#!/bin/bash
# postinst script for xvm-iscsi-config
#
# see: dh_installdeb(1)

set -e

# Source debconf library
. /usr/share/debconf/confmodule

# summary of how this script can be called:
#        * <postinst> `configure' <most-recently-configured-version>
#        * <old-postinst> `abort-upgrade' <new version>
#        * <conflictor's-postinst> `abort-remove' `in-favour' <package>
#          <new-version>
#        * <postinst> `abort-remove'
#        * <deconfigured's-postinst> `abort-deconfigure' `in-favour'
#          <failed-install-package> <version> `removing'
#          <conflicting-package> <version>
# for details, see http://www.debian.org/doc/debian-policy/ or
# the debian-policy package

# dh_installdeb will replace this with shell code automatically
# generated by other debhelper scripts.

#DEBHELPER#

get_current_sessions() {
    for i in $(cd /sys/class/iscsi_session/ && ls); do
        echo $(cat /sys/class/iscsi_connection/connection${i#session}:0/persistent_address) \
$(cat /sys/class/iscsi_host/$(readlink /sys/class/iscsi_session/$i/device | perl -ne '/host\d+/ && print $&')/netdev)
    done | sort
}

get_new_sessions() {
    for i in $(invirt-getconf --ls iscsi.targets); do
	for j in $(invirt-getconf --ls iscsi.targets.$i.ifaces); do
            echo $(invirt-getconf iscsi.targets.$i.ip) $(invirt-getconf iscsi.targets.$i.ifaces.$j)
	done
    done | sort
}

case "$1" in
    configure)
        db_get xvm-iscsi-config/username
        USERNAME="$RET"
        db_get xvm-iscsi-config/password
        PASSWORD="$RET"
        db_stop
        
        OLD_USERNAME=$(invirt-getconf iscsi.username 2>/dev/null)
        OLD_PASSWORD=$(invirt-getconf iscsi.password 2>/dev/null)

        if [ -e /etc/invirt/conf.d/iscsi ]; then
          # invirt.config.run_parts_list excludes backup filenames.
          mv -f /etc/invirt/conf.d/iscsi /etc/invirt/conf.d/iscsi~
        fi
        cat >/etc/invirt/conf.d/iscsi <<EOF
iscsi:
 username: $USERNAME
 password: $PASSWORD
EOF

        # Attempt to determine whether the iSCSI configuration has changed at all
        safe=""

        if [ -z "$2" ]; then
            invoke-rc.d xvm-iscsi-config restart
            invoke-rc.d open-iscsi restart
        elif [[ "$USERNAME" -ne "$OLD_USERNAME" || "$PASSWORD" -ne "$OLD_PASSWORD" ]]; then
            cat <<EOF
xvm-iscsi-config: The login credentials have changed.  Restart iscsi:
  /etc/init.d/xvm-iscsi-config restart
  /etc/init.d/open-iscsi restart
EOF
            safe=no
        fi
        if ! diff <(get_current_sessions) <(get_new_sessions) >/dev/null; then
            if [ -z "$safe" ]; then
		/usr/lib/xvm-iscsi-connect
            else
		echo "  /usr/lib/xvm-iscsi-connect"
            fi
            cat <<EOF
You may want to recreate the LVM nodes:
  lvchange -a ln /dev/xenvg && lvchange -a y /dev/xenvg
This will leave VMs unable to access their disks, so migrate them first.

EOF
        fi
    ;;

    abort-upgrade|abort-remove|abort-deconfigure)
    ;;

    *)
        echo "postinst called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac

exit 0