A major hassle for me when setting up lots of docker-based services on a machine is to setup the individual nginx configs to forward the domains to the correct services.
TechOverflow provides a simple way to automatically generate nginx configs for a single domain to configure port forwarding to a specific port.
wget -qO- https://techoverflow.net/scripts/generate-nginx-docker-config.sh | sudo bash /dev/stdin service.mydomain.com 1234
Note: This script was tested on Ubuntu 18.04 and is regularly used by myself and others. However, if used incorrectly or in case there is a major bug, it might damage your webserver configuration, so be sure to be prepared to fix any issues that might arise. This script is provided without any warranty, expressed or implied.
Remember to replace service.mydomain.com by your domain and 1234 by the local port your docker service is listening to.
The script will generate /etc/nginx/sites-enabled/[domain].conf.
Run
sudo nginx -t
to check if the config syntax is OK, and only if that succeeds, run
sudo service nginx reload
Now your domain should be online and I recommend running
sudo certbot --nginx