Would self-hosting a Nextcloud instance locally without an internet connection be viable?
Use case: Around 5 people need to share files over the network, collaborate on Office documents in real-time, use GitLab, and a To-do/Task management tool.
Beyond the initial setup, does any of these requirements need an active Internet connection, or can we all connect to the Raspberry Pi server via Ethernet?
It is possible, but the browsers will complain about unencrypted connections. But you could also set it up as a proper internet facing service with domain name and SSL certificates and have the main router do NAT reflection to avoid all the internal traffic going over the ISP as well.
That’s a bit beyond my expertise, but thanks for answering.
Follow-up question: Would setting it up in a way that it is connected to the internet, but when it gets disconnected, it automatically works over the network?
Reason: My country is going through rough times, and sometimes the internet connection is lost/gets extremely slow. It can last from 10 minutes to a few hours. I want to find a solution to this, so that we can remain productive without disruption (like if the internet went down, everything should remain working automatically without us interfering and losing focus)
It is not very difficult with a router OS like OpenWRT or OPNsense, but I guess it might still try to do DNS queries, not 100% sure. You could probably also run your own local DNS server, but I never tried that.
What you can maybe do is add a second mobile connection as a fallback via Mwan3 if that is a bit more reliable.
But maybe something like Syncthing and desktop apps is in the end more reliable then stuff that is really meant for internet facing services.