Fix: bash variables are not quoted (#6022)

* Fix: Double quote variables to prevent word splitting

* Fix `update.sh`: Double quote to prevent word splitting

* Refactor: Remove unnecessary white-spaces.

generate_config.sh

@@ -9,7 +9,7 @@ if [[ "$(uname -r)" =~ ^4\.15\.0-60 ]]; then
 fi
 
 if [[ "$(uname -r)" =~ ^4\.4\. ]]; then
-  if grep -q Ubuntu <<< $(uname -a); then
+  if grep -q Ubuntu <<< "$(uname -a)"; then
     echo "DO NOT RUN mailcow ON THIS UBUNTU KERNEL!";
     echo "Please update to linux-generic-hwe-16.04 by running \"apt-get install --install-recommends linux-generic-hwe-16.04\""
     exit 1
@@ -158,7 +158,7 @@ done
 MEM_TOTAL=$(awk '/MemTotal/ {print $2}' /proc/meminfo)
 
 if [ -z "${SKIP_CLAMD}" ]; then
-  if [ ${MEM_TOTAL} -le "2621440" ]; then
+  if [ "${MEM_TOTAL}" -le "2621440" ]; then
     echo "Installed memory is <= 2.5 GiB. It is recommended to disable ClamAV to prevent out-of-memory situations."
     echo "ClamAV can be re-enabled by setting SKIP_CLAMD=n in mailcow.conf."
     read -r -p  "Do you want to disable ClamAV now? [Y/n] " response
@@ -176,10 +176,10 @@ if [ -z "${SKIP_CLAMD}" ]; then
 fi
 
 if [ -z "${SKIP_SOLR}" ]; then
-  if [ ${MEM_TOTAL} -le "2097152" ]; then
+  if [ "${MEM_TOTAL}" -le "2097152" ]; then
     echo "Disabling Solr on low-memory system."
     SKIP_SOLR=y
-  elif [ ${MEM_TOTAL} -le "3670016" ]; then
+  elif [ "${MEM_TOTAL}" -le "3670016" ]; then
     echo "Installed memory is <= 3.5 GiB. It is recommended to disable Solr to prevent out-of-memory situations."
     echo "Solr is a prone to run OOM and should be monitored. The default Solr heap size is 1024 MiB and should be set in mailcow.conf according to your expected load."
     echo "Solr can be re-enabled by setting SKIP_SOLR=n in mailcow.conf but will refuse to start with less than 2 GB total memory."
@@ -218,7 +218,7 @@ if [[ ${SKIP_BRANCH} != y ]]; then
   done
 
   git fetch --all
-  git checkout -f $MAILCOW_BRANCH
+  git checkout -f "$MAILCOW_BRANCH"
 
 elif [[ ${SKIP_BRANCH} == y ]]; then
   echo -e "\033[33mEnabled Dev Mode.\033[0m"

update.sh

@@ -22,13 +22,13 @@ prefetch_images() {
       fi
     fi
     RET_C=0
-    until docker pull ${image}; do
+    until docker pull "${image}"; do
       RET_C=$((RET_C + 1))
       echo -e "\e[33m\nError pulling $image, retrying...\e[0m"
       [ ${RET_C} -gt 3 ] && { echo -e "\e[31m\nToo many failed retries, exiting\e[0m"; exit 1; }
       sleep 1
     done
-  done < <(git show origin/${BRANCH}:docker-compose.yml | grep "image:" | awk '{ gsub("image:","", $3); print $2 }')
+  done < <(git show "origin/${BRANCH}:docker-compose.yml" | grep "image:" | awk '{ gsub("image:","", $3); print $2 }')
 }
 
 docker_garbage() {
@@ -39,9 +39,9 @@ docker_garbage() {
   COMPOSE_IMAGES=($(grep -oP "image: \Kmailcow.+" "${SCRIPT_DIR}/docker-compose.yml"))
 
   for existing_image in $(docker images --format "{{.ID}}:{{.Repository}}:{{.Tag}}" | grep 'mailcow/'); do
-      ID=$(echo $existing_image | cut -d ':' -f 1)
-      REPOSITORY=$(echo $existing_image | cut -d ':' -f 2)
-      TAG=$(echo $existing_image | cut -d ':' -f 3)
+      ID=$(echo "$existing_image" | cut -d ':' -f 1)
+      REPOSITORY=$(echo "$existing_image" | cut -d ':' -f 2)
+      TAG=$(echo "$existing_image" | cut -d ':' -f 3)
 
       if [[ " ${COMPOSE_IMAGES[@]} " =~ " ${REPOSITORY}:${TAG} " ]]; then
           continue
@@ -109,12 +109,12 @@ migrate_docker_nat() {
           echo -e "\e[33mWarning:\e[0m You seem to have modified the /etc/docker/daemon.json configuration by yourself and not fully/correctly activated the native IPv6 NAT implementation."
           echo "You will need to merge your existing configuration manually or fix/delete the existing daemon.json configuration before trying the update process again."
           echo -e "Please merge the following content and restart the Docker daemon:\n"
-          echo ${NAT_CONFIG}
+          echo "${NAT_CONFIG}"
           return 1
       fi
     else
       echo "Working on IPv6 NAT, please wait..."
-      echo ${NAT_CONFIG} > /etc/docker/daemon.json
+      echo "${NAT_CONFIG}" > /etc/docker/daemon.json
       ip6tables -F -t nat
       [[ -e /etc/rc.conf ]] && rc-service docker restart || systemctl restart docker.service
       if [[ $? -ne 0 ]]; then
@@ -165,7 +165,7 @@ remove_obsolete_nginx_ports() {
           fi
         fi
     fi
-    done        
+    done
 }
 
