diff --git a/uprgade-keycloak.sh b/uprgade-keycloak.sh
new file mode 100755
index 0000000..2804185
--- /dev/null
+++ b/uprgade-keycloak.sