Add script to move a backup to another server

i.e. send the ZFS, update db records and copy the config files. The
sql inserts should broadly mirror those done when setting up a new
backup, though with field values matching those in the source database
rather than just using the defaults.

This script has so only been tested for the case of moving a "simple"
backup where a host has a single backup task and no special config.
It's quite likely there'll be bugs to fix for other cases that
we'll find in due course.

ROOT/usr/lib/chem-zfs-backup-server/send-backup-to-server.sh

+#!/bin/bash
+# To move a machine onto a new ZFS
+# Load some settings
+. /etc/default/zfs-backup
+
+# To move a machine from one zpool to another
+function dosql_local() {
+ SQL="$1"
+ psql -A -t -c "$SQL"
+}
+
+function dosql_remote() {
+ SQL="$1"
+ psql -A -h $NEW_SERVER -t -c "$SQL"
+}
+
+function cmd_remote() {
+ CMD="$1"
+ ssh root@$NEW_SERVER $CMD
+}
+
+function create_host_record() {
+ FQDN=$1
+ # NB we start with offline=t,disabled=t whilst we migrate the backup.
+ HOSTID=`dosql_remote "
+ insert into host (hostname, offline, disabled) values ('$FQDN',true,true);
+ select host_id from host where hostname='$FQDN';"`
+ echo $HOSTID
+}
+
+function backuptask() {
+ HOSTID=$1
+ TASKNAME="$2"
+ TARGET=$3
+ SOURCEDIR=$4
+ SOFT=$5
+ HARD=$5
+
+if [ -z "$SOFT" ]; then
+  SOFT=14400
+ fi
+ if [ -z "$HARD" ]; then
+  HARD=86400
+ fi
+ BTID=`dosql_remote "
+ insert into backup_task(host_id,backup_task_name,timeout_soft,timeout_hard,zfs_target,backup_type_id) values
+ ($HOSTID,'$TASKNAME',$SOFT,$HARD,'$TARGET',3);
+ 
+ insert into zfs_rsync_detail (backup_task_id,directory_source) values
+ ((select backup_task_id from backup_task where zfs_target='$TARGET' and host_id=$HOSTID),'$SOURCEDIR');
+
+ select backup_task_id from backup_task natural join host natural join zfs_rsync_detail where hostname='$FQDN' and directory_source='$SOURCEDIR' and backup_type_id=3;"`
+ echo $BTID
+}
+
+function configure_pruning() {
+ CURRENT_TASK_ID=$1
+ NEW_TASK_ID=$2
+ PRUNING_IDS=$(dosql_local "select zfs_pruning_id from zfs_pruning where backup_task_id=$CURRENT_TASK_ID")
+ for PRUNING_ID in $PRUNING_IDS; do
+   PRUNING_AGE=$(dosql_local "select zfs_pruning_age from zfs_pruning where zfs_pruning_id=$PRUNING_ID")
+   PRUNING_COUNT=$(dosql_local "select zfs_pruning_count from zfs_pruning where zfs_pruning_id=$PRUNING_ID")
+   FLAGNAME=$(dosql_local "select flagname from zfs_pruning where zfs_pruning_id=$PRUNING_ID")
+
+   dosql_remote "insert into zfs_pruning (backup_task_id, zfs_pruning_age,zfs_pruning_count,flagname) values 
+   ($NEW_TASK_ID, $PRUNING_AGE, $PRUNING_COUNT, '$FLAGNAME')"
+ done
+}
+ 
+if [ $# -lt 2 ] ; then
+ echo Usage: $0 backup_target_fqdn new_backup_server [zpool_name]
+ echo Moves the named machine to a new server
+ exit 1
+fi
+
+HN=$1
+# Find FQDN for $HN
+FQDN=`getent hosts $HN | awk ' { print $2 } '`
+NEW_SERVER=$2
+ZPOOL_TARGET=$3
+# Which zfs is it already on?
+echo Finding source ZFS for $FQDN
+SOURCES=`zfs list -H -o name | grep -v  zroot | grep /$FQDN$ | sed "sZ/'$FQDN$'ZZ" | wc -l `
+#echo Found $SOURCES possibilities
+if [ $SOURCES != 1 ] ;then
+ echo Found more than one possible ZFS for $HN
+ exit 2
+fi
+
+if ! grep -q ^$NEW_SERVER: $PGPASSFILE ; then
+  echo $NEW_SERVER not found in $PGPASSFILE \(use fqdn?\)
+  exit 5
+fi
+
+
+SOURCE=`zfs list -H -o name | grep -v  zroot | grep /$FQDN$ | sed "sZ/$FQDN\\$ZZ"`
+
+# Which target is it?
+if [ -z "$ZPOOL_TARGET" ] ; then
+ echo Finding a target ZFS automatically
+ ZPOOL=$(cmd_remote "zfs list -H -oname -S avail -d0 | grep -v zroot | head -n1")
+ ZPOOL_TARGET=$ZPOOL
+fi
+
+if ! ssh root@$NEW_SERVER zpool list $ZPOOL_TARGET &>/dev/null ; then
+  echo $ZPOOL_TARGET does not exist on $NEW_SERVER
+  exit 3
+fi
+
+echo moving $FQDN from $SOURCE to $ZPOOL_TARGET on $NEW_SERVER
+
+set -e
+RUNNING=`dosql_local "select count(*) from backup_log natural join backup_task natural join host where hostname='$FQDN' and ended_processing is null and started_processing is not null"`
+RUNNING=`echo $RUNNING` # chomp
+#echo RUNNING $RUNNING
+if ! [ "$RUNNING" = 0 ] ;  then
+ echo $FQDN has a job running
+ exit 3
+fi
+
+# Disable this host locally
+dosql_local "update host set disabled='t' where hostname='$FQDN';"
+# De-queue jobs for this host
+dosql_local "delete from backup_log where backup_task_id in (select backup_task_id from backup_task natural join host where hostname='$FQDN') and ended_processing is null and started_processing is null;"
+
+# Move ZFS
+NOW=$(date +%s)
+zfs snapshot -r $SOURCE/$FQDN@$NOW
+zfs hold zfs-moving $SOURCE/$FQDN@$NOW
+SIZE=`zfs list -H -o used $SOURCE/$FQDN`
+echo Sending  ZFS [ $SIZE]
+zfs send -R $SOURCE/$FQDN@$NOW | mbuffer | ssh root@$NEW_SERVER zfs receive $ZPOOL_TARGET/$FQDN
+CURRENT_HOST_ID=$(dosql_local "select host_id from host where hostname='$FQDN'")
+NEW_HOST_ID=$(create_host_record $FQDN)
+
+# get current tasks
+TASK_IDS=$(dosql_local "select backup_task_id from backup_task where host_id='$CURRENT_HOST_ID'")
+
+# create new tasks
+for TASK_ID in $TASK_IDS; do
+  echo got task $TASK_ID
+
+  SOURCEDIR=$(dosql_local "select directory_source from zfs_rsync_detail where backup_task_id='$TASK_ID'")
+  SOFT=$(dosql_local "select timeout_soft from backup_task where backup_task_id='$TASK_ID'")
+  HARD=$(dosql_local "select timeout_hard from backup_task where backup_task_id='$TASK_ID'")
+  CURRENT_ZFS_TARGET=$(dosql_local "select zfs_target from backup_task where backup_task_id='$TASK_ID'")
+  NEW_ZFS_TARGET=${ZPOOL_TARGET}/$(echo $CURRENT_ZFS_TARGET | cut -d '/' -f 2-)
+  
+  NEW_TASK_ID=$(backuptask $NEW_HOST_ID "$TASKNAME" $NEW_ZFS_TARGET $SOURCEDIR $SOFT $HARD)
+  configure_pruning $TASK_ID $NEW_TASK_ID  
+
+  scp /etc/chem-zfs-backup-server/zfs-rsync.d/${FQDN}_${SOURCEDIR//\//.} $NEW_SERVER:/etc/chem-zfs-backup-server/zfs-rsync.d
+done
+
+dosql_remote "update host set disabled='f',offline='f' where host_id=$NEW_HOST_ID"
+
+
+