#! /bin/bash
# RHS-2.0 only
# - The script mounts the 'meta-vol' on start 'event' on a known
#   directory (eg. /gluster/lock)
# - Adds the necessary configuration changes for ctdb in smb.conf and
#   restarts smb service.
# - P.S: There are other 'tasks' that need to be done outside this script
#   to get CTDB based failover up and running.

SMB_CONF=/etc/samba/smb.conf

CTDB_MNT=/gluster/lock
PROGNAME="ctdb"
OPTSPEC="volname:"
VOL=
# $META is the volume that will be used by CTDB as a shared filesystem.
# It is not desirable to use this volume for storing 'data' as well.
# META is set to 'all' (viz. a keyword and hence not a legal volume name)
# to prevent the script from running for volumes it was not intended.
# User needs to set META to the volume that serves CTDB lockfile.
META="all"

function parse_args () {
        ARGS=$(getopt -l $OPTSPEC  -name $PROGNAME $@)
        eval set -- "$ARGS"

        while true; do
            case $1 in
                --volname)
                    shift
                    VOL=$1
                ;;

                *)
                     shift
                     break
                ;;

            esac

            shift
        done
}

function add_glusterfs_ctdb_options () {
        PAT="Share Definitions"
        GLUSTER_CTDB_CONFIG="# ctdb config for glusterfs\n\tclustering = yes\n\tidmap backend = tdb2\n"
        exists=`grep "clustering = yes" "$SMB_CONF"`
        if [ "$exists" == "" ]
        then
            sed -i /"$PAT"/i\ "$GLUSTER_CTDB_CONFIG" "$SMB_CONF"
        fi
}

function add_fstab_entry () {
        volname=$1
        mntpt=$2
        mntent="`hostname`:/$volname $mntpt glusterfs defaults,transport=tcp 0 0"
        exists=`grep "^$mntent" /etc/fstab`
        if [ "$exists" == "" ]
        then
            echo "$mntent" >> /etc/fstab
        fi
}

parse_args $@
if [ "$META" = "$VOL" ]
then
    #expects ctdb service to manage smb
    service smb stop
    add_glusterfs_ctdb_options
    mkdir -p $CTDB_MNT
    sleep 5
    mount -t glusterfs `hostname`:$VOL "$CTDB_MNT" && \
        add_fstab_entry $VOL $CTDB_MNT
    chkconfig ctdb on
fi