I’d imagine we might be able to have a script that fetches the RPM files
For the RPMs only, yes that would be just fine to download them, probably directly into the Yum local repo and then run the install. Nothing would even be needed to modify in the playbooks because if a package is present in the cache and Yum does not have a connection, it will probably use the local package (if it is of the right version of course)
This is what this post describes: Installing Bahmni with limited internet
However, not everything is shipped as a RPM. For instance the Oracle Java VM, OpenMRS modules, OpenMRS Core WAR file etc… Those are components that are fetched during installation.
How would you do for those?
Or did you consider creating a Docker container all set up the way you want (see Running Bahmni on Docker) and store the container in a repo accessible offline?