This repository hosts a Dockerfile for easily deploying Omeka S with Docker. The core idea of these images is that they take care only of Omeka S core: you will need to take care of the config files, modules, and themes.
In order to update, you normally just need to change the tag of the relevant image if you're taking this from Docker Hub, or update the relevant line in the Dockerfile if you build this image yourself.
Recent versions are available directly from Docker Hub https://hub.docker.com/r/giocomai/omeka-s-docker
Check out the relevant tags. At this stage, both Omeka S 3.2.3 and Omeka S 4.0.4 are kept reasonably updated.
In this repository, you will find also a "docker-compose_traefik_example.yml". Adjust the lines where you find "FIXME" and, after adjusting relevant details in the database.ini file you should be good to go with a deployed Omeka S.
In your omekas volume, you will have a config folder, and inside it a database.ini file.
Its contents should be something along the lines of:
user = "secretstring"
password = "secretpassword"
dbname = "secretstring"
host = "omekas_db"
(obviously, fix these lines with the values you used in your docker-compose.yml)
If you use this in deployment, you'll probably want to have a look also at the local.config.php file in the same folder.
You will also find a "docker-compose_local_example.yml". Adjust the lines where you find "FIXME", update your database.ini as shown above, and you should be good to go with an instance of Omeka S on your local machine at the 172.20.0.1 address.