;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017 Sou Bunnbu <iyzsong@member.fsf.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 (gnu services sysctl)
  #:use-module (gnu services)
  #:use-module (gnu services shepherd)
  #:use-module (gnu packages linux)
  #:use-module (guix gexp)
  #:use-module (guix records)
  #:use-module (srfi srfi-1)
  #:use-module (ice-9 match)
  #:export (sysctl-configuration
            sysctl-service-type))


;;;
;;; System Control Service.
;;;

(define-record-type* <sysctl-configuration>
  sysctl-configuration make-sysctl-configuration
  sysctl-configuration?
  (sysctl   sysctl-configuration-sysctl    ; path of the 'sysctl' command
            (default (file-append procps "/sbin/sysctl")))
  (settings sysctl-configuration-settings  ; alist of string pairs
            (default '())))

(define (sysctl-configuration-settings->sysctl.conf settings)
  "Return a file for @command{sysctl} to set kernel parameters as specified by
@var{settings}."
  (apply mixed-text-file "sysctl.conf"
         (append-map (match-lambda
                       ((key . value)
                        (list key "=" value "\n")))
                     settings)))

(define sysctl-shepherd-service
  (match-lambda
    (($ <sysctl-configuration> sysctl settings)
     (let ((sysctl.conf
            (sysctl-configuration-settings->sysctl.conf settings)))
       (shepherd-service
        (documentation "Configure kernel parameters at boot.")
        (provision '(sysctl))
        (start #~(lambda _
                   (zero? (system* #$sysctl "--load" #$sysctl.conf))))
        (one-shot? #t))))))

(define sysctl-service-type
  (service-type
   (name 'sysctl)
   (extensions
    (list (service-extension shepherd-root-service-type
                             (compose list sysctl-shepherd-service))))
   (compose concatenate)
   (extend (lambda (config settings)
             (sysctl-configuration
              (inherit config)
              (settings (append (sysctl-configuration-settings config)
                                settings)))))
   (default-value (sysctl-configuration))))
d></tr>
<tr><td><span title='2015-07-04 12:13:01 +0300'>2015-07-04</span></td><td><a href='/guix/commit/AUTHORS?id=e7c48ee9519aa5cd094f3326a4caeccba072e9fd'>Clean up 'THANKS' and 'AUTHORS'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* THANKS: Add Konrad Hinsen, Cyprien Nicolas, Yakkala Yagnesh Raghava
  and Alexander Shendi.  Remove Federico Beffa, Marek Benc, John
  Darrington, rekado, Cyrill Schenkel and Andy Wingo because they are
  placed in AUTHORS.  Move Amirouche Boubekki and Alex Kost to ...
* AUTHORS: ... here.  Add Arne Babenhauserheide, Ian Denhardt, Kevin
  Lemonnier, Mathieu Lirzin, Pierre-Antoine Rault and Ben Woodcroft.
  Fix some names and emails.
</span></span></td><td>Alex Kost</td></tr>
<tr><td><span title='2015-06-27 20:26:06 +0300'>2015-06-27</span></td><td><a href='/guix/commit/AUTHORS?id=1d642af9872949633b1084f53352f3c851f41810'>Add Claes Wallin to 'AUTHORS'.</a></td><td>Alex Kost</td></tr>
<tr><td><span title='2015-04-26 21:38:37 -0400'>2015-04-26</span></td><td><a href='/guix/commit/AUTHORS?id=6bc24063155d897c6c80a192e48bd9f61cb9014e'>gnu: Add guile-minikanren.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/guile.scm (guile-minikanren): New variable.
</span></span></td><td>Christopher Allan Webber</td></tr>
<tr><td><span title='2015-04-05 23:15:20 +0200'>2015-04-05</span></td><td><a href='/guix/commit/AUTHORS?id=bc45ceb5ffb445ca26a6cd5ac34f39d0dedd8504'>Add Andy to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2015-03-09 20:26:44 -0400'>2015-03-09</span></td><td><a href='/guix/commit/AUTHORS?id=1cf0814d4d89737d7a61bc64650ea5ac58fff7cb'>Add Paul to 'AUTHORS'.</a></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2015-03-09 23:51:43 +0100'>2015-03-09</span></td><td><a href='/guix/commit/AUTHORS?id=e92da92d63d0b50d462fc3608b19d18ac239d87b'>Add Alexander to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>