NobMail

diff --git a/helper-scripts/backup_and_restore.sh b/helper-scripts/backup_and_restore.sh
index a34196f9..20ba9600 100755
--- a/helper-scripts/backup_and_restore.sh
+++ b/helper-scripts/backup_and_restore.sh
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+DEBIAN_DOCKER_IMAGE="debian:buster-slim"
+
 if [[ ! -z ${MAILCOW_BACKUP_LOCATION} ]]; then
   BACKUP_LOCATION="${MAILCOW_BACKUP_LOCATION}"
 fi
@@ -79,32 +81,32 @@ function backup() {
       docker run --name mailcow-backup --rm \
         -v ${BACKUP_LOCATION}/mailcow-${DATE}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_vmail-vol-1):/vmail:ro \
-        debian:stretch-slim /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_vmail.tar.gz /vmail
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_vmail.tar.gz /vmail
       ;;&
     crypt|all)
       docker run --name mailcow-backup --rm \
         -v ${BACKUP_LOCATION}/mailcow-${DATE}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_crypt-vol-1):/crypt:ro \
-        debian:stretch-slim /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_crypt.tar.gz /crypt
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_crypt.tar.gz /crypt
       ;;&
     redis|all)
       docker exec $(docker ps -qf name=redis-mailcow) redis-cli save
       docker run --name mailcow-backup --rm \
         -v ${BACKUP_LOCATION}/mailcow-${DATE}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_redis-vol-1):/redis:ro \
-        debian:stretch-slim /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_redis.tar.gz /redis
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_redis.tar.gz /redis
       ;;&
     rspamd|all)
       docker run --name mailcow-backup --rm \
         -v ${BACKUP_LOCATION}/mailcow-${DATE}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_rspamd-vol-1):/rspamd:ro \
-        debian:stretch-slim /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_rspamd.tar.gz /rspamd
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_rspamd.tar.gz /rspamd
       ;;&
     postfix|all)
       docker run --name mailcow-backup --rm \
         -v ${BACKUP_LOCATION}/mailcow-${DATE}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_postfix-vol-1):/postfix:ro \
-        debian:stretch-slim /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_postfix.tar.gz /postfix
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar --warning='no-file-ignored' --use-compress-program="gzip --rsyncable --best" -Pcvpf /backup/backup_postfix.tar.gz /postfix
       ;;&
     mysql|all)
       SQLIMAGE=$(grep -iEo '(mysql|mariadb)\:.+' ${COMPOSE_FILE})
@@ -152,7 +154,7 @@ function restore() {
       docker run -it --name mailcow-backup --rm \
         -v ${RESTORE_LOCATION}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_vmail-vol-1):/vmail \
-        debian:stretch-slim /bin/tar -Pxvzf /backup/backup_vmail.tar.gz
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar -Pxvzf /backup/backup_vmail.tar.gz
       docker start $(docker ps -aqf name=dovecot-mailcow)
       echo
       echo "In most cases it is not required to run a full resync, you can run the command printed below at any time after testing wether the restore process broke a mailbox:"
@@ -171,7 +173,7 @@ function restore() {
       docker run -it --name mailcow-backup --rm \
         -v ${RESTORE_LOCATION}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_redis-vol-1):/redis \
-        debian:stretch-slim /bin/tar -Pxvzf /backup/backup_redis.tar.gz
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar -Pxvzf /backup/backup_redis.tar.gz
       docker start $(docker ps -aqf name=redis-mailcow)
       ;;
     crypt)
@@ -179,7 +181,7 @@ function restore() {
       docker run -it --name mailcow-backup --rm \
         -v ${RESTORE_LOCATION}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_crypt-vol-1):/crypt \
-        debian:stretch-slim /bin/tar -Pxvzf /backup/backup_crypt.tar.gz
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar -Pxvzf /backup/backup_crypt.tar.gz
       docker start $(docker ps -aqf name=dovecot-mailcow)
       ;;
     rspamd)
@@ -187,7 +189,7 @@ function restore() {
       docker run -it --name mailcow-backup --rm \
         -v ${RESTORE_LOCATION}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_rspamd-vol-1):/rspamd \
-        debian:stretch-slim /bin/tar -Pxvzf /backup/backup_rspamd.tar.gz
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar -Pxvzf /backup/backup_rspamd.tar.gz
       docker start $(docker ps -aqf name=rspamd-mailcow)
       ;;
     postfix)
@@ -195,7 +197,7 @@ function restore() {
       docker run -it --name mailcow-backup --rm \
         -v ${RESTORE_LOCATION}:/backup \
         -v $(docker volume ls -qf name=${CMPS_PRJ}_postfix-vol-1):/postfix \
-        debian:stretch-slim /bin/tar -Pxvzf /backup/backup_postfix.tar.gz
+        ${DEBIAN_DOCKER_IMAGE} /bin/tar -Pxvzf /backup/backup_postfix.tar.gz
       docker start $(docker ps -aqf name=postfix-mailcow)
       ;;
     mysql)