What are the requirements for cloud federation to work?
Right now we have some local servers that have (slow and intermittent) internet access but are otherwise used as an LAN intranet of sorts, but I was wondering if they could not be ‘federated’ for some limited exchange of data between the sites.
We could set up one instance on a proper internet host, but the others are just on a regular internet connection with a router firewall and dynamic IP.
Thus I am a bit skeptical if in such a setting the federation system will recognize the ‘local’ servers.
Any ideas how that could work?
Otherwise we are probably just going to use the external storage feature with a google-drive/drop-box as the central exchange or so.
It depends which way around you are using federated shares. If the storage to be shared is on the public server, your local setups only need internet access. If the main storage is in your local setups, the external setup must have a way to connect to these local servers (port forwarding, vpn, …).
Indeed, it can be just used as an external storage like dropbox. Federated sharing also allows users of your cloud to directly share content to users of the other setup. In a large company, you could split up the setups, have a development.yourcompany.com, purchase.yourcompany.com, … and users can share content with each other as if it were on one server. However, this feature requires that there is a decent connection speed between the servers because the content is shared but resides only on the storage of its owner (it will be requested each time from the original server. There is no caching or synching between the servers).