CLOUDSTACK-6989: Add 3 strikes rule for RvR freezing detection

Sometime in VR ntpd would move time backward to keep sync with NTP server, which
can result in false alarm of keepalived monitering process.

This patch adds 3 strikes for keepalived process dead detection to avoid falsely
shutdown keepalived process due to time adjustment for only once.

Author: Sheng Yang

systemvm/patches/debian/config/root/redundant_router/check_heartbeat.sh.templ

@@ -17,12 +17,27 @@
 # under the License.
 
 
+STRIKE_FILE="[RROUTER_BIN_PATH]/keepalived.strikes"
+
 if [ -e [RROUTER_BIN_PATH]/keepalived.ts2 ]
 then
     lasttime=$(cat [RROUTER_BIN_PATH]/keepalived.ts2)
     thistime=$(cat [RROUTER_BIN_PATH]/keepalived.ts)
     diff=$(($thistime - $lasttime))
+    s=0
     if [ $diff -lt 30 ]
+    then
+        if [ -e $STRIKE_FILE ]
+        then
+            s=`cat $STRIKE_FILE 2>/dev/null`
+        fi
+        s=$(($s+1))
+        echo $s > $STRIKE_FILE
+    else
+        rm $STRIKE_FILE
+    fi
+    #3 strikes rule
+    if [ $s -gt 2 ]
     then
         echo Keepalived process is dead! >> [RROUTER_LOG]
         [RROUTER_BIN_PATH]/services.sh stop >> [RROUTER_LOG] 2>&1