.service
     .....
     ....
     ..
     .

now run;

$ sudo certbot renew -d your.website.com

OUTPUT

Renewing an existing certificate
IMPORTANT NOTES:
- Congratulations! Your certificate and chain have been saved at:
 .....
 ...
 ..
 .

And voila!