From a023cca8d90cfdc7114bbdaa886c52b324075fb6 Mon Sep 17 00:00:00 2001
From: Ludovic Courtès <ludo@gnu.org>
Date: Sun, 14 Sep 2014 23:01:23 +0200
Subject: services: Add 'dhcp-client-service'.
* gnu/services/networking.scm (dhcp-client-service): New procedure.
* doc/guix.texi (Networking Services): Document it.
---
doc/guix.texi | 6 ++++++
gnu/services/networking.scm | 33 +++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+)
diff --git a/doc/guix.texi b/doc/guix.texi
index 8c68c1a743..1c1a04c75c 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -3449,6 +3449,12 @@ Run @var{udev}, which populates the @file{/dev} directory dynamically.
The @code{(gnu system networking)} module provides services to configure
the network interface.
+@cindex DHCP, networking service
+@deffn {Monadic Procedure} dhcp-client-service [#:dhcp @var{isc-dhcp}]
+Return a service that runs @var{dhcp}, a Dynamic Host Configuration
+Protocol (DHCP) client, on all the non-loopback network interfaces.
+@end deffn
+
@deffn {Monadic Procedure} static-networking-service @var{interface} @var{ip} @
[#:gateway #f] [#:name-services @code{'()}]
Return a service that starts @var{interface} with address @var{ip}. If
diff --git a/gnu/services/networking.scm b/gnu/services/networking.scm
index ce924a55bf..ff7bd7fde9 100644
--- a/gnu/services/networking.scm
+++ b/gnu/services/networking.scm
@@ -25,6 +25,7 @@ (define-module (gnu services networking)
#:use-module (guix gexp)
#:use-module (guix monads)
#:export (static-networking-service
+ dhcp-client-service
tor-service))
;;; Commentary:
@@ -94,6 +95,38 @@ (define* (static-networking-service interface ip
#t)))))
(respawn? #f)))))
+(define* (dhcp-client-service #:key (dhcp isc-dhcp))
+ "Return a service that runs @var{dhcp}, a Dynamic Host Configuration
+Protocol (DHCP) client, on all the non-loopback network interfaces."
+
+ (define dhclient
+ #~(string-append #$dhcp "/sbin/dhclient"))
+
+ (define pid-file
+ "/var/run/dhclient.pid")
+
+ (with-monad %store-monad
+ (return (service
+ (documentation
+ "Set up networking via DHCP.")
+ (requirement '(user-processes udev))
+ (provision '(networking))
+ (start #~(lambda _
+ ;; When invoked without any arguments, 'dhclient'
+ ;; discovers all non-loopback interfaces *that are
+ ;; up*. However, the relevant interfaces are
+ ;; typically down at this point. Thus we perform our
+ ;; own interface discovery here.
+ (let* ((valid? (negate loopback-network-interface?))
+ (ifaces (filter valid?
+ (all-network-interfaces)))
+ (pid (fork+exec-command
+ (cons* #$dhclient "-pf" #$pid-file
+ ifaces))))
+ (and (zero? (cdr (waitpid pid)))
+ (call-with-input-file #$pid-file read)))))
+ (stop #~(make-kill-destructor))))))
+
(define* (tor-service #:key (tor tor))
"Return a service to run the @uref{https://torproject.org,Tor} daemon.
--
cgit v1.2.3