rework NM-dispatcher/dhclient detection

The packaged NM dispatcher and dhclient scripts provide the same
functionality. Only one should be active depending on the system
configuration.

Instead of guessing in the NM dispatcher script whether the dhclient
script is executed, check in the dhclient script whether it is called
from a NM dispatcher script (the 11-dhclient script included in the
dhcp-client package).

This is simpler and it removes dependency on the 11-dhclient script.

chrony-nm-dispatcher-dhcp.patch

@@ -1,38 +1,17 @@
-From 1b29e43133d992e735ffbf87d79f008994479036 Mon Sep 17 00:00:00 2001
 From: Robert Fairley <rfairley@redhat.com>
 Date: Wed, 17 Jun 2020 10:14:19 -0400
-Subject: [PATCH] examples/nm-dispatcher.dhcp: use sysconfig, detect dhclient
+Subject: [PATCH] examples/nm-dispatcher.dhcp: use sysconfig
 
 Use the PEERNTP and NTPSERVERARGS environment variables from
-/etc/sysconfig/network{-scripts}. Detect a dhclient install to avoid a
+/etc/sysconfig/network{-scripts}.
-redundant operation with the 11-dhclient NM dispatcher in the
-dhcp-client package.
 
 Co-Authored-By: Christian Glombek <cglombek@redhat.com>
----
- examples/chrony.nm-dispatcher.dhcp | 21 +++++++++++++++++++--
- 1 file changed, 19 insertions(+), 2 deletions(-)
 
 diff --git a/examples/chrony.nm-dispatcher.dhcp b/examples/chrony.nm-dispatcher.dhcp
 index 6ea4c37..a6ad35a 100644
 --- a/examples/chrony.nm-dispatcher.dhcp
 +++ b/examples/chrony.nm-dispatcher.dhcp
-@@ -6,21 +6,39 @@
+@@ -6,16 +6,24 @@
- 
- export LC_ALL=C
- 
-+# If a dhclient installation is present, avoid a redundant operation
-+# in case dhclient handles NTP server config through its own chrony config script,
-+# exec'ed by NetworkManager's 11-dhclient dispatcher script.
-+# In RHCOS, 11-dhclient is excluded and not shipped with base image.
-+[ -e /usr/sbin/dhclient ] && \
-+    [ -e /etc/dhcp/dhclient.d/chrony.sh ] && \
-+    [ -e /etc/NetworkManager/dispatcher.d/11-dhclient -o \
-+      -e /usr/lib/NetworkManager/dispatcher.d/11-dhclient ] && \
-+    exit 0
-+
- interface=$1
- action=$2
  
  chronyc=/usr/bin/chronyc
  default_server_options=iburst

chrony.dhclient

@@ -4,6 +4,9 @@ CHRONY_SOURCEDIR=/run/chrony-dhcp
 SERVERFILE=$CHRONY_SOURCEDIR/$interface.sources
 
 chrony_config() {
+	# Disable modifications if called from a NM dispatcher script
+	[ -n "$NM_DISPATCHER_ACTION" ] && return 0
+
 	rm -f "$SERVERFILE"
 	if [ "$PEERNTP" != "no" ]; then
 		mkdir -p $CHRONY_SOURCEDIR
@@ -15,6 +18,8 @@ chrony_config() {
 }
 
 chrony_restore() {
+	[ -n "$NM_DISPATCHER_ACTION" ] && return 0
+
 	if [ -f "$SERVERFILE" ]; then
 		rm -f "$SERVERFILE"
 		/usr/bin/chronyc reload sources > /dev/null 2>&1 || :

chrony.spec

@@ -63,7 +63,7 @@ md5sum -c <<-EOF | (! grep -v 'OK$')
         2d01b94bc1a7b7fb70cbee831488d121  examples/chrony.conf.example2
         96999221eeef476bd49fe97b97503126  examples/chrony.keys.example
         6a3178c4670de7de393d9365e2793740  examples/chrony.logrotate
-        2da011da89727ef009799502d84e7cd0  examples/chrony.nm-dispatcher.dhcp
+        a7054c9352c07384bd7ea0477e6e8a8c  examples/chrony.nm-dispatcher.dhcp
         8f5a98fcb400a482d355b929d04b5518  examples/chrony.nm-dispatcher.onoffline
         32c34c995c59fd1c3ad1616d063ae4a0  examples/chronyd.service
 EOF