Posted on Monday 13th April 2020
Using CertBot we can use letsencrypt to get a wilcard SSL Certificate, but on Debain 8 due to limitations of the system certbot cannot generate wildcard ones via the automated scripts.
Instead you need to request a certificate and perform a manual dns challenge by adding a DNS TXT Record.
Using the following command you request the certificate and trigger the DNS TXT Challenge
certbot-auto certonly --manual --preferred-challenges=dns --email email@example.com https://acme-v02.api.letsencrypt.org/directory --agree-tos -d *.example.co.uk