LetsEncrypt SSL for webmin server

Webmin run on port 10000 over HTTPS. By default webmin use self signed SSL certificate. To use SSL for webmin, you need to first get SSL cerificate for the domain you need to use. Refer https://serverok.in/letsencrypt for getting SSL certificate.

Once you have SSL certficate, do following.

cd /etc/webmin
mv miniserv.pem miniserv.pem.old
cat /etc/letsencrypt/live/YOURDOMAIN/cert.pem /etc/letsencrypt/live/YOURDOMAIN/privkey.pem /etc/letsencrypt/live/YOURDOMAIN/chain.pem > /etc/webmin/miniserv.pem

Now restart webmin

systemctl restart webmin

Now you will be able to access webmin using this SSL cert at

https://YOURDOMIN:10000

To auto renew SSL, add following entry to cronjob that renew your LetsEncrypt SSL certificate.

cat /etc/letsencrypt/live/YOURDOMAIN/cert.pem /etc/letsencrypt/live/YOURDOMAIN/privkey.pem /etc/letsencrypt/live/YOURDOMAIN/chain.pem > /etc/webmin/miniserv.pem
systemctl restart webmin