system: Add (guix build activation).

* gnu/services/dmd.scm (dmd-configuration-file): Remove 'etc'
  parameter.  Move /etc activation code to...
* guix/build/activation.scm: ... here; new file.
* gnu/system.scm (operating-system-boot-script): Augment script: add
  (guix build activation) to the load path; call 'activate-etc'.
* Makefile.am (MODULES): Add guix/build/activation.scm.

1 files changed, 63 insertions, 0 deletions

diff --git a/guix/build/activation.scm b/guix/build/activation.scm
new file mode 100644
index 0000000000..c8491677d3
--- /dev/null
+++ b/guix/build/activation.scm
@@ -0,0 +1,63 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix build activation)
+  #:use-module (ice-9 ftw)
+  #:export (activate-etc))
+
+;;; Commentary:
+;;;
+;;; This module provides "activation" helpers.  Activation is the process that
+;;; consists in setting up system-wide files and directories so that an
+;;; 'operating-system' configuration becomes active.
+;;;
+;;; Code:
+
+(define (activate-etc etc)
+  "Install ETC, a directory in the store, as the source of static files for
+/etc."
+
+  ;; /etc is a mixture of static and dynamic settings.  Here is where we
+  ;; initialize it from the static part.
+
+  (format #t "populating /etc from ~a...~%" etc)
+  (let ((rm-f (lambda (f)
+                (false-if-exception (delete-file f)))))
+    (rm-f "/etc/static")
+    (symlink etc "/etc/static")
+    (for-each (lambda (file)
+                ;; TODO: Handle 'shadow' specially so that changed
+                ;; password aren't lost.
+                (let ((target (string-append "/etc/" file))
+                      (source (string-append "/etc/static/" file)))
+                  (rm-f target)
+                  (symlink source target)))
+              (scandir etc
+                       (lambda (file)
+                         (not (member file '("." ".."))))
+
+                       ;; The default is 'string-locale<?', but we don't have
+                       ;; it when run from the initrd's statically-linked
+                       ;; Guile.
+                       string<?))
+
+    ;; Prevent ETC from being GC'd.
+    (rm-f "/var/guix/gcroots/etc-directory")
+    (symlink etc "/var/guix/gcroots/etc-directory")))
+
+;;; activation.scm ends here