xcat-core/xCAT/postscripts/xcatflowrequest

#!/bin/bash
# IBM(c) 2013  EPL license http://www.eclipse.org/legal/epl-v10.html
# This routine when called, contacts xcatd.  It will return to the caller when xcatd is
# ready to process the request
# It is called by xcatdsklspost before calling getpostscripts.awk
# it is called by remoteshell before calling getcredentials.awk
# For example   xcatflowrequest <ip address of master> 3001
#  Returns
#     0 = good
#     1 = ping/nmap to ip address of master failed (TBD)
#     2 = xcatd never gave goahead
#

#  Here we will test to see if nmap is available
#  if available we will use it to see if the daemon is available
#  If not available we will use ping to the ip address
#  If nmap or ping fail then
#   we will return with exit 1
#


# check bash version, if < 4 then cannot use autodetect of next FD
bashversion=$BASH_VERSION
bashversionnum=`echo $bashversion | cut -d. -f1`

# cleanup before exiting
cleanup()
{
sleeper=$(cat /tmp/sleeperpid.$parpid)
sleeper=$(ps -ef|awk "\$3==$sleeper"|awk '{print $2}')
rm /tmp/goahead.$parpid
rm /tmp/sleeperpid.$parpid
rm /tmp/killme.$parpid
if [[ $bashversionnum > 3 ]]; then
  exec {REMOTEFD}>&-
else
  exec 50>&-
fi
kill -TERM $sleeper
}

if [[ $bashversionnum > 3 ]]; then
    exec {REMOTEFD}<>/dev/udp/$1/$2
else
    exec 50<>/dev/udp/$1/$2
    echo "resourcerequest: xcatd" >&50
    REMOTEFD=50
fi
echo "resourcerequest: xcatd" >&$REMOTEFD
parpid=$$
touch /tmp/goahead.$parpid
touch /tmp/killme.$parpid
exec 2> /dev/null
RETRY=0
MAX_RETRIES=50
while ! grep 'resourcerequest: ok' /tmp/goahead.$parpid > /dev/null; do
	(
      echo "resourcerequest: xcatd" >&$REMOTEFD
      if [[ $bashversionnum > 3 ]]; then
         exec {LOCALFD}<>/proc/self/stat
      else
        exec 51<>/proc/self/stat
        LOCALFD=51
      fi
      read mystat<&$LOCALFD
      mypid=$(echo $mystat|cut -d " " -f 4)
	  (sleep $(((RANDOM%60)+120)).$((RANDOM%50)); if [ -f /tmp/killme.$parpid ]; then kill -TERM $mypid; fi) &
      echo $! > /tmp/sleeperpid.$parpid
	  exec awk '{print $0 > "/tmp/goahead.'$parpid'";exit}' <&$REMOTEFD
      exec {LOCALFD}>&-
	)
    # limit retries, if we reach the max error out
    RETRY=$(($RETRY+1))
    if [ $RETRY -eq $MAX_RETRIES ]
    then
       cleanup
       exit 2 
    fi
	
done
cleanup
exit 0