 detect_docker_compose_command(){
@@ -176,11 +176,11 @@ if ! [[ "${DOCKER_COMPOSE_VERSION}" =~ ^(native|standalone)$ ]]; then
         COMPOSE_COMMAND="docker compose"
         echo -e "\e[33mFound Docker Compose Plugin (native).\e[0m"
         echo -e "\e[33mSetting the DOCKER_COMPOSE_VERSION Variable to native\e[0m"
-        sed -i 's/^DOCKER_COMPOSE_VERSION=.*/DOCKER_COMPOSE_VERSION=native/' $SCRIPT_DIR/mailcow.conf 
+        sed -i 's/^DOCKER_COMPOSE_VERSION=.*/DOCKER_COMPOSE_VERSION=native/' "$SCRIPT_DIR/mailcow.conf"
         sleep 2
         echo -e "\e[33mNotice: You'll have to update this Compose Version via your Package Manager manually!\e[0m"
       else
-        echo -e "\e[31mCannot find Docker Compose with a Version Higher than 2.X.X.\e[0m" 
+        echo -e "\e[31mCannot find Docker Compose with a Version Higher than 2.X.X.\e[0m"
         echo -e "\e[31mPlease update/install it manually regarding to this doc site: https://docs.mailcow.email/install/\e[0m"
         exit 1
       fi
@@ -191,58 +191,58 @@ if ! [[ "${DOCKER_COMPOSE_VERSION}" =~ ^(native|standalone)$ ]]; then
         COMPOSE_COMMAND="docker-compose"
         echo -e "\e[33mFound Docker Compose Standalone.\e[0m"
         echo -e "\e[33mSetting the DOCKER_COMPOSE_VERSION Variable to standalone\e[0m"
-        sed -i 's/^DOCKER_COMPOSE_VERSION=.*/DOCKER_COMPOSE_VERSION=standalone/' $SCRIPT_DIR/mailcow.conf
+        sed -i 's/^DOCKER_COMPOSE_VERSION=.*/DOCKER_COMPOSE_VERSION=standalone/' "$SCRIPT_DIR/mailcow.conf"
         sleep 2
         echo -e "\e[33mNotice: For an automatic update of docker-compose please use the update_compose.sh scripts located at the helper-scripts folder.\e[0m"
       else
-        echo -e "\e[31mCannot find Docker Compose with a Version Higher than 2.X.X.\e[0m" 
+        echo -e "\e[31mCannot find Docker Compose with a Version Higher than 2.X.X.\e[0m"
         echo -e "\e[31mPlease update/install regarding to this doc site: https://docs.mailcow.email/install/\e[0m"
         exit 1
       fi
     fi
 
   else
-    echo -e "\e[31mCannot find Docker Compose.\e[0m" 
+    echo -e "\e[31mCannot find Docker Compose.\e[0m"
     echo -e "\e[31mPlease install it regarding to this doc site: https://docs.mailcow.email/install/\e[0m"
     exit 1
   fi
 
 elif [ "${DOCKER_COMPOSE_VERSION}" == "native" ]; then
   COMPOSE_COMMAND="docker compose"
-  # Check if Native Compose works and has not been deleted  
+  # Check if Native Compose works and has not been deleted
   if ! $COMPOSE_COMMAND > /dev/null 2>&1; then
     # IF it not exists/work anymore try the other command
     COMPOSE_COMMAND="docker-compose"
     if ! $COMPOSE_COMMAND > /dev/null 2>&1 || ! $COMPOSE_COMMAND --version | grep "^2." > /dev/null 2>&1; then
       # IF it cannot find Standalone in > 2.X, then script stops
-      echo -e "\e[31mCannot find Docker Compose or the Version is lower then 2.X.X.\e[0m" 
+      echo -e "\e[31mCannot find Docker Compose or the Version is lower then 2.X.X.\e[0m"
       echo -e "\e[31mPlease install it regarding to this doc site: https://docs.mailcow.email/install/\e[0m"
       exit 1
     fi
       # If it finds the standalone Plugin it will use this instead and change the mailcow.conf Variable accordingly
       echo -e "\e[31mFound different Docker Compose Version then declared in mailcow.conf!\e[0m"
       echo -e "\e[31mSetting the DOCKER_COMPOSE_VERSION Variable from native to standalone\e[0m"
-      sed -i 's/^DOCKER_COMPOSE_VERSION=.*/DOCKER_COMPOSE_VERSION=standalone/' $SCRIPT_DIR/mailcow.conf 
+      sed -i 's/^DOCKER_COMPOSE_VERSION=.*/DOCKER_COMPOSE_VERSION=standalone/' "$SCRIPT_DIR/mailcow.conf"
       sleep 2
   fi
 
