system: Add 'create-home-directory?' field to <user-account>.

* gnu/system/shadow.scm (<user-account>)[create-home-directory?]: New
field.
(user-account->gexp): Serialize it.
* gnu/build/activation.scm (activate-users+groups)[activate-user]:
Update 'match-lambda' pattern accordingly.  Pass #:create-home? to
'ensure-user'.
(add-user, modify-user, ensure-user): Add #:create-home? parameter and
honor it.
* doc/guix.texi (User Accounts): Document it.

3 files changed, 17 insertions, 5 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 533023854b..e25cf58a31 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -7223,6 +7223,10 @@ A comment about the account, such as the account owner's full name.
 @item @code{home-directory}
 This is the name of the home directory for the account.
 
+@item @code{create-home-directory?} (default: @code{#t})
+Indicates whether the home directory of this account should be created
+if it does not exist yet.
+
 @item @code{shell} (default: Bash)
 This is a G-expression denoting the file name of a program to be used as
 the shell (@pxref{G-Expressions}).
diff --git a/gnu/build/activation.scm b/gnu/build/activation.scm
index 6666cb4856..10aa58d85c 100644
--- a/gnu/build/activation.scm
+++ b/gnu/build/activation.scm
@@ -110,7 +110,8 @@ owner-writable in HOME."
               files)))
 
 (define* (add-user name group
-                   #:key uid comment home shell password system?
+                   #:key uid comment home create-home?
+                   shell password system?
                    (supplementary-groups '())
                    (log-port (current-error-port)))
   "Create an account for user NAME part of GROUP, with the specified
@@ -139,7 +140,7 @@ properties.  Return #t on success."
                           `("-G" ,(string-join supplementary-groups ","))
                           '())
                     ,@(if comment `("-c" ,comment) '())
-                    ,@(if home
+                    ,@(if (and home create-home?)
                           (if (file-exists? home)
                               `("-d" ,home)     ; avoid warning from 'useradd'
                               `("-d" ,home "--create-home"))
@@ -158,7 +159,8 @@ properties.  Return #t on success."
                #t)))))
 
 (define* (modify-user name group
-                      #:key uid comment home shell password system?
+                      #:key uid comment home create-home?
+                      shell password system?
                       (supplementary-groups '())
                       (log-port (current-error-port)))
   "Modify user account NAME to have all the given settings."
@@ -186,7 +188,8 @@ logged in."
   (zero? (system* "groupdel" name)))
 
 (define* (ensure-user name group
-                      #:key uid comment home shell password system?
+                      #:key uid comment home create-home?
+                      shell password system?
                       (supplementary-groups '())
                       (log-port (current-error-port))
                       #:rest rest)
@@ -207,7 +210,8 @@ numeric gid or #f."
 
   (define activate-user
     (match-lambda
-     ((name uid group supplementary-groups comment home shell password system?)
+     ((name uid group supplementary-groups comment home create-home?
+       shell password system?)
       (let ((profile-dir (string-append "/var/guix/profiles/per-user/"
                                         name)))
         (ensure-user name group
@@ -216,6 +220,7 @@ numeric gid or #f."
                      #:supplementary-groups supplementary-groups
                      #:comment comment
                      #:home home
+                     #:create-home? create-home?
                      #:shell shell
                      #:password password)
 
diff --git a/gnu/system/shadow.scm b/gnu/system/shadow.scm
index c3948900eb..6a4063529c 100644
--- a/gnu/system/shadow.scm
+++ b/gnu/system/shadow.scm
@@ -78,6 +78,8 @@
                         (default '()))            ; list of strings
   (comment        user-account-comment (default ""))
   (home-directory user-account-home-directory)
+  (create-home-directory? user-account-create-home-directory? ;Boolean
+                          (default #t))
   (shell          user-account-shell              ; gexp
                   (default #~(string-append #$bash "/bin/bash")))
   (system?        user-account-system?            ; Boolean
@@ -255,6 +257,7 @@ of user '~a' is undeclared")
       #$(user-account-supplementary-groups account)
       #$(user-account-comment account)
       #$(user-account-home-directory account)
+      #$(user-account-create-home-directory? account)
       ,#$(user-account-shell account)             ; this one is a gexp
       #$(user-account-password account)
       #$(user-account-system? account)))