HTTPS connections are an easy and secure way to transfer data. Especially if the server can be contacted from the internet, a HTTPS connection should be used.

You can request a certificate from the Let’s Encrypt certificate authority for a server that can be reached from the internet and that are listing on port 80 only. The certificate will expire after 90 days. Currently it is not possible to renew the certificate automatically.

You can add any number of domains (FQDN) that belong to this server and be accessible from letsencrypt.org. e.g.

reporting.sample.com
myapp.sample.com
www.sample.com

You have to agree the subscriber agreement before you can request the certificate.