ports/133072: [patch] net/isc-dhcp30-server, net/isc-dhcp30-server: check configuration file before restart

[Eygene Ryabinkin]

>Number:         133072
>Category:       ports
>Synopsis:       [patch] net/isc-dhcp30-server, net/isc-dhcp30-server: check configuration file before restart
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-ports-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Mar 25 20:00:02 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Eygene Ryabinkin
>Release:        FreeBSD 7.2-PRERELEASE amd64
>Organization:
Code Labs
>Environment:

System: FreeBSD 7.2-PRERELEASE amd64

>Description:

Had just been beaten by the following (silly) error: I had made a
mistake in the DHCP configuration file, restarted daemon and started to
scratch my head in order to understarnd why clients aren't getting their
IPs and other stuff.  I understarnd that it is my fault, but if rc.d
script will be able to test configuration and refuse to start with the
broken config file -- it will be great.

Moreover, there is no point in doing restart with the broken
configuration file -- it is better to leave the running instance.

>How-To-Repeat:

Make a mistake in the configuration file and do
'/usr/local/etc/rc.d/isc-dhcpd restart'.  You'll see the following
output:
-----
Stopping dhcpd.
Starting dhcpd.
-----
Sounds like everything is good, but in reality dhcpd daemon will not
be running.

>Fix:

The following patch adds the check both to the rc.d script for DHCPD 3.0
and 3.1.  I had tested it for 3.0, but it should also work for 3.1.

--- implement-configuration-file-check.diff begins here ---
>From 5d719245842864e73515d976b8a32f20a9437db3 Mon Sep 17 00:00:00 2001
From: Eygene Ryabinkin <rea-fbsd at codelabs.ru>
Date: Wed, 25 Mar 2009 22:29:31 +0300

This feature is very handy, because when 'restart' cmd is run with the
broken configuration file, rc.d script will show that it stops and
starts the daemon.  And one will discover that dhcp daemon isn't running
only on the next restart or looking at the process list -- not cool.

Signed-off-by: Eygene Ryabinkin <rea-fbsd at codelabs.ru>
---
 net/isc-dhcp30-server/files/isc-dhcpd.in |   20 ++++++++++++++++++++
 net/isc-dhcp31-server/files/isc-dhcpd.in |   20 ++++++++++++++++++++
 2 files changed, 40 insertions(+), 0 deletions(-)

diff --git a/net/isc-dhcp30-server/files/isc-dhcpd.in b/net/isc-dhcp30-server/files/isc-dhcpd.in
index 9532d91..0bc65bb 100644
--- a/net/isc-dhcp30-server/files/isc-dhcpd.in
+++ b/net/isc-dhcp30-server/files/isc-dhcpd.in
@@ -701,6 +701,25 @@ dhcpd_uninstall ()
 	fi
 }
 
+dhcpd_checkconfig ()
+{
+	local rc_flags_saved rc_flags_our
+	rc_flags_saved="$rc_flags"
+	setup_flags
+	# Eliminate '-q' flag if it is present
+	rc_flags_our=`echo "${rc_flags}" | sed -Ee's/(^-q | -q | -q$)'//`
+	rc_flags="${rc_flags_saved}"
+	if ${command} -t -q ${rc_flags_our}; then
+		true
+	else
+		echo "Configuration file sanity check failed:"
+		echo "======================================="
+		${command} -t ${rc_flags_our}
+		echo "======================================="
+		false
+	fi
+}
+
 rcvar=${name}_enable
 load_rc_config ${name}
 
@@ -719,6 +738,7 @@ pidfile=${_dhcpd_pidfile}
 required_files=${dhcpd_conf}
 start_precmd=${name}_precmd
 stop_postcmd=${name}_postcmd
+restart_precmd="dhcpd_checkconfig"
 install_cmd=dhcpd_install
 uninstall_cmd=dhcpd_uninstall
 extra_commands="install uninstall"
diff --git a/net/isc-dhcp31-server/files/isc-dhcpd.in b/net/isc-dhcp31-server/files/isc-dhcpd.in
index 6ed05f8..b526bfb 100644
--- a/net/isc-dhcp31-server/files/isc-dhcpd.in
+++ b/net/isc-dhcp31-server/files/isc-dhcpd.in
@@ -700,6 +700,25 @@ dhcpd_uninstall ()
 	fi
 }
 
+dhcpd_checkconfig ()
+{
+	local rc_flags_saved rc_flags_our
+	rc_flags_saved="$rc_flags"
+	setup_flags
+	# Eliminate '-q' flag if it is present
+	rc_flags_our=`echo "${rc_flags}" | sed -Ee's/(^-q | -q | -q$)'//`
+	rc_flags="${rc_flags_saved}"
+	if ${command} -t -q ${rc_flags_our}; then
+		true
+	else
+		echo "Configuration file sanity check failed:"
+		echo "======================================="
+		${command} -t ${rc_flags_our}
+		echo "======================================="
+		false
+	fi
+}
+
 rcvar=${name}_enable
 load_rc_config ${name}
 
@@ -718,6 +737,7 @@ pidfile=${_dhcpd_pidfile}
 required_files=${dhcpd_conf}
 start_precmd=${name}_precmd
 stop_postcmd=${name}_postcmd
+restart_precmd="dhcpd_checkconfig"
 install_cmd=dhcpd_install
 uninstall_cmd=dhcpd_uninstall
 extra_commands="install uninstall"
-- 
1.6.1.3
--- implement-configuration-file-check.diff ends here ---
>Release-Note:
>Audit-Trail:
>Unformatted: