new-backup-rsnapshot better support for postgres backups

The new-backup-rsnapshot script understands a 'postgres' argument, but
this set up a postgres backup in an old style that we no longer use.
This change updates it to do some of the work of setting up a new style
postgres backup and tell the user what else they might need to edit to
make it go; it varies quite a lot depending on server.

ROOT/DEBIAN/control

@@ -3,7 +3,7 @@ Priority: optional
 Section: otherosfs
 Maintainer: Frank Lee <rl201@cam.ac.uk>
 Architecture: all
-Version: 0.9-ch60
+Version: 0.9-ch61
 Depends: zfs-dkms, postgresql-9.5 | postgresql-9.4 , liblockfile-simple-perl, libdbi-perl, libjson-perl, libzfs-perl-chem, libnet-openssh-perl, libdbd-pg-perl, mbuffer, rsync, nfs-kernel-server, pv, libwww-curl-perl
 Description: a backup system using ZFS
  Ported (well, mostly) from FreeBSD to a Sane OS.

ROOT/usr/lib/chem-zfs-backup-server/new-backup-rsnapshot

@@ -67,13 +67,21 @@ function backuptask() {
  FQDN=$1
  TARGET=$2
  DIR=$3
+ SOFT=$4
+ HARD=$5
+ if [ -z "$SOFT" ]; then
+  SOFT=14400
+ fi
+ if [ -z "$HARD" ]; then
+  HARD=86400
+ fi
 BTID=`dosql "
 select backup_task_id from backup_task natural join host natural join zfs_rsync_detail where hostname='$FQDN' and directory_source='$DIR' and backup_type_id=3;"`
 SN=`echo $FQDN | sed s/\\\\..*//`
 if [ -z $BTID ] ; then
  BTID=`dosql "
  insert into backup_task(host_id,backup_task_name,timeout_soft,timeout_hard,zfs_target,backup_type_id) values
- ($HOSTID,'Rsync $DIR on $SN',14400,86400,'$TARGET',3);
+ ($HOSTID,'Rsync $DIR on $SN',$SOFT,$HARD,'$TARGET',3);
  insert into zfs_rsync_detail (backup_task_id,directory_source) values 
  ((select backup_task_id from backup_task where backup_task_name='Rsync $DIR on $SN' and host_id=$HOSTID),'$DIR');
  select backup_task_id from backup_task natural join host natural join zfs_rsync_detail where hostname='$FQDN' and directory_source='$DIR' and backup_type_id=3;"`
@@ -132,7 +140,10 @@ getsshkey $FQDN
 while ! [ -z $1 ] ; do
  case $1 in
   postgres)
-   backupdir $FQDN $TGT/postgresql /var/lib/postgresql
+   backupdir $FQDN $TGT/pgdumps /var/empty 43200 60480
+   echo "Now set up /etc/chem-zfs-backup-server/zfs-rsync.d/${FQDN}_.var.empty to"
+   echo "run your postgres backup task as the PRE command, and you probably also want"
+   echo "to change the prepare script in /etc/chem-zfs-backup-server/zfs-rsync.d/${FQDN}_. too."
    ;;
   mysql)
    backupdir $FQDN $TGT/mysql-files /var/lib/mysql-files