DRBD Autodemote

drbd-autodemote

#!/usr/bin/env bash
if [ -z "$1" ]
then
  echo "Please specify a resource"
  echo "  drbd-autodemote r0"
  exit 1
fi

resource="$1"

# verify that resource is connected
if ! /sbin/drbdadm cstate "$resource" 2>/dev/null | grep "^Connected$" > /dev/null
then
  echo "Could not demote $resource, resource is not connected"
  exit 1
fi

# verify that resource is uptodate
if ! /sbin/drbdadm dstate "$resource" 2>/dev/null | grep "^UpToDate/UpToDate$" > /dev/null
then
  echo "Could not demote $resource, resource is not up to date"
  exit 1
fi

# verify that resource is primary
if ! /sbin/drbdadm role "$resource" 2>/dev/null | grep "^Primary/Secondary$" > /dev/null
then
  echo "Could not demote $resource, resource is not primary"
  exit 1
fi

# if this resource is mounted, stop docker, kill other processes associated, and unmount
mountpoint=$(drbd-overview | grep "[0-9]:$resource\/[0-9]\s\+Connected\s\+Primary/Secondary\s\+UpToDate/UpToDate" | awk '{print $7}')
if [ ! -z "$mountpoint" ]
then
  service docker stop
  volume_in_use=1
  while [ ! -z $volume_in_use ]
  do
    pids=$(lsof -n | grep "$mountpoint" | awk '{print $2}' | uniq)
    if [ ! -z "$pids" ]
    then
      echo "Killing $pids"
      kill $pids
      sleep 1
    else
      volume_in_use=
    fi
  done
  umount "$mountpoint"
fi

#finally set the resource to secondary
/sbin/drbdadm secondary "$resource" 2>/dev/null