;;; 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))))
JSON a required dependency.</a><span class='msg-avail'>...</span></td><td>Eric Bavier</td></tr>
<tr><td><span title='2018-11-23 15:42:00 +0100'>2018-11-23</span></td><td><a href='/guix/commit/README?id=60e1c1099fc3d73ed7d3235e71aae5d00ab7d773'>Update Guile-SQLite3 URL everywhere.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-09-04 17:25:11 +0200'>2018-09-04</span></td><td><a href='/guix/commit/README?id=ca719424455465fca4b872c371daf2a46de88b33'>Switch to Guile-Gcrypt.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-06-27 16:58:59 +0200'>2018-06-27</span></td><td><a href='/guix/commit/README?id=fc6cbb311c5a1acb9cf1d5422fbf1bc23da31d55'>doc: Specify Guile-SQLite3 minimum version.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-06-14 11:16:58 +0200'>2018-06-14</span></td><td><a href='/guix/commit/README?id=c5a2e1ffcb029f50c4c18352cf378b61c41c625e'>build: Require Guile-SQLite3.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-02-26 18:19:34 +0100'>2018-02-26</span></td><td><a href='/guix/commit/README?id=1d84d7bf6052c0c80bd212d4524876576e9817d4'>build: Require Guile &gt;= 2.0.13.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-01-07 23:47:22 +0100'>2018-01-07</span></td><td><a href='/guix/commit/README?id=06e3a5181efa0ea83bb6608d3cbfba5caa56d7e9'>doc: Mark zlib as mandatory, libbz2 as optional.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-01-01 18:21:55 +0100'>2018-01-01</span></td><td><a href='/guix/commit/README?id=397cd9cc416c677e84fb4bb6efef5f99d1d2394f'>doc: Update requirements in 'README'.</a><span class='msg-avail'>...</span></td><td>Mathieu Lirzin</td></tr>
<tr><td><span title='2017-09-25 00:12:49 +0200'>2017-09-25</span></td><td><a href='/guix/commit/README?id=e8d8ecde04a988f04642d754eccc16a14e0cdc53'>README: Replace http:// with https:// where applicable.</a></td><td>Marius Bakke</td></tr>