tools: Add script to modify next-server in DHCP

Signed-off-by: David Galloway <dgallowa@redhat.com>

diff --git a/tools/set-next-server.sh b/tools/set-next-server.sh
new file mode 100644 (file)
index 0000000..c935ea6
--- /dev/null
+++ b/tools/set-next-server.sh
@@ -0,0 +1,71 @@
+#!/bin/bash
+# Modifies dhcp config file to add or remove a next-server and filename
+# The fog next-server and filename are the default for all DHCP hosts so
+# entering 'cobbler' for $2 adds its next-server and filename.
+# Setting 'fog' for $2 just removes it so the host entry uses the global default.
+#
+# This script should live on the DHCP server somewhere executable
+#
+# NOTE: DHCP entries *must* be in the following format (including domain)
+# host foo.front.sepia.ceph.com {
+#   hardware ethernet: aa:bb:cc:11:22:33;
+#   fixed-address 1.2.3.4;
+# }
+
+if [ $# -ne 2 ]; then
+  echo "Usage: $(basename $0) hostname [cobbler|fog]"
+  echo
+  echo "Example: \`$(basename $0) mira042 cobbler\` would add Cobbler's next-server and filename to mira042's DHCP entry"
+  echo
+  exit 1
+elif [ "$2" != "cobbler" ] && [ "$2" != "fog" ]; then
+  echo "Unrecognized option $2.  Must use 'cobbler' or 'fog'"
+  exit 1
+else
+  host=$(echo $1 | cut -d '.' -f1)
+fi
+
+set -x
+
+dhcpconfig="/etc/dhcp/dhcpd.front.conf"
+timestamp=$(date +%s)
+cobblerip="172.21.0.11"
+cobblerfilename="/pxelinux.0"
+macaddr=$(sed -n "/host ${host}.front.sepia.ceph.com/,/}/p" $dhcpconfig | grep 'hardware ethernet' | awk '{ print $3 }' | tr -d ';')
+ipaddr=$(sed -n "/host ${host}.front.sepia.ceph.com/,/}/p" $dhcpconfig | grep 'fixed-address' | awk '{ print $2 }' | tr -d ';')
+linenum=$(grep -n $host $dhcpconfig | cut -d ':' -f1)
+
+if [ -z "$macaddr" ]; then
+  echo "No MAC address found for $host"
+  exit 1
+elif [ -z "$ipaddr" ]; then
+  echo "No IP address found for $host"
+  exit 1
+elif [ -z "$linenum" ]; then
+  echo "Unable to determine line number for $host entry"
+  exit 1
+fi
+
+# Back up dhcp config
+cp $dhcpconfig ${dhcpconfig}_$timestamp.bak
+
+# Delete
+sed -i "/host ${host}.front.sepia.ceph.com {/,/}/d" $dhcpconfig
+
+if [ "$2" == "cobbler" ]; then
+  sed -i "${linenum} i \    host ${host}.front.sepia.ceph.com {\n\      hardware ethernet $macaddr;\n\      fixed-address $ipaddr;\n\      next-server $cobblerip;\n\      filename \"$cobblerfilename\";\n\    }" $dhcpconfig
+elif [ "$2" == "fog" ]; then
+  sed -i "${linenum} i \    host ${host}.front.sepia.ceph.com {\n\      hardware ethernet $macaddr;\n\      fixed-address $ipaddr;\n\    }" $dhcpconfig
+fi
+
+dhcpd -q -t -cf $dhcpconfig
+
+if [ $? != 0 ]; then
+  mv $dhcpconfig ${dhcpconfig}_$timestamp.broken
+  mv ${dhcpconfig}_$timestamp.bak $dhcpconfig
+  echo "New config failed config test.  Restored backup."
+  exit 1
+else
+  rm ${dhcpconfig}_$timestamp.bak
+  service dhcpd restart
+fi