Re: [gentoo-dev] GLEP81 and /home

[Michael Orlitzky]

On 1/19/20 2:02 PM, Rich Freeman wrote:
>
>> If you're sharing /home, you also have to be sharing user accounts,
>> unless you want everyone to be assigned a random set of files.
>
> I imagine that most people setting up something like this would only
> be sharing high-value UIDs (>1000 in our case).  There is no need for
> postfix on your Gentoo box and postfix on your Debian box to have the
> same UID.  You wouldn't be sshing from postfix on the one to postfix
> on the other and expecting to have the same home directory contents.
>

You can't do that. If you're going to mount files from one system onto
another system, using only an integer <--> username mapping as your
access control mechanism, then you'd better be damn sure that those
integers and usernames match on all systems. Otherwise I might wind up
sharing /home/mjo to rich0 because the "mjo" and "rich0" groups both
have gid 1000 locally.


> Since it is a local account, not in /home, then it would be a separate
> user even if the UID is the same (or otherwise).  You'd set up amavis
> on each mail server.  They might be running different distros.  They
> would be using local users.
>
> Don't get me wrong, it would be cleaner if POSIX users had a scope the
> way that an OS like Windows does it, but it isn't a big deal if you
> use high-numbered UIDs for shared users, and low-numbered UIDs for
> local users.

It's a huge deal. Random users/groups can access your files if the
databases don't agree. The local/remote user distinction does not exist.


>> Everything is fine here, this all works and has worked for 20 years.
>
> Sure, it works fine if you have a single host, or do nothing to share
> your home directories, which I imagine is what 95% of Gentoo users do.
> I doubt most Gentoo users even encrypt /home, even though this has
> been standard for most of those 20 years on just about every major
> distro out there.
>
> If a user wants to put this stuff in /home we should certainly support
> that, and it would work fine if the user sets up the account properly
> before installing the package.  They might get a QA warning, but that
> is the user's concern.

We've talked this to death. Barring any new evidence, /home still seems
like the best place for these, and I don't want to put them in the wrong
spot (forcing users to migrate) just to appease a QA warning from before
GLEP81 was a thing.