;;; 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-configuration-sysctl
            sysctl-configuration-settings
            sysctl-service-type
            %default-sysctl-settings))

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

(define %default-sysctl-settings
  ;; Default kernel parameters enabled with sysctl.
  '(("fs.protected_hardlinks" . "1")
    ("fs.protected_symlinks" . "1")))

(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 %default-sysctl-settings)))

(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))
   (description "Set Linux kernel parameters under @file{/proc/sys} at system
startup time.")))
1</span></td><td><a href='/guix/commit/gnu/build/shepherd.scm?id=3682bd4003f4c4e313498931c471eeae2efe09b8'>Add (guix least-authority).</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/least-authority.scm: New file.
* Makefile.am (MODULES): Add it.
* gnu/build/shepherd.scm (default-mounts): Make public.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-04-12 23:40:44 +0200'>2022-04-12</span></td><td><a href='/guix/commit/gnu/build/shepherd.scm?id=e1f0c88ea221d846b5a533c4dc88e99e953af63e'>shepherd: Add #:supplementary-groups.</a><span class='msg-avail'>...<span class='msg-tooltip'>To support the argument introduced in Shepherd 0.9.0 when defining
container-bound services.

* gnu/build/shepherd.scm (exec-command*)
(make-forkexec-constructor/container): Add '#:supplementary-groups'.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Leo Nikkilä</td></tr>
<tr><td><span title='2022-04-11 00:25:33 +0200'>2022-04-11</span></td><td><a href='/guix/commit/gnu/build/shepherd.scm?id=f42959662765d1cd47137ff5da09086fc6a62e99'>shepherd: 'fork+exec-command/container' always returns a PID.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes a regression introduced in
938448bf40fc77092859352d2243e2d0c236375f whereby
'fork+exec-command/container' would return #t, then used as the running
value of the 'guix-daemon' service in the installer.  Upon installation
completion, stopping the 'guix-daemon' service would fail with
wrong-type-arg because that #t would be passed to the 'stop' method in
lieu of a PID.

* gnu/build/shepherd.scm (fork+exec-command/container): Return a PID
rather than #t.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-04-11 00:25:33 +0200'>2022-04-11</span></td><td><a href='/guix/commit/gnu/build/shepherd.scm?id=ada530acb1e848daaac027872e6bad067e82207b'>shepherd: 'exec-command*' has a valid default #:directory.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes a regression introduced in
938448bf40fc77092859352d2243e2d0c236375f where 'exec-command*' could
get #:directory #f, in particular when called by
'fork+exec-command/container'.

* gnu/build/shepherd.scm (exec-command*): Add default value for #:directory.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-04-07 00:08:55 +0200'>2022-04-07</span></td><td><a href='/guix/commit/gnu/build/shepherd.scm?id=938448bf40fc77092859352d2243e2d0c236375f'>shepherd: Adjust 'fork+exec-command/container' for the Shepherd 0.9.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/shepherd.scm (exec-command*): New procedure, with code
formerly...
(make-forkexec-constructor/container): ... here.  Use it.
(fork+exec-command/container): Use 'fork+exec-command' only when
CONTAINER-SUPPORT? is false or PID is the current process.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-08-02 14:16:22 -0400'>2021-08-02</span></td><td><a href='/guix/commit/gnu/build/shepherd.scm?id=5b2b834269f74865c8ca6ab5e81f6834228490d4'>build: shepherd: Use autoload to lazily bind Shepherd modules.</a><span class='msg-avail'>...<span class='msg-tooltip'>Instead of imperative module-autoload! directives.

* gnu/build/shepherd.scm: Replace module-autoload! directives by autoload
arguments for define-module.
</span></span></td><td>Maxim Cournoyer</td></tr>