Fully-qualify paths to zfs, zpool commands

We now e.g. have a cron job on cerebro-backup which calls
these scripts, where /sbin is not on the $PATH.

ROOT/DEBIAN/control

@@ -3,7 +3,7 @@ Priority: optional
 Section: otherosfs
 Maintainer: Frank Lee <rl201@cam.ac.uk>
 Architecture: all
-Version: 0.9-ch62
+Version: 0.9-ch63
 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

 #!/bin/bash
 # To create a new host in the database
 
+ZFSCMD=/sbin/zfs
+ZPOOLCMD=/sbin/zpool
+
 if [ -z $1 ] ; then
   echo Use: $0 hostname [flag [flag [...]]]
   echo Known flags: postgres, mysql
@@ -16,11 +19,11 @@ FQDN=`getent hosts $HN | awk ' { print $2 } '`
 echo Searching for existing ZFS ... 
 # Find an existing ZFS for this host: 
 # Never use zroot
-ZPS=` zpool list -H -o name | grep -v zroot`
+ZPS=`$ZPOOLCMD list -H -o name | grep -v zroot`
 TGT=''
 for ZPOOL in $ZPS ; do
  if [ -z $TGT ] ; then
-  if zfs list -H -o name $ZPOOL/$FQDN >/dev/null 2>&1 ; then
+  if $ZFSCMD list -H -o name $ZPOOL/$FQDN >/dev/null 2>&1 ; then
    TGT=$ZPOOL/$FQDN
   fi
  fi
@@ -33,15 +36,15 @@ done
 if [ -z $TGT ] ; then
  echo No existing ZFS found
  # Find emptiest zpool
- ZPOOL=`zfs list -H -oname -S avail -d0 | grep -v zroot | head -n1`
+ ZPOOL=`$ZFSCMD list -H -oname -S avail -d0 | grep -v zroot | head -n1`
  TGT=$ZPOOL/$FQDN
  echo Using $ZPOOL
 fi
 
 function ensurezfs() {
  ZFS=$1
-if ! zfs list $ZFS >/dev/null 2>&1; then
- zfs create $ZFS
+if ! $ZFSCMD list $ZFS >/dev/null 2>&1; then
+ $ZFSCMD create $ZFS
 fi
 }
 
@@ -129,7 +132,7 @@ function getsshkey() {
 HOSTID=`ensurehost $FQDN`
 echo Host ID is $HOSTID
 ensurezfs $TGT
-zfs set sharenfs=ro=${FQDN},no_root_squash $TGT
+$ZFSCMD set sharenfs=ro=${FQDN},no_root_squash $TGT
 
 # Do root backup
 backupdir $FQDN $TGT/zfs-rsnap /

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

@@ -2,10 +2,13 @@
 # To create a new backup task in the database, perhaps to back up a particular directory 
 # on an existing machine. 
 
+ZFSCMD=/sbin/zfs
+ZPOOLCMD=/sbin/zpool
+
 function ensurezfs() {
  ZFS=$(echo $1| sed 's@//*@/@g')
-if ! zfs list $ZFS >/dev/null 2>&1; then
- zfs create -p $ZFS
+if ! $ZFSCMD list $ZFS >/dev/null 2>&1; then
+ $ZFSCMD create -p $ZFS
 fi
 }
 
@@ -109,11 +112,11 @@ FQDN=`getent hosts $HN | awk ' { print $2 } '`
 echo Searching for existing ZFS ... 
 # Find an existing ZFS for this host and directory: 
 # Never use zroot
-ZPS=` zpool list -H -o name | grep -v zroot`
+ZPS=`$ZPOOLCMD list -H -o name | grep -v zroot`
 TGT=''
 for Z in $ZPS ; do
  if [ -z $TGT ] ; then
-  if zfs list -H -o name $Z/${FQDN}${BACKUP_PATH} >/dev/null 2>&1 ; then
+  if $ZFSCMD list -H -o name $Z/${FQDN}${BACKUP_PATH} >/dev/null 2>&1 ; then
    TGT=$Z/${FQDN}${BACKUP_PATH}
   fi
  fi
@@ -125,8 +128,8 @@ done
 if [ -z $TGT ] ; then
  echo No existing ZFS found
  if [ -z "$ZPOOL" ] ; then
-  # Find emptiest zpool
-  ZPOOL=`zfs list -H -oname -S avail -d0 | grep -v zroot | head -n1`
+  # Find emptiest zpool. We have to use $ZFSCMD in order to sort via "-S avail"
+  ZPOOL=`$ZFSCMD list -H -oname -S avail -d0 | grep -v zroot | head -n1`
  fi 
  TGT=$ZPOOL/$FQDN/${BACKUP_PATH}
  echo Using $ZPOOL
@@ -136,12 +139,12 @@ TGT=$(echo $TGT | sed 's@//*@/@g')
 HOSTID=`ensurehost $FQDN`
 echo Host ID is $HOSTID
 ensurezfs $TGT
-zfs set sharenfs=ro=${FQDN},no_root_squash $TGT
+$ZFSCMD set sharenfs=ro=${FQDN},no_root_squash $TGT
 
 # Create the backup task
 backupdir $FQDN $TGT ${BACKUP_PATH}
 # set ssh key in known_hosts
 getsshkey $FQDN
-zfs set quota=${QUOTA} $TGT
+$ZFSCMD set quota=${QUOTA} $TGT
 
 dosql "update host set disabled=false where hostname='$FQDN';"