TrueNAS Scale Backup Script

#!/bin/bash

### TrueNAS-PBS: Backup TrueNAS data sets into Proxmox Backup Server (PBS)
### Written by Chris MacKenzie, 2023
###
### Requires proxmox-backup-client installed on TrueNAS host and an account created in PBS with appropriate permissions.
###
### TODO: Add Log cleanup function with retention policy.

export PBS_PASSWORD=truenas
export PBS_REPOSITORY=truenas@pbs@192.168.0.150:Mirror8

SCRIPTNAME=`basename -s .sh ${0}` # Name of this script minus path and the .sh extension
CUR_DATE=`date +%Y-%m-%d-%H-%M-%S`
LOGDIR=/mnt/StoragePool/backup/Logs # Where to store the logs
LOGNAME="$LOGDIR/$SCRIPTNAME-${CUR_DATE}.log"

STORAGEPOOLS=("StoragePool/backup" "StoragePool/FileStore/NAS-Data" "StoragePool/FileStore/NAS-Media" "StoragePool/FileStore/NAS-Home")
PXAR_NAMES=("backup.pxar" "nas-data.pxar" "nas-media.pxar" "nas-home.pxar") # pxar archive file names for pbs server (in same order as dataset array)

STORAGEPOOL_LENGTH=${#STORAGEPOOLS[@]} # Number of array elements
TEMP_SNAPSHOTNAME="PreBackupSnapshot"
SPEC="" # Specification variable for proxmox-backup-client

MY_DEBUG=0 # Set to 1 to do everything except the calling of proxmox-backup-client, essentially a dry-run


#### Declare Functions
WriteLog () { # Writes to both log and stdout
	echo $1
	echo $1 >> ${LOGNAME}
}

CreateSnapshot () {
	TEMP_SNAPSHOT="$STORAGEPOOL@$TEMP_SNAPSHOTNAME"

	WriteLog " - Creating Snapshot -> $TEMP_SNAPSHOT"
	zfs snapshot $TEMP_SNAPSHOT 2>/dev/nul # Redirect STDERROR to /dev/nul
	EXITCODE=$?
	if [ $EXITCODE != 0 ]; then
        	WriteLog " !! Cannot create snapshot (error $EXITCODE)"
	fi
	return $EXITCODE
}

DeleteSnapshot () {
        TEMP_SNAPSHOT="$STORAGEPOOL@$TEMP_SNAPSHOTNAME"

        WriteLog " - deleting Snapshot -> $TEMP_SNAPSHOT"
        zfs destroy $TEMP_SNAPSHOT 2>/dev/nul # Redirect STDERROR to /dev/nul
        EXITCODE=$?
        if [ $EXITCODE != 0 ]; then
                WriteLog " !! Cannot delete snapshot (error $EXITCODE)"
        fi
        return $EXITCODE
}

CleanUp () {
	WriteLog "Performing CleanUp()"
	for STORAGEPOOL in "${STORAGEPOOLS[@]}"
	do
		DeleteSnapshot $STORAGEPOOL
		EXITCODE=$?
        	if [ $EXITCODE != 0 ]; then
                	WriteLog " !! Error performing CleanUp ($EXITCODE)."
                	WriteLog
                	exit 255
        	fi
	done
}
#### End of Functions

## Create log file and log directory if it does not exist.
ls $LOGDIR >/dev/nul 2>/dev/nul
if [ "$?" != "0" ]; then
	mkdir -m 775 -p $LOGDIR
	if [ "$?" != "0" ]; then
		echo " !! Cannot create log directory $LOGDIR, Aborting."
		exit 255
	fi
fi

touch ${LOGNAME}
if [ "$?" != "0" ]; then
	echo " !! Cannot create logfile $LOGNAME"
	exit 255
fi

## Do Preperations (Create snapshots and build SPEC variable)
WriteLog "Doing Preperations, Please Wait."
for ((i=0; i<STORAGEPOOL_LENGTH; i++))
do
	SPEC="$SPEC ${PXAR_NAMES[$i]}:/mnt/${STORAGEPOOLS[$i]}/.zfs/snapshot/$TEMP_SNAPSHOTNAME/"
        STORAGEPOOL="${STORAGEPOOLS[$i]}"
        CreateSnapshot $STORAGEPOOL
        EXITCODE=$?
        if [ $EXITCODE != 0 ]; then
        	WriteLog " !! Cannot create snapshot (error $EXITCODE), exiting."
                WriteLog
                CleanUp # Attempt Cleanup
                WriteLog
                WriteLog "Backup Aborted."
                exit 255
	fi
done

### Run Backup
WriteLog
WriteLog "SPEC = $SPEC"

if [ $MY_DEBUG -eq 1 ]; then
	WriteLog "Debug Detected."
	CleanUp
	WriteLog
	WriteLog "Debug Exit."
	WriteLog
	exit 0
fi

WriteLog
WriteLog "Starting Backup....."
WriteLog

proxmox-backup-client backup $SPEC >> $LOGNAME 2>&1
EXITCODE=$?
if [ $EXITCODE != 0 ]; then
        WriteLog "proxmox-backup-client failed (error $EXITCODE), aborting."
	CleanUp
        exit 255
fi

WriteLog

CleanUp
EXITCODE=$?
if [ $EXITCODE != 0 ]; then
	WriteLog " !! Error performing CleanUp."
	exit 255
fi

WriteLog
WriteLog "Backup completed successfully."
exit 0