Secure connections with Let's Encrypt certificates are now enabled on all mathr.co.uk domains. A small side-effect you might have noticed is duplicated RSS feed entries, but this was just a one-off. The configuration for the cmcms static site generator that powers this blog is updated, as is the gitweb-aggregator that combines all the feeds from code.mathr.co.uk.
The new HTTPS sites are served by nginx, and the old HTTP served by apache will be turned off at some point, replaced by a redirect in nginx. If you have git repositories cloned from code.mathr.co.uk, it's probably easiest to edit the .git/config with a text editor to replace http with https in the remote section (rather than trying to figure out which git commands would do the same thing).