I’ve had these three free videos on my watch list for a while now. In twenty one minutes Chris Fidao runs you through the basic things you’ll want to do whenever you spin up a new VM somewhere.
The videos cover setting up a non-root ssh user, locking down who can log in via SSH and forcing those same people to use SSH keys instead of passwords, using
fail2ban to setup automatic rate limiting of
people bots trying to access your server, and using
iptables to setup firewalls rules that will only allow SSH and HTTP traffic into your servers.
If YouTube’s defacto house style and influencer culture (hey guuuuuuuuuuys) have turned you off of video content you should still check these out. Chris does screencast teaching/learning right.