I agree that ideally the VM server and the DNS would be configured for IPv6, but this isn’t the case with this server and I might not be the only person still running a server using IPv4 so it appears fairly reasonable to me to disable IPv6 in the Nginx config in the Docker container, it is a simply one line solution in containers/app.yml and it does the job for now:
## Any custom commands to run after building
run:
- exec: echo "Beginning of custom commands"
- exec: sed -e 's/listen \[::\]:80;/#listen [::]:80;/' -i /etc/nginx/letsencrypt.conf
As far as I’m concerned this “solution” is good enough for now…