gistfile1.txt

#!/usr/bin/env bash

# We need to cat lines with spaces
OLD_IFS=$IFS
IFS=$'\n'
OUTFILE="hosts.file"
NOVA_CREDS=""

# If the credentials file isn't specified we exit
if [ -z $NOVA_CREDS ]; then
  echo "You must provide the location of your OpenStack credential file NOVA_CREDS"
  exit 1
fi

# Source our creds file
. $NOVA_CREDS

# Create a header with what and when we were created
echo "# Created by $0 at $( date )" > $OUTFILE

# Cache our list so we can iterate on it
nova list >> $$.tmp

# Loop over all our instances and create a hosts file out of them
for i in $( cat $$.tmp | grep -v "+---" | grep -v Networks ); do
  hostname=$( echo $i | awk -F'|' '{ print $3 }' | sed 's/ //g' )
  ip=$( echo $i | awk -F'|' '{ print $5 }' | awk -F= '{ print $2 }' | awk -F, '{ print $1 }' | sed 's/ //g' ) 
  if [ -z $ip ]; then
    continue
  fi

  # Save the hosts file somewhere, based on $OUTFILE above
  echo "$ip     $hostname" >> $OUTFILE
done

# Delete our tmp file
rm -f $$.tmp

# Set IFS back to what it was before we started
IFS=$old_IFS