This is required by (among others) Podman to run containers in rootless mode.
Other distributions such as Fedora and Ubuntu already set up these mappings.
The scheme with a start UID/GID offset starting at 100000 and increasing in 65536 increments is copied from Fedora.
This enlarges the system uid/gid range 6-fold, from 100 to 600 ids. This
is a preventative measure against running out of dynamically allocated
ids for NixOS services with isSystemUser, which should become the
preferred way of allocating uids for non-real users.
We don’t want any trailing whitespace, otherwise we mess up the
formating of the shadow file. Some things like readFile may have the
trailing new line.
Fixes#66745
When a user or group is revived, this allows it to be allocated the
UID/GID it had before.
A consequence is that UIDs and GIDs are no longer reused.
Fixes#24010.
Verified that following nixos configuration:
users.users.foo = {
uid = 1000;
name = "foo";
};
users.users.bar = {
name = "bar";
};
Before this commit both users will get uid of 1000, after it's applied
bar will correctly get 1001.
Instead of showing this output from "nixos-rebuild switch":
warning: not applying GID change of group ‘munin’
warning: not applying UID change of user ‘ntp’
print this:
warning: not applying GID change of group ‘munin’ (95 -> 102)
warning: not applying UID change of user ‘ntp’ (3 -> 179)
This makes it possible for users to take action and fixup the UIDs/GIDs
that NixOS won't touch.
Perl seems to write the file in latin1 independent of the actual input
encoding. This can corrupt the "description" field of /etc/passwd. By
setting "binmode" to ":utf8" Perl can be forced to write UTF-8. Ideally
the program would simply read/write the fields by value without any
changes in encoding. However, assuming/enforcing UTF-8 is a lot better
than using an obsolete coding like latin1.
I.e. don't call "passwd" to update /etc/shadow from the "password"
option. This has the side-effect of not updating the password if
mutableUsers = true (since the code path for "hashedPassword" has a
check for mutableUsers).
Fixes#4747.
With mutableUsers = true, we now ensure that all users and groups that
were created declaratively, are updated or removed
appropriately. Thus, adding a user to users.extraUsers and then
removing it now causes the acoount to be removed from
/etc/passwd. Thus user/group management is fully congruent except that
users and groups that were created imperatively (via useradd/groupadd)
are not touched. We distinguish between declarative and imperative
users/groups by tracking the former in
/var/lib/nixos/declarative-{groups,users}.
With mutableUsers = false, you are now no longer required to specify
UIDs/GIDs for all users. The handling of mutableUsers = true/false is
the same code path; the only difference is that the "false" mode
ignores the existing contents of /etc/{passwd,group}.
The attribute ‘createUser’ is gone. It doesn't really make sense to
specify users that shouldn't be created.
