system: Create home directories once 'file-systems' is up.

Fixes <http://bugs.gnu.org/21108>.
Reported by Andy Patterson <ajpatter@uwaterloo.ca>
and Leo Famulari <leo@famulari.name>.

* gnu/build/activation.scm (activate-users+groups)[activate-user]: Pass
  #:create-home? #t iff CREATE-HOME? and SYSTEM?.
(activate-user-home): New procedure.
* gnu/system/shadow.scm (account-shepherd-service): New procedure.
(account-service-type)[extensions]: Add SHEPHERD-ROOT-SERVICE-TYPE
extension.
* gnu/tests/base.scm (run-basic-test)["home"]
["skeletons in home directories"]: New tests.
* gnu/tests/install.scm (%separate-home-os, %separate-home-os-source)
(%test-separate-home-os): New variables.

4 files changed, 147 insertions, 3 deletions

diff --git a/gnu/build/activation.scm b/gnu/build/activation.scm
index 1b31dc1538..cff176e82a 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, 2015, 2016 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -25,6 +25,7 @@
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
   #:export (activate-users+groups
+            activate-user-home
             activate-etc
             activate-setuid-programs
             activate-/bin/sh
@@ -220,7 +221,7 @@ numeric gid or #f."
                      #:supplementary-groups supplementary-groups
                      #:comment comment
                      #:home home
-                     #:create-home? create-home?
+                     #:create-home? (and create-home? system?)
                      #:shell shell
                      #:password password)
 
@@ -268,6 +269,20 @@ numeric gid or #f."
                                (((names . _) ...)
                                 names)))))
 
+(define (activate-user-home users)
+  "Create and populate the home directory of USERS, a list of tuples, unless
+they already exist."
+  (define ensure-user-home
+    (match-lambda
+      ((name uid group supplementary-groups comment home create-home?
+             shell password system?)
+       (unless (or (not home) (directory-exists? home))
+         (mkdir-p home)
+         (unless system?
+           (copy-account-skeletons home))))))
+
+  (for-each ensure-user-home users))
+
 (define (activate-etc etc)
   "Install ETC, a directory in the store, as the source of static files for
 /etc."
diff --git a/gnu/system/shadow.scm b/gnu/system/shadow.scm
index cfdcf5e136..ee9d55c157 100644
--- a/gnu/system/shadow.scm
+++ b/gnu/system/shadow.scm
@@ -21,9 +21,11 @@
   #:use-module (guix records)
   #:use-module (guix gexp)
   #:use-module (guix store)
+  #:use-module (guix modules)
   #:use-module (guix sets)
   #:use-module (guix ui)
   #:use-module (gnu services)
+  #:use-module (gnu services shepherd)
   #:use-module ((gnu system file-systems)
                 #:select (%tty-gid))
   #:use-module ((gnu packages admin)
@@ -43,6 +45,7 @@
             user-account-supplementary-groups
             user-account-comment
             user-account-home-directory
+            user-account-create-home-directory?
             user-account-shell
             user-account-system?
 
@@ -288,6 +291,35 @@ group."
       (activate-users+groups (list #$@user-specs)
                              (list #$@group-specs))))
 
+(define (account-shepherd-service accounts+groups)
+  "Return a Shepherd service that creates the home directories for the user
+accounts among ACCOUNTS+GROUPS."
+  (define accounts
+    (filter user-account? accounts+groups))
+
+  ;; Create home directories only once 'file-systems' is up.  This makes sure
+  ;; they are created in the right place if /home lives on a separate
+  ;; partition.
+  ;;
+  ;; XXX: We arrange for this service to stop right after it's done its job so
+  ;; that 'guix system reconfigure' knows that it can reload it fearlessly
+  ;; (and thus create new home directories).  The cost of this hack is that
+  ;; there's a small window during which first-time logins could happen before
+  ;; the home directory has been created.
+  (list (shepherd-service
+         (requirement '(file-systems))
+         (provision '(user-homes))
+         (modules '((gnu build activation)))
+         (start (with-imported-modules (source-module-closure
+                                        '((gnu build activation)))
+                  #~(lambda ()
+                      (activate-user-home
+                       (list #$@(map user-account->gexp accounts)))
+                      #f)))                       ;stop
+         (stop #~(const #f))
+         (respawn? #f)
+         (documentation "Create user home directories."))))
+
 (define (shells-file shells)
   "Return a file-like object that builds a shell list for use as /etc/shells
 based on SHELLS.  /etc/shells is used by xterm, polkit, and other programs."
@@ -327,6 +359,8 @@ the /etc/skel directory for those."
                 (extensions
                  (list (service-extension activation-service-type
                                           account-activation)
+                       (service-extension shepherd-root-service-type
+                                          account-shepherd-service)
                        (service-extension etc-service-type
                                           etc-files)))))
 
diff --git a/gnu/tests/base.scm b/gnu/tests/base.scm
index a725ca90f3..756d3df800 100644
--- a/gnu/tests/base.scm
+++ b/gnu/tests/base.scm
@@ -146,6 +146,43 @@ info --version")
                      (pk 'services services)
                      '(root #$@(operating-system-shepherd-service-names os)))))
 
