nixpkgs/nixos/modules/programs/shadow.nix
Rickard Nilsson eb2f44c18c Generate /etc/passwd and /etc/group at build time
This is a rather large commit that switches user/group creation from using
useradd/groupadd on activation to just generating the contents of /etc/passwd
and /etc/group, and then on activation merging the generated files with the
files that exist in the system. This makes the user activation process much
cleaner, in my opinion.

The users.extraUsers.<user>.uid and users.extraGroups.<group>.gid must all be
properly defined (if <user>.createUser is true, which it is by default). My
pull request adds a lot of uids/gids to config.ids to solve this problem for
existing nixos services, but there might be configurations that break because
this change. However, this will be discovered during the build.

Option changes introduced by this commit:

* Remove the options <user>.isSystemUser and <user>.isAlias since
they don't make sense when generating /etc/passwd statically.

* Add <group>.members as a complement to <user>.extraGroups.

* Add <user>.passwordFile for setting a user's password from an encrypted
(shadow-style) file.

* Add users.mutableUsers which is true by default. This means you can keep
managing your users as previously, by using useradd/groupadd manually. This is
accomplished by merging the generated passwd/group file with the existing files
in /etc on system activation. The merging of the files is simplistic. It just
looks at the user/group names. If a user/group exists both on the system and
in the generated files, the system entry will be kept un-changed and the
generated entries will be ignored. The merging itself is performed with the
help of vipw/vigr to properly lock the account files during edit.
If mutableUsers is set to false, the generated passwd and group files will not
be merged with the system files on activation. Instead they will simply replace
the system files, and overwrite any changes done on the running system. The
same logic holds for user password, if the <user>.password or
<user>.passwordFile options are used. If mutableUsers is false, password will
simply be replaced on activation. If true, the initial user passwords will be
set according to the configuration, but existing passwords will not be touched.

I have tested this on a couple of different systems and it seems to work fine
so far. If you think this is a good idea, please test it. This way of adding
local users has been discussed in issue #103 (and this commit solves that
issue).
2014-02-05 15:56:51 +01:00

106 lines
2.5 KiB
Nix

# Configuration for the pwdutils suite of tools: passwd, useradd, etc.
{ config, pkgs, ... }:
with pkgs.lib;
let
loginDefs =
''
DEFAULT_HOME yes
SYS_UID_MIN 100
SYS_UID_MAX 499
UID_MIN 1000
UID_MAX 29999
SYS_GID_MIN 100
SYS_GID_MAX 499
GID_MIN 1000
GID_MAX 29999
TTYGROUP tty
TTYPERM 0620
# Ensure privacy for newly created home directories.
UMASK 077
# Uncomment this to allow non-root users to change their account
#information. This should be made configurable.
#CHFN_RESTRICT frwh
'';
in
{
###### interface
options = {
users.defaultUserShell = pkgs.lib.mkOption {
description = ''
This option defines the default shell assigned to user
accounts. This must not be a store path, since the path is
used outside the store (in particular in /etc/passwd).
Rather, it should be the path of a symlink that points to the
actual shell in the Nix store.
'';
type = types.path;
};
};
###### implementation
config = {
environment.systemPackages = [ pkgs.shadow ];
environment.etc =
[ { # /etc/login.defs: global configuration for pwdutils. You
# cannot login without it!
source = pkgs.writeText "login.defs" loginDefs;
target = "login.defs";
}
{ # /etc/default/useradd: configuration for useradd.
source = pkgs.writeText "useradd"
''
GROUP=100
HOME=/home
SHELL=${config.users.defaultUserShell}
'';
target = "default/useradd";
}
];
security.pam.services =
{ chsh = { rootOK = true; };
chfn = { rootOK = true; };
su = { rootOK = true; forwardXAuth = true; };
passwd = {};
# Note: useradd, groupadd etc. aren't setuid root, so it
# doesn't really matter what the PAM config says as long as it
# lets root in.
useradd = { rootOK = true; };
usermod = { rootOK = true; };
userdel = { rootOK = true; };
groupadd = { rootOK = true; };
groupmod = { rootOK = true; };
groupmems = { rootOK = true; };
groupdel = { rootOK = true; };
login = { startSession = true; allowNullPassword = true; showMotd = true; updateWtmp = true; };
chpasswd = { rootOK = true; };
chgpasswd = { rootOK = true; };
};
security.setuidPrograms = [ "passwd" "chfn" "su" "newgrp" ];
};
}