 
 elif [ "${DOCKER_COMPOSE_VERSION}" == "standalone" ]; then
   COMPOSE_COMMAND="docker-compose"
-  # Check if Standalone Compose works and has not been deleted  
+  # Check if Standalone Compose works and has not been deleted
   if ! $COMPOSE_COMMAND > /dev/null 2>&1 && ! $COMPOSE_COMMAND --version > /dev/null 2>&1 | grep "^2." > /dev/null 2>&1; then
     # IF it not exists/work anymore try the other command
     COMPOSE_COMMAND="docker compose"
     if ! $COMPOSE_COMMAND > /dev/null 2>&1; then
       # IF it cannot find Native in > 2.X, then script stops
-      echo -e "\e[31mCannot find Docker Compose.\e[0m" 
+      echo -e "\e[31mCannot find Docker Compose.\e[0m"
       echo -e "\e[31mPlease install it regarding to this doc site: https://docs.mailcow.email/install/\e[0m"
       exit 1
     fi
       # If it finds the native Plugin it will use this instead and change the mailcow.conf Variable accordingly
       echo -e "\e[31mFound different Docker Compose Version then declared in mailcow.conf!\e[0m"
       echo -e "\e[31mSetting the DOCKER_COMPOSE_VERSION Variable from standalone to native\e[0m"
-      sed -i 's/^DOCKER_COMPOSE_VERSION=.*/DOCKER_COMPOSE_VERSION=native/' $SCRIPT_DIR/mailcow.conf 
+      sed -i 's/^DOCKER_COMPOSE_VERSION=.*/DOCKER_COMPOSE_VERSION=native/' "$SCRIPT_DIR/mailcow.conf"
       sleep 2
   fi
 fi
@@ -297,7 +297,7 @@ if [[ "$(uname -r)" =~ ^4\.15\.0-60 ]]; then
 fi
 
 if [[ "$(uname -r)" =~ ^4\.4\. ]]; then
-  if grep -q Ubuntu <<< $(uname -a); then
+  if grep -q Ubuntu <<< "$(uname -a)"; then
     echo "DO NOT RUN mailcow ON THIS UBUNTU KERNEL!"
     echo "Please update to linux-generic-hwe-16.04 by running \"apt-get install --install-recommends linux-generic-hwe-16.04\""
     exit 1
@@ -322,10 +322,10 @@ unset COMPOSE_COMMAND
 unset DOCKER_COMPOSE_VERSION
 
 for bin in curl docker git awk sha1sum grep cut; do
-  if [[ -z $(command -v ${bin}) ]]; then 
-  echo "Cannot find ${bin}, exiting..." 
+  if [[ -z $(command -v ${bin}) ]]; then
+  echo "Cannot find ${bin}, exiting..."
   exit 1;
-  fi  
+  fi
 done
 
 # Check Docker Version (need at least 24.X)
@@ -340,20 +340,20 @@ fi
 
 export LC_ALL=C
 DATE=$(date +%Y-%m-%d_%H_%M_%S)
-BRANCH=$(cd ${SCRIPT_DIR}; git rev-parse --abbrev-ref HEAD)
+BRANCH="$(cd "${SCRIPT_DIR}"; git rev-parse --abbrev-ref HEAD)"
 
 while (($#)); do
   case "${1}" in
     --check|-c)
       echo "Checking remote code for updates..."
-      LATEST_REV=$(git ls-remote --exit-code --refs --quiet https://github.com/mailcow/mailcow-dockerized ${BRANCH} | cut -f1)
-      if [ $? -ne 0 ]; then
+      LATEST_REV=$(git ls-remote --exit-code --refs --quiet https://github.com/mailcow/mailcow-dockerized "${BRANCH}" | cut -f1)
+      if [ "$?" -ne 0 ]; then
         echo "A problem occurred while trying to fetch the latest revision from github."
         exit 99
       fi
       if [[ -z $(git log HEAD --pretty=format:"%H" | grep "${LATEST_REV}") ]]; then
         echo -e "Updated code is available.\nThe changes can be found here: https://github.com/mailcow/mailcow-dockerized/commits/master"
-        git log --date=short --pretty=format:"%ad - %s" $(git rev-parse --short HEAD)..origin/master
+        git log --date=short --pretty=format:"%ad - %s" "$(git rev-parse --short HEAD)"..origin/master
         exit 0
       else
         echo "No updates available."
@@ -370,7 +370,7 @@ while (($#)); do
       SKIP_PING_CHECK=y
     ;;
     --stable)
-      CURRENT_BRANCH="$(cd ${SCRIPT_DIR}; git rev-parse --abbrev-ref HEAD)"
+      CURRENT_BRANCH="$(cd "${SCRIPT_DIR}"; git rev-parse --abbrev-ref HEAD)"
       NEW_BRANCH="master"
     ;;
     --gc)
@@ -379,7 +379,7 @@ while (($#)); do
       exit 0
     ;;
     --nightly)
-      CURRENT_BRANCH="$(cd ${SCRIPT_DIR}; git rev-parse --abbrev-ref HEAD)"
+      CURRENT_BRANCH="$(cd "${SCRIPT_DIR}"; git rev-parse --abbrev-ref HEAD)"
       NEW_BRANCH="nightly"
     ;;
     --prefetch)
@@ -499,19 +499,19 @@ CONFIG_ARRAY=(
 detect_bad_asn
 
 sed -i --follow-symlinks '$a\' mailcow.conf
-for option in ${CONFIG_ARRAY[@]}; do
+for option in "${CONFIG_ARRAY[@]}"; do
   if [[ ${option} == "ADDITIONAL_SAN" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo "${option}=" >> mailcow.conf
     fi
-  elif [[ ${option} == "COMPOSE_PROJECT_NAME" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "COMPOSE_PROJECT_NAME" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo "COMPOSE_PROJECT_NAME=mailcowdockerized" >> mailcow.conf
     fi
-  elif [[ ${option} == "DOCKER_COMPOSE_VERSION" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "DOCKER_COMPOSE_VERSION" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo "# Used Docker Compose version" >> mailcow.conf
       echo "# Switch here between native (compose plugin) and standalone" >> mailcow.conf
@@ -521,73 +521,73 @@ for option in ${CONFIG_ARRAY[@]}; do
       echo "" >> mailcow.conf
       echo "DOCKER_COMPOSE_VERSION=${DOCKER_COMPOSE_VERSION}" >> mailcow.conf
     fi
-  elif [[ ${option} == "DOVEADM_PORT" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "DOVEADM_PORT" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo "DOVEADM_PORT=127.0.0.1:19991" >> mailcow.conf
     fi
-  elif [[ ${option} == "WATCHDOG_NOTIFY_EMAIL" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WATCHDOG_NOTIFY_EMAIL" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo "WATCHDOG_NOTIFY_EMAIL=" >> mailcow.conf
     fi
-  elif [[ ${option} == "LOG_LINES" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "LOG_LINES" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Max log lines per service to keep in Redis logs' >> mailcow.conf
       echo "LOG_LINES=9999" >> mailcow.conf
     fi
-  elif [[ ${option} == "IPV4_NETWORK" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "IPV4_NETWORK" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Internal IPv4 /24 subnet, format n.n.n. (expands to n.n.n.0/24)' >> mailcow.conf
       echo "IPV4_NETWORK=172.22.1" >> mailcow.conf
     fi
-  elif [[ ${option} == "IPV6_NETWORK" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "IPV6_NETWORK" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Internal IPv6 subnet in fc00::/7' >> mailcow.conf
       echo "IPV6_NETWORK=fd4d:6169:6c63:6f77::/64" >> mailcow.conf
     fi
-  elif [[ ${option} == "SQL_PORT" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SQL_PORT" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Bind SQL to 127.0.0.1 on port 13306' >> mailcow.conf
       echo "SQL_PORT=127.0.0.1:13306" >> mailcow.conf
     fi
-  elif [[ ${option} == "API_KEY" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "API_KEY" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Create or override API key for web UI' >> mailcow.conf
       echo "#API_KEY=" >> mailcow.conf
     fi
-  elif [[ ${option} == "API_KEY_READ_ONLY" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "API_KEY_READ_ONLY" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Create or override read-only API key for web UI' >> mailcow.conf
       echo "#API_KEY_READ_ONLY=" >> mailcow.conf
     fi
-  elif [[ ${option} == "API_ALLOW_FROM" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "API_ALLOW_FROM" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Must be set for API_KEY to be active' >> mailcow.conf
       echo '# IPs only, no networks (networks can be set via UI)' >> mailcow.conf
       echo "#API_ALLOW_FROM=" >> mailcow.conf
     fi
-  elif [[ ${option} == "SNAT_TO_SOURCE" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SNAT_TO_SOURCE" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Use this IPv4 for outgoing connections (SNAT)' >> mailcow.conf
       echo "#SNAT_TO_SOURCE=" >> mailcow.conf
     fi
-  elif [[ ${option} == "SNAT6_TO_SOURCE" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SNAT6_TO_SOURCE" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Use this IPv6 for outgoing connections (SNAT)' >> mailcow.conf
       echo "#SNAT6_TO_SOURCE=" >> mailcow.conf
     fi
-  elif [[ ${option} == "MAILDIR_GC_TIME" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "MAILDIR_GC_TIME" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Garbage collector cleanup' >> mailcow.conf
       echo '# Deleted domains and mailboxes are moved to /var/vmail/_garbage/timestamp_sanitizedstring' >> mailcow.conf
@@ -595,8 +595,8 @@ for option in ${CONFIG_ARRAY[@]}; do
       echo '# Check interval is hourly' >> mailcow.conf
       echo 'MAILDIR_GC_TIME=1440' >> mailcow.conf
     fi
-  elif [[ ${option} == "ACL_ANYONE" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "ACL_ANYONE" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Set this to "allow" to enable the anyone pseudo user. Disabled by default.' >> mailcow.conf
       echo '# When enabled, ACL can be created, that apply to "All authenticated users"' >> mailcow.conf
@@ -604,96 +604,96 @@ for option in ${CONFIG_ARRAY[@]}; do
       echo '# Otherwise a user might share data with too many other users.' >> mailcow.conf
       echo 'ACL_ANYONE=disallow' >> mailcow.conf
     fi
-  elif [[ ${option} == "SOLR_HEAP" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SOLR_HEAP" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Solr heap size, there is no recommendation, please see Solr docs.' >> mailcow.conf
       echo '# Solr is a prone to run OOM on large systems and should be monitored. Unmonitored Solr setups are not recommended.' >> mailcow.conf
       echo '# Solr will refuse to start with total system memory below or equal to 2 GB.' >> mailcow.conf
       echo "SOLR_HEAP=1024" >> mailcow.conf
     fi
-  elif [[ ${option} == "SKIP_SOLR" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SKIP_SOLR" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Solr is disabled by default after upgrading from non-Solr to Solr-enabled mailcows.' >> mailcow.conf
       echo '# Disable Solr or if you do not want to store a readable index of your mails in solr-vol-1.' >> mailcow.conf
       echo "SKIP_SOLR=y" >> mailcow.conf
     fi
-  elif [[ ${option} == "ENABLE_SSL_SNI" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "ENABLE_SSL_SNI" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Create seperate certificates for all domains - y/n' >> mailcow.conf
       echo '# this will allow adding more than 100 domains, but some email clients will not be able to connect with alternative hostnames' >> mailcow.conf
       echo '# see https://wiki.dovecot.org/SSL/SNIClientSupport' >> mailcow.conf
       echo "ENABLE_SSL_SNI=n" >> mailcow.conf
     fi
-  elif [[ ${option} == "SKIP_SOGO" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SKIP_SOGO" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Skip SOGo: Will disable SOGo integration and therefore webmail, DAV protocols and ActiveSync support (experimental, unsupported, not fully implemented) - y/n' >> mailcow.conf
       echo "SKIP_SOGO=n" >> mailcow.conf
     fi
-  elif [[ ${option} == "MAILDIR_SUB" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "MAILDIR_SUB" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# MAILDIR_SUB defines a path in a users virtual home to keep the maildir in. Leave empty for updated setups.' >> mailcow.conf
       echo "#MAILDIR_SUB=Maildir" >> mailcow.conf
       echo "MAILDIR_SUB=" >> mailcow.conf
     fi
-  elif [[ ${option} == "WATCHDOG_NOTIFY_WEBHOOK" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WATCHDOG_NOTIFY_WEBHOOK" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Send notifications to a webhook URL that receives a POST request with the content type "application/json".' >> mailcow.conf
       echo '# You can use this to send notifications to services like Discord, Slack and others.' >> mailcow.conf
       echo '#WATCHDOG_NOTIFY_WEBHOOK=https://discord.com/api/webhooks/XXXXXXXXXXXXXXXXXXX/XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' >> mailcow.conf
     fi
-  elif [[ ${option} == "WATCHDOG_NOTIFY_WEBHOOK_BODY" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WATCHDOG_NOTIFY_WEBHOOK_BODY" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# JSON body included in the webhook POST request. Needs to be in single quotes.' >> mailcow.conf
       echo '# Following variables are available: SUBJECT, BODY' >> mailcow.conf
       WEBHOOK_BODY='{"username": "mailcow Watchdog", "content": "**${SUBJECT}**\n${BODY}"}'
       echo "#WATCHDOG_NOTIFY_WEBHOOK_BODY='${WEBHOOK_BODY}'" >> mailcow.conf
     fi
-  elif [[ ${option} == "WATCHDOG_NOTIFY_BAN" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WATCHDOG_NOTIFY_BAN" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Notify about banned IP. Includes whois lookup.' >> mailcow.conf
       echo "WATCHDOG_NOTIFY_BAN=y" >> mailcow.conf
     fi
-  elif [[ ${option} == "WATCHDOG_NOTIFY_START" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WATCHDOG_NOTIFY_START" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Send a notification when the watchdog is started.' >> mailcow.conf
       echo "WATCHDOG_NOTIFY_START=y" >> mailcow.conf
     fi
-  elif [[ ${option} == "WATCHDOG_SUBJECT" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WATCHDOG_SUBJECT" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Subject for watchdog mails. Defaults to "Watchdog ALERT" followed by the error message.' >> mailcow.conf
       echo "#WATCHDOG_SUBJECT=" >> mailcow.conf
     fi
-  elif [[ ${option} == "WATCHDOG_EXTERNAL_CHECKS" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WATCHDOG_EXTERNAL_CHECKS" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Checks if mailcow is an open relay. Requires a SAL. More checks will follow.' >> mailcow.conf
       echo '# No data is collected. Opt-in and anonymous.' >> mailcow.conf
       echo '# Will only work with unmodified mailcow setups.' >> mailcow.conf
       echo "WATCHDOG_EXTERNAL_CHECKS=n" >> mailcow.conf
     fi
-  elif [[ ${option} == "SOGO_EXPIRE_SESSION" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SOGO_EXPIRE_SESSION" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# SOGo session timeout in minutes' >> mailcow.conf
       echo "SOGO_EXPIRE_SESSION=480" >> mailcow.conf
     fi
-  elif [[ ${option} == "REDIS_PORT" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "REDIS_PORT" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo "REDIS_PORT=127.0.0.1:7654" >> mailcow.conf
     fi
-  elif [[ ${option} == "DOVECOT_MASTER_USER" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "DOVECOT_MASTER_USER" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# DOVECOT_MASTER_USER and _PASS must _both_ be provided. No special chars.' >> mailcow.conf
       echo '# Empty by default to auto-generate master user and password on start.' >> mailcow.conf
@@ -701,22 +701,22 @@ for option in ${CONFIG_ARRAY[@]}; do
       echo '# LEAVE EMPTY IF UNSURE' >> mailcow.conf
       echo "DOVECOT_MASTER_USER=" >> mailcow.conf
     fi
-  elif [[ ${option} == "DOVECOT_MASTER_PASS" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "DOVECOT_MASTER_PASS" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# LEAVE EMPTY IF UNSURE' >> mailcow.conf
       echo "DOVECOT_MASTER_PASS=" >> mailcow.conf
     fi
-  elif [[ ${option} == "MAILCOW_PASS_SCHEME" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "MAILCOW_PASS_SCHEME" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Password hash algorithm' >> mailcow.conf
       echo '# Only certain password hash algorithm are supported. For a fully list of supported schemes,' >> mailcow.conf
       echo '# see https://docs.mailcow.email/models/model-passwd/' >> mailcow.conf
       echo "MAILCOW_PASS_SCHEME=BLF-CRYPT" >> mailcow.conf
     fi
-  elif [[ ${option} == "ADDITIONAL_SERVER_NAMES" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "ADDITIONAL_SERVER_NAMES" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Additional server names for mailcow UI' >> mailcow.conf
       echo '#' >> mailcow.conf
@@ -728,8 +728,8 @@ for option in ${CONFIG_ARRAY[@]}; do
       echo 'ADDITIONAL_SERVER_NAMES=' >> mailcow.conf
     fi
 
-  elif [[ ${option} == "AUTODISCOVER_SAN" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "AUTODISCOVER_SAN" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Obtain certificates for autodiscover.* and autoconfig.* domains.' >> mailcow.conf
       echo '# This can be useful to switch off in case you are in a scenario where a reverse proxy already handles those.' >> mailcow.conf
@@ -739,8 +739,8 @@ for option in ${CONFIG_ARRAY[@]}; do
       echo 'AUTODISCOVER_SAN=y' >> mailcow.conf
     fi
 
-  elif [[ ${option} == "ACME_CONTACT" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "ACME_CONTACT" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Lets Encrypt registration contact information' >> mailcow.conf
       echo '# Optional: Leave empty for none' >> mailcow.conf
@@ -749,16 +749,16 @@ for option in ${CONFIG_ARRAY[@]}; do
       echo '# https://docs.mailcow.email/troubleshooting/debug-reset_tls/' >> mailcow.conf
       echo 'ACME_CONTACT=' >> mailcow.conf
     fi
-  elif [[ ${option} == "WEBAUTHN_ONLY_TRUSTED_VENDORS" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WEBAUTHN_ONLY_TRUSTED_VENDORS" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo "# WebAuthn device manufacturer verification" >> mailcow.conf
       echo '# After setting WEBAUTHN_ONLY_TRUSTED_VENDORS=y only devices from trusted manufacturers are allowed' >> mailcow.conf
       echo '# root certificates can be placed for validation under mailcow-dockerized/data/web/inc/lib/WebAuthn/rootCertificates' >> mailcow.conf
       echo 'WEBAUTHN_ONLY_TRUSTED_VENDORS=n' >> mailcow.conf
     fi
-  elif [[ ${option} == "SPAMHAUS_DQS_KEY" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SPAMHAUS_DQS_KEY" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo "# Spamhaus Data Query Service Key" >> mailcow.conf
       echo '# Optional: Leave empty for none' >> mailcow.conf
@@ -767,32 +767,32 @@ for option in ${CONFIG_ARRAY[@]}; do
       echo '# Otherwise it will work as usual.' >> mailcow.conf
       echo 'SPAMHAUS_DQS_KEY=' >> mailcow.conf
     fi
-  elif [[ ${option} == "WATCHDOG_VERBOSE" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "WATCHDOG_VERBOSE" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Enable watchdog verbose logging' >> mailcow.conf
       echo 'WATCHDOG_VERBOSE=n' >> mailcow.conf
     fi
-  elif [[ ${option} == "SKIP_UNBOUND_HEALTHCHECK" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "SKIP_UNBOUND_HEALTHCHECK" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Skip Unbound (DNS Resolver) Healthchecks (NOT Recommended!) - y/n' >> mailcow.conf
       echo 'SKIP_UNBOUND_HEALTHCHECK=n' >> mailcow.conf
     fi
-  elif [[ ${option} == "DISABLE_NETFILTER_ISOLATION_RULE" ]]; then
-    if ! grep -q ${option} mailcow.conf; then
+  elif [[ "${option}" == "DISABLE_NETFILTER_ISOLATION_RULE" ]]; then
+    if ! grep -q "${option}" mailcow.conf; then
       echo "Adding new option \"${option}\" to mailcow.conf"
       echo '# Prevent netfilter from setting an iptables/nftables rule to isolate the mailcow docker network - y/n' >> mailcow.conf
       echo '# CAUTION: Disabling this may expose container ports to other neighbors on the same subnet, even if the ports are bound to localhost' >> mailcow.conf
       echo 'DISABLE_NETFILTER_ISOLATION_RULE=n' >> mailcow.conf
-    fi 
-  elif ! grep -q ${option} mailcow.conf; then
+    fi
+  elif ! grep -q "${option}" mailcow.conf; then
     echo "Adding new option \"${option}\" to mailcow.conf"
     echo "${option}=n" >> mailcow.conf
   fi
 done
 
-if [[( ${SKIP_PING_CHECK} == "y")]]; then
+if [[ ("${SKIP_PING_CHECK}" == "y") ]]; then
 echo -e "\e[32mSkipping Ping Check...\e[0m"
 
 else
@@ -805,14 +805,14 @@ else
    fi
 fi
 
-if ! [ $NEW_BRANCH ]; then
+if ! [ "$NEW_BRANCH" ]; then
   echo -e "\e[33mDetecting which build your mailcow runs on...\e[0m"
   sleep 1
-  if [ ${BRANCH} == "master" ]; then
+  if [ "${BRANCH}" == "master" ]; then
     echo -e "\e[32mYou are receiving stable updates (master).\e[0m"
     echo -e "\e[33mTo change that run the update.sh Script one time with the --nightly parameter to switch to nightly builds.\e[0m"
 