+          (test-assert "homes"
+            (let ((homes
+                   '#$(map user-account-home-directory
+                           (filter user-account-create-home-directory?
+                                   (operating-system-user-accounts os)))))
+              (marionette-eval
+               `(begin
+                  (use-modules (gnu services herd) (srfi srfi-1))
+
+                  ;; Home directories are supposed to exist once 'user-homes'
+                  ;; has been started.
+                  (start-service 'user-homes)
+
+                  (every (lambda (home)
+                           (and (file-exists? home)
+                                (file-is-directory? home)))
+                         ',homes))
+               marionette)))
+
+          (test-assert "skeletons in home directories"
+            (let ((homes
+                   '#$(filter-map (lambda (account)
+                                    (and (user-account-create-home-directory?
+                                          account)
+                                         (not (user-account-system? account))
+                                         (user-account-home-directory account)))
+                                  (operating-system-user-accounts os))))
+              (marionette-eval
+               `(begin
+                  (use-modules (srfi srfi-1) (ice-9 ftw))
+                  (every (lambda (home)
+                           (null? (lset-difference string=?
+                                                   (scandir "/etc/skel/")
+                                                   (scandir home))))
+                         ',homes))
+               marionette)))
+
           (test-equal "login on tty1"
             "root\n"
             (begin
diff --git a/gnu/tests/install.scm b/gnu/tests/install.scm
index 4e8d594054..b104efcfd5 100644
--- a/gnu/tests/install.scm
+++ b/gnu/tests/install.scm
@@ -35,6 +35,7 @@
   #:use-module (guix utils)
   #:export (%test-installed-os
             %test-separate-store-os
+            %test-separate-home-os
             %test-raid-root-os
             %test-encrypted-os
             %test-btrfs-root-os))
@@ -218,7 +219,6 @@ IMAGE, a disk image.  The QEMU VM is has access to MEMORY-SIZE MiB of RAM."
                   "-no-reboot" "-m" #$(number->string memory-size)
                   "-drive" "file=disk.img,if=virtio")))))
 
-
 (define %test-installed-os
   (system-test
    (name "installed-os")
@@ -234,6 +234,64 @@ build (current-guix) and then store a couple of full system images.")
 
 
 ;;;
+;;; Separate /home.
+;;;
+
+(define-os-with-source (%separate-home-os %separate-home-os-source)
+  ;; The OS we want to install.
+  (use-modules (gnu) (gnu tests) (srfi srfi-1))
+
+  (operating-system
+    (host-name "liberigilo")
+    (timezone "Europe/Paris")
+    (locale "en_US.utf8")
+
+    (bootloader (grub-configuration (device "/dev/vdb")))
+    (kernel-arguments '("console=ttyS0"))
+    (file-systems (cons* (file-system
+                           (device "my-root")
+                           (title 'label)
+                           (mount-point "/")
+                           (type "ext4"))
+                         (file-system
+                           (device "none")
+                           (title 'device)
+                           (type "tmpfs")
+                           (mount-point "/home")
+                           (type "tmpfs"))
+                         %base-file-systems))
+    (users (cons* (user-account
+                   (name "alice")
+                   (group "users")
+                   (home-directory "/home/alice"))
+                  (user-account
+                   (name "charlie")
+                   (group "users")
+                   (home-directory "/home/charlie"))
+                  %base-user-accounts))
+    (services (cons (service marionette-service-type
+                             (marionette-configuration
+                              (imported-modules '((gnu services herd)
+                                                  (guix combinators)))))
+                    %base-services))))
+
+(define %test-separate-home-os
+  (system-test
+   (name "separate-home-os")
+   (description
+    "Test basic functionality of an installed OS with a separate /home
+partition.  In particular, home directories must be correctly created (see
+<https://bugs.gnu.org/21108>).")
+   (value
+    (mlet* %store-monad ((image   (run-install %separate-home-os
+                                               %separate-home-os-source
+                                               #:script
+                                               %simple-installation-script))
+                         (command (qemu-command/writable-image image)))
+      (run-basic-test %separate-home-os command "separate-home-os")))))
+
+
+;;;
 ;;; Separate /gnu/store partition.
 ;;;