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authorLudovic Courtès <ludo@gnu.org>2015-04-08 21:23:45 +0200
committerLudovic Courtès <ludo@gnu.org>2015-04-08 21:41:04 +0200
commit9bea87a542d52bcaedfb4febb01bbe94b69934cf (patch)
treeb2ae82d333192193753367399f442c69c2cc40cb
parenta231ef7eec3246ed9e0ed3ec99eba4be334f635a (diff)
downloadguix-9bea87a542d52bcaedfb4febb01bbe94b69934cf.tar
guix-9bea87a542d52bcaedfb4febb01bbe94b69934cf.tar.gz
activation: Remove undeclared user accounts and groups.
Fixes <http://bugs.gnu.org/19795>. Reported by David Thompson <dthompson2@worcester.edu>. * gnu/build/activation.scm (enumerate, current-users, current-groups, delete-user, delete-group): New procedures. (activate-users+groups): Add calls to 'delete-user' and 'delete-group'. * doc/guix.texi (User Accounts): Add a paragraph about statelessness. Explain that passwords are preserved.
-rw-r--r--doc/guix.texi16
-rw-r--r--gnu/build/activation.scm49
2 files changed, 60 insertions, 5 deletions
diff --git a/doc/guix.texi b/doc/guix.texi
index 70604b7603..c0af4cb722 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -4238,7 +4238,9 @@ command, from the same-named package. This relies on the
@node User Accounts
@subsection User Accounts
-User accounts are specified with the @code{user-account} form:
+User accounts and groups are entirely managed through the
+@code{operating-system} declaration. They are specified with the
+@code{user-account} and @code{user-group} forms:
@example
(user-account
@@ -4252,6 +4254,14 @@ User accounts are specified with the @code{user-account} form:
(home-directory "/home/alice"))
@end example
+When booting or upon completion of @command{guix system reconfigure},
+the system ensures that only the user accounts and groups specified in
+the @code{operating-system} declaration exist, and with the specified
+properties. Thus, account or group creations or modifications made by
+directly invoking commands such as @command{useradd} are lost upon
+reconfiguration or reboot. This ensures that the system remains exactly
+as declared.
+
@deftp {Data Type} user-account
Objects of this type represent user accounts. The following members may
be specified:
@@ -4291,7 +4301,9 @@ graphical login managers do not list them.
@item @code{password} (default: @code{#f})
You would normally leave this field to @code{#f}, initialize user
passwords as @code{root} with the @command{passwd} command, and then let
-users change it with @command{passwd}.
+users change it with @command{passwd}. Passwords set with
+@command{passwd} are of course preserved across reboot and
+reconfiguration.
If you @emph{do} want to have a preset password for an account, then
this field must contain the encrypted password, as a string.
diff --git a/gnu/build/activation.scm b/gnu/build/activation.scm
index 909e971833..64c3410baf 100644
--- a/gnu/build/activation.scm
+++ b/gnu/build/activation.scm
@@ -1,5 +1,5 @@
;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
;;;
;;; This file is part of GNU Guix.
@@ -40,6 +40,24 @@
;;;
;;; Code:
+(define (enumerate thunk)
+ "Return the list of values returned by THUNK until it returned #f."
+ (let loop ((entry (thunk))
+ (result '()))
+ (if (not entry)
+ (reverse result)
+ (loop (thunk) (cons entry result)))))
+
+(define (current-users)
+ "Return the passwd entries for all the currently defined user accounts."
+ (setpw)
+ (enumerate getpwent))
+
+(define (current-groups)
+ "Return the group entries for all the currently defined user groups."
+ (setgr)
+ (enumerate getgrent))
+
(define* (add-group name #:key gid password system?
(log-port (current-error-port)))
"Add NAME as a user group, with the given numeric GID if specified."
@@ -128,6 +146,17 @@ properties. Return #t on success."
,name)))
(zero? (apply system* "usermod" args))))
+(define* (delete-user name #:key (log-port (current-error-port)))
+ "Remove user account NAME. Return #t on success. This may fail if NAME is
+logged in."
+ (format log-port "deleting user '~a'...~%" name)
+ (zero? (system* "userdel" name)))
+
+(define* (delete-group name #:key (log-port (current-error-port)))
+ "Remove group NAME. Return #t on success."
+ (format log-port "deleting group '~a'...~%" name)
+ (zero? (system* "groupdel" name)))
+
(define* (ensure-user name group
#:key uid comment home shell password system?
(supplementary-groups '())
@@ -186,8 +215,22 @@ numeric gid or #f."
#:system? system?))))
groups)
- ;; Finally create the other user accounts.
- (for-each activate-user users))
+ ;; Create the other user accounts.
+ (for-each activate-user users)
+
+ ;; Finally, delete extra user accounts and groups.
+ (for-each delete-user
+ (lset-difference string=?
+ (map passwd:name (current-users))
+ (match users
+ (((names . _) ...)
+ names))))
+ (for-each delete-group
+ (lset-difference string=?
+ (map group:name (current-groups))
+ (match groups
+ (((names . _) ...)
+ names)))))
(define (activate-etc etc)
"Install ETC, a directory in the store, as the source of static files for