This post is an open question to the wide range of GNU/Linux site admins out there. Possibly some of you have the joy of maintaining GNU/Linux also on user endpoint devices (i.e. user workstations, user notebooks, etc.), not only on corporate servers.
TL;DR; In the context of a customer project, I am researching ways of mimicking (or inventing anew) a feature well known (and sometimes also well hated) from the MS Windows world: Roaming User Profiles. If anyone does have any input on that, please contact me (OFTC/Freenode IRC, Telegram, email). I am curious what your solution may be.
The Use Case Scenario
In my use case, all user machines shall be mobile (notebooks, convertibles, etc). The machines maybe on-site most of the time, but they need offline capabilities so that the users can transparently move off-site and continue their work. At the same time, a copy of the home directory (or the home directory itself) shall be stored on some backend fileservers (for central backups as well as for providing the possibility to the user to login to another machine and be up-and-running +/- out-of-the-box).
The Vision
Initial Login
Ideally, I'd like to have a low level file system feature for this that handles it all. On corporate user logon (which must take place on-site and uses some LDAP database as backend), the user credentials get cached locally (and get re-mapped and re-cached with every on-site login later on), and the home directory gets mounted from a remote server at first.
Shortly after having logged in everything in the user's home gets sync'ed to a local cache in the background without the user noticing. At the end of the sync a GUI user notification would be nice, e.g. like "All user data has been cached locally, you are good to go and leave off-site now with this machine."
Moving Off-Site
A day later, the user may be travelling or such, the user logs into the machine again, the machine senses being offline or on some alien (not corporate) network, but the user can just continue their work, all in local cache.
Several days later, the same user with the same machine returns back to office, logs into the machine again, and immediately after login, all cached data gets synced back to the user's server filespace.
Possible Conflict Policies
Now there might be cases where the user has been working locally for a while and all the profile data received slight changes. The user might have had the possibility to log into other corporate servers from the alien network he*she is on and with that login, some user profile files probably will have gotten changed.
Regarding client-server sync policies, one could now enforce a client-always-wins policy that leads to changes being dropped server-side once the user's mobile workstation returns back on-site. One could also set up a bi-directional sync policy for normal data files, but a client-always-wins policy for configuration files (.files and .folders). Etc.pp.
Request for Feedback and Comments
I could go on further and further with making up edges and corner cases of all this. We had a little discussion on this some days ago on the #debian-devel IRC channel already. Thanks to all contributors to that discussion.
And again, if you have solved the above riddle on your site and are corporate-wise allowed to share the concept, I'd be happy about your feedback.
Plese get in touch!
light+love
Mike (aka sunweaver on the Fediverse and in Debian)