Ubuntu 20.04 systemd EC2 guest
Build the local guest image before launching ami-0abcdef1234567892:
docker build --platform linux/amd64 -t floci/ami-ubuntu:20.04 docker/ec2/ami-images/ubuntu-20.04
The image runs systemd and starts SSH on every EC2 boot. Enable application services with
systemctl enable --now <service> so they restart after StopInstances and StartInstances.