When it comes to packaging related questions those are really dependent on your distribution of choice.
As for centralized monitoring without any internet connection take a look @Streaming and replication reference | Learn Netdata
The parent netdata node then allows you to store/see charts for children as well. This is not as full featured as netdata cloud but should do.
Parent node can run alarms. You can make children headless (as you noticed already) and make only parent store the data.
- I want to be able to update the packages, so hopefully there is a way to automate the process somewhat. (i.e. bash script that runs git clone, install-netdata.sh, etc).
This again depends on your distribution of choice and/or some admin/management solution used.
Currently netdata itself is “read-only” monitoring solution and does not provide tools for remote administration of your servers.