-  elif [ ${BRANCH} == "nightly" ]; then
+  elif [ "${BRANCH}" == "nightly" ]; then
     echo -e "\e[31mYou are receiving unstable updates (nightly). These are for testing purposes only!!!\e[0m"
     sleep 1
     echo -e "\e[33mTo change that run the update.sh Script one time with the --stable parameter to switch to stable builds.\e[0m"
@@ -823,12 +823,12 @@ if ! [ $NEW_BRANCH ]; then
     echo -e "\e[33mThe mailcow stack might still work but it is recommended to switch to the master branch (stable builds).\e[0m"
     echo -e "\e[33mTo change that run the update.sh Script one time with the --stable parameter to switch to stable builds.\e[0m"
   fi
-elif [ $FORCE ]; then
+elif [ "$FORCE" ]; then
   echo -e "\e[31mYou are running in forced mode!\e[0m"
   echo -e "\e[31mA Branch Switch can only be performed manually (monitored).\e[0m"
   echo -e "\e[31mPlease rerun the update.sh Script without the --force/-f parameter.\e[0m"
   sleep 1
-elif [ $NEW_BRANCH == "master" ] && [ $CURRENT_BRANCH != "master" ]; then
+elif [ "$NEW_BRANCH" == "master" ] && [ "$CURRENT_BRANCH" != "master" ]; then
   echo -e "\e[33mYou are about to switch your mailcow updates to the stable (master) branch.\e[0m"
   sleep 1
   echo -e "\e[33mBefore you do: Please take a backup of all components to ensure that no data is lost...\e[0m"
@@ -842,21 +842,21 @@ elif [ $NEW_BRANCH == "master" ] && [ $CURRENT_BRANCH != "master" ]; then
     echo "OK. If you prepared yourself for that please run the update.sh Script with the --stable parameter again to trigger this process here."
     exit 0
   fi
-  BRANCH=$NEW_BRANCH
+  BRANCH="$NEW_BRANCH"
   DIFF_DIRECTORY=update_diffs
-  DIFF_FILE=${DIFF_DIRECTORY}/diff_before_upgrade_to_master_$(date +"%Y-%m-%d-%H-%M-%S")
-  mv diff_before_upgrade* ${DIFF_DIRECTORY}/ 2> /dev/null
+  DIFF_FILE="${DIFF_DIRECTORY}/diff_before_upgrade_to_master_$(date +"%Y-%m-%d-%H-%M-%S")"
+  mv diff_before_upgrade* "${DIFF_DIRECTORY}/" 2> /dev/null
   if ! git diff-index --quiet HEAD; then
     echo -e "\e[32mSaving diff to ${DIFF_FILE}...\e[0m"
-    mkdir -p ${DIFF_DIRECTORY}
-    git diff ${BRANCH} --stat > ${DIFF_FILE}
-    git diff ${BRANCH} >> ${DIFF_FILE}
+    mkdir -p "${DIFF_DIRECTORY}"
+    git diff "${BRANCH}" --stat > "${DIFF_FILE}"
+    git diff "${BRANCH}" >> "${DIFF_FILE}"
   fi
   echo -e "\e[32mSwitching Branch to ${BRANCH}...\e[0m"
   git fetch origin
-  git checkout -f ${BRANCH}
+  git checkout -f "${BRANCH}"
 
-elif [ $NEW_BRANCH == "nightly" ] && [ $CURRENT_BRANCH != "nightly" ]; then
+elif [ "$NEW_BRANCH" == "nightly" ] && [ "$CURRENT_BRANCH" != "nightly" ]; then
   echo -e "\e[33mYou are about to switch your mailcow Updates to the unstable (nightly) branch.\e[0m"
   sleep 1
   echo -e "\e[33mBefore you do: Please take a backup of all components to ensure that no Data is lost...\e[0m"
@@ -874,27 +874,27 @@ elif [ $NEW_BRANCH == "nightly" ] && [ $CURRENT_BRANCH != "nightly" ]; then
   if ! git diff-index --quiet HEAD; then
     echo -e "\e[32mSaving diff to ${DIFF_FILE}...\e[0m"
     mkdir -p ${DIFF_DIRECTORY}
-    git diff ${BRANCH} --stat > ${DIFF_FILE}
-    git diff ${BRANCH} >> ${DIFF_FILE}
+    git diff "${BRANCH}" --stat > "${DIFF_FILE}"
+    git diff "${BRANCH}" >> "${DIFF_FILE}"
   fi
   git fetch origin
-  git checkout -f ${BRANCH}
+  git checkout -f "${BRANCH}"
 fi
 
-if [ ! $DEV ]; then
+if [ ! "$DEV" ]; then
   echo -e "\e[32mChecking for newer update script...\e[0m"
-  SHA1_1=$(sha1sum update.sh)
+  SHA1_1="$(sha1sum update.sh)"
   git fetch origin #${BRANCH}
-  git checkout origin/${BRANCH} update.sh
+  git checkout "origin/${BRANCH}" update.sh
   SHA1_2=$(sha1sum update.sh)
-  if [[ ${SHA1_1} != ${SHA1_2} ]]; then
+  if [[ "${SHA1_1}" != "${SHA1_2}" ]]; then
     echo "update.sh changed, please run this script again, exiting."
     chmod +x update.sh
     exit 2
   fi
 fi
 
