Initial commit

This is a service designed to provide information about Guix. At the
moment, this initial prototype gathers up information about packages,
the associated metadata and derivations.

The initial primary use case is to compare two different revisions of
Guix, detecting which packages are new, no longer present, updated or
otherwise different.

It's based on the Mumi project.

[1]: https://git.elephly.net/software/mumi.git

guix-data-service/config.scm.in

@@ -0,0 +1,35 @@
+;;; Guix Data Service -- Information about Guix over time
+;;; Copyright © 2017, 2018 Ricardo Wurmus <rekado@elephly.net>
+;;; Copyright © 2019 Christopher Baines <mail@cbaines.net>
+;;;
+;;; This program is free software: you can redistribute it and/or
+;;; modify it under the terms of the GNU Affero General Public License
+;;; as published by the Free Software Foundation, either version 3 of
+;;; the License, or (at your option) any later version.
+;;;
+;;; This program 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
+;;; Affero General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU Affero General Public
+;;; License along with this program.  If not, see
+;;; <http://www.gnu.org/licenses/>.
+
+(define-module (guix-data-service config)
+  #:export (%config))
+
+(define %config
+  (let ((config
+         ;; Try to find the "assets" directory relative to the executable
+         ;; first.  This is useful when using "pre-inst-env".
+         `((assets-dir  . ,(let ((maybe-dir
+                                  (string-append (getcwd) "/assets")))
+                             (if (file-exists? maybe-dir)
+                                 maybe-dir
+                                 ;; TODO: use @assetsdir@ variable here
+                                 "@prefix@/share/guix-data-service/assets")))
+           (host        . "localhost")
+           (port        . 8765))))
+    (lambda (key)
+      (assoc-ref config key))))