#!/bin/sh

# https://opensource-information.blogspot.com/2012/08/hast-freebsd-zfs-with-carp-failover.html
# Original script by Freddie Cash <fjwcash@gmail.com>
# Modified by Michael W. Lucas <mwlucas@BlackHelicopters.org>
# and Viktor Petersson <vpetersson@wireload.net>
# Modified by George Kontostanos <gkontos.mail@gmail.com>
 
# The names of the HAST resources, as listed in /etc/hast.conf
resources="disk0 disk1 disk2 disk3 disk4 disk5 disk6 disk7 disk8 disk9"
 
# delay in mounting HAST resource after becoming master
# make your best guess
delay=3
 
# logging
log="local0.debug"
name="failover"
pool="storage"
 
# end of user configurable stuff
 
case "$1" in
 master)
  logger -p $log -t $name "Switching to primary provider for ${resources}."
  sleep ${delay}
 
  # Wait for any "hastd secondary" processes to stop
  for disk in ${resources}; do
   while $( pgrep -lf "hastd: ${disk} \(secondary\)" > /dev/null 2>&1 ); do
    sleep 1
   done
 
   # Switch role for each disk
   hastctl role primary ${disk}
   if [ $? -ne 0 ]; then
    logger -p $log -t $name "Unable to change role to primary for resource ${disk}."
    exit 1
   fi
  done
 
  # Wait for the /dev/hast/* devices to appear
  for disk in ${resources}; do
   for I in $( jot 60 ); do
    [ -c "/dev/hast/${disk}" ] && break
    sleep 0.5
   done
 
   if [ ! -c "/dev/hast/${disk}" ]; then
    logger -p $log -t $name "GEOM provider /dev/hast/${disk} did not appear."
    exit 1
   fi
  done
 
  logger -p $log -t $name "Role for HAST resources ${resources} switched to primary."
 
 
  logger -p $log -t $name "Importing Pool"
  # Import ZFS pool. Do it forcibly as it remembers hostid of
                # the other cluster node.
                out=`zpool import -f "${pool}" 2>&1`
                if [ $? -ne 0 ]; then
                    logger -p local0.error -t hast "ZFS pool import for resource ${resource} failed: ${out}."
                    exit 1
                fi
                logger -p local0.debug -t hast "ZFS pool for resource ${resource} imported."
 
 ;;
 
 slave)
  logger -p $log -t $name "Switching to secondary provider for ${resources}."
 
  # Switch roles for the HAST resources
  zpool list | egrep -q "^${pool} "
         if [ $? -eq 0 ]; then
                 # Forcibly export file pool.
                 out=`zpool export -f "${pool}" 2>&1`
                  if [ $? -ne 0 ]; then
                         logger -p local0.error -t hast "Unable to export pool for resource ${resource}: ${out}."
                         exit 1
                  fi
                 logger -p local0.debug -t hast "ZFS pool for resource ${resource} exported."
         fi
  for disk in ${resources}; do
   sleep $delay
   hastctl role secondary ${disk} 2>&1
   if [ $? -ne 0 ]; then
    logger -p $log -t $name "Unable to switch role to secondary for resource ${disk}."
    exit 1
   fi
   logger -p $log -t $name "Role switched to secondary for resource ${disk}."
  done
 ;;
esac