-if [ ! $FORCE ]; then
+if [ ! "$FORCE" ]; then
   read -r -p "Are you sure you want to update mailcow: dockerized? All containers will be stopped. [y/N] " response
   if [[ ! "${response}" =~ ^([yY][eE][sS]|[yY])+$ ]]; then
     echo "OK, exiting."
@@ -916,8 +916,8 @@ fi
 echo -e "\e[32mChecking for conflicting bridges...\e[0m"
 MAILCOW_BRIDGE=$($COMPOSE_COMMAND config | grep -i com.docker.network.bridge.name | cut -d':' -f2)
 while read NAT_ID; do
-  iptables -t nat -D POSTROUTING $NAT_ID
-done < <(iptables -L -vn -t nat --line-numbers | grep $IPV4_NETWORK | grep -E 'MASQUERADE.*all' | grep -v ${MAILCOW_BRIDGE} | cut -d' ' -f1)
+  iptables -t nat -D POSTROUTING "$NAT_ID"
+done < <(iptables -L -vn -t nat --line-numbers | grep "$IPV4_NETWORK" | grep -E 'MASQUERADE.*all' | grep -v "${MAILCOW_BRIDGE}" | cut -d' ' -f1)
 
 DIFF_DIRECTORY=update_diffs
 DIFF_FILE=${DIFF_DIRECTORY}/diff_before_update_$(date +"%Y-%m-%d-%H-%M-%S")
@@ -925,8 +925,8 @@ mv diff_before_update* ${DIFF_DIRECTORY}/ 2> /dev/null
 if ! git diff-index --quiet HEAD; then
   echo -e "\e[32mSaving diff to ${DIFF_FILE}...\e[0m"
   mkdir -p ${DIFF_DIRECTORY}
-  git diff --stat > ${DIFF_FILE}
-  git diff >> ${DIFF_FILE}
+  git diff --stat > "${DIFF_FILE}"
+  git diff >> "${DIFF_FILE}"
 fi
 
 echo -e "\e[32mPrefetching images...\e[0m"
@@ -948,13 +948,13 @@ done
 # Silently fixing remote url from andryyy to mailcow
 # git remote set-url origin https://github.com/mailcow/mailcow-dockerized
 
-DEFAULT_REPO=https://github.com/mailcow/mailcow-dockerized
+DEFAULT_REPO="https://github.com/mailcow/mailcow-dockerized"
 CURRENT_REPO=$(git config --get remote.origin.url)
-if [ "$CURRENT_REPO" != "$DEFAULT_REPO" ]; then 
+if [ "$CURRENT_REPO" != "$DEFAULT_REPO" ]; then
   echo "The Repository currently used is not the default Mailcow Repository."
   echo "Currently Repository: $CURRENT_REPO"
   echo "Default Repository:   $DEFAULT_REPO"
-  if [ ! $FORCE ]; then
+  if [ ! "$FORCE" ]; then
     read -r -p "Should it be changed back to default? [y/N] " repo_response
     if [[ "$repo_response" =~ ^([yY][eE][sS]|[yY])+$ ]]; then
       git remote set-url origin $DEFAULT_REPO
@@ -965,7 +965,7 @@ if [ "$CURRENT_REPO" != "$DEFAULT_REPO" ]; then
   fi
 fi
 
-if [ ! $DEV ]; then
+if [ ! "$DEV" ]; then
   echo -e "\e[32mCommitting current status...\e[0m"
   [[ -z "$(git config user.name)" ]] && git config user.name moo
   [[ -z "$(git config user.email)" ]] && git config user.email moo@cow.moo
@@ -976,7 +976,7 @@ if [ ! $DEV ]; then
   git fetch origin #${BRANCH}
   echo -e "\e[32mMerging local with remote code (recursive, strategy: \"${MERGE_STRATEGY:-theirs}\", options: \"patience\"...\e[0m"
   git config merge.defaultToUpstream true
-  git merge -X${MERGE_STRATEGY:-theirs} -Xpatience -m "After update on ${DATE}"
+  git merge -X"${MERGE_STRATEGY:-theirs}" -Xpatience -m "After update on ${DATE}"
   # Need to use a variable to not pass return codes of if checks
   MERGE_RETURN=$?
   if [[ ${MERGE_RETURN} == 128 ]]; then
@@ -995,7 +995,7 @@ if [ ! $DEV ]; then
     echo "Run $COMPOSE_COMMAND up -d to restart your stack without updates or try again after fixing the mentioned errors."
     exit 1
   fi
-elif [ $DEV ]; then
+elif [ "$DEV" ]; then
   echo -e "\e[33mDEVELOPER MODE: Not creating a git diff and commiting it to prevent development stuff within a backup diff...\e[0m"
 fi
 
@@ -1042,7 +1042,7 @@ fi
 
 # Set app_info.inc.php
 if [ ${BRANCH} == "master" ]; then
-  mailcow_git_version=$(git describe --tags `git rev-list --tags --max-count=1`)
+  mailcow_git_version=$(git describe --tags $(git rev-list --tags --max-count=1))
 elif [ ${BRANCH} == "nightly" ]; then
   mailcow_git_version=$(git rev-parse --short $(git rev-parse @{upstream}))
   mailcow_last_git_version=""
@@ -1051,7 +1051,7 @@ else
   mailcow_last_git_version=""
 fi
 
-mailcow_git_commit=$(git rev-parse origin/${BRANCH})
+mailcow_git_commit=$(git rev-parse "origin/${BRANCH}")
 mailcow_git_commit_date=$(git log -1 --format=%ci @{upstream} )
 
 if [ $? -eq 0 ]; then