website: Add support for Haunt.

This provides a simple way to build the website locally.

* website/haunt.scm: New file.
* website/README: Document the new build process.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

website/README

@@ -15,10 +15,13 @@ website]] which is implemented in [[https://www.gnu.org/software/guile][Guile]]
 
 * Building
 
-In this implementation, links assume =/software/guix= is the root directory of
-the website.  In order to build the website on your machine, you will want to
-modify the values of ‘(current-url-root)’ and ‘(gnu.org-root)’ parameter
-objects.
+Building the website depends on the static site generator:
+
+  - [[http://haunt.dthompson.us/][Haunt]]
+
+To build the site, run ‘haunt build’ to compile all of the HTML pages.
+To view the results, run ‘haunt serve’ and visit <http://localhost:8080>
+in a web browser.
 
 * Copying
 

website/haunt.scm

@@ -0,0 +1,60 @@
+;;; GuixSD website --- GNU's advanced distro website
+;;; Copyright © 2015 Mathieu Lirzin <mthl@gnu.org>
+;;; Copyright © 2016 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GuixSD website.
+;;;
+;;; GuixSD website 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.
+;;;
+;;; GuixSD website 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 GuixSD website.  If not, see <http://www.gnu.org/licenses/>.
+
+;; This is a build file for Haunt.
+
+(use-modules (haunt site)
+             (haunt reader)
+             (haunt page)
+             (haunt html)
+             (haunt utils)
+             (haunt builder assets)
+             (ice-9 match)
+             (www)
+             (www utils))
+
+(define %local-test?
+  ;; True when we're testing locally, as opposed to producing things to
+  ;; install to gnu.org.
+  (or (getenv "GUIX_WEB_SITE_LOCAL")
+      (member "serve" (command-line))))           ;'haunt serve' command
+
+(when %local-test?
+  ;; The URLs produced in these pages are only meant for local consumption.
+  (format #t "~%Producing Web pages for local tests *only*!~%~%"))
+
+(site #:title "GNU's advanced distro and transactional package manager"
+      #:domain "//www.gnu.org/software/guix"
+      #:default-metadata
+      '((author . "GuixSD Contributors")
+        (email  . "guix-devel@gnu.org"))
+      #:readers (list sxml-reader)
+      #:builders
+      `(,@(map (match-lambda
+                 ((file-name contents)
+                  (lambda (site posts)
+                    (parameterize ((current-url-root (if %local-test?
+                                                         ""
+                                                         (current-url-root)))
+                                   (gnu.org-root (if %local-test?
+                                                     "https://www.gnu.org"
+                                                     (gnu.org-root))))
+                      (make-page file-name (contents) sxml->html)))))
+               %web-pages)
+        ,(static-directory "static")))