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

Use the PEERNTP and NTPSERVERARGS environment variables from
/etc/sysconfig/network{-scripts}. Detect a dhclient install to avoid a
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 @@
 
 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
-server_dir=/var/run/chrony-dhcp
+server_dir=/run/chrony-dhcp
 
 dhcp_server_file=$server_dir/$interface.sources
 # DHCP4_NTP_SERVERS is passed from DHCP options by NetworkManager.
 nm_dhcp_servers=$DHCP4_NTP_SERVERS
 
+[ -f /etc/sysconfig/network ] && . /etc/sysconfig/network
+[ -f /etc/sysconfig/network-scripts/ifcfg-"${interface}" ] && \
+    . /etc/sysconfig/network-scripts/ifcfg-"${interface}"
+
 add_servers_from_dhcp() {
     rm -f "$dhcp_server_file"
+
+    # Don't add NTP servers if PEERNTP=no specified; return early.
+    [ "$PEERNTP" = "no" ] && return
+
     for server in $nm_dhcp_servers; do
-        echo "server $server $default_server_options" >> "$dhcp_server_file"
+        echo "server $server ${NTPSERVERARGS:-$default_server_options}" >> "$dhcp_server_file"
     done
     $chronyc reload sources > /dev/null 2>&1 || :
 }
-- 
2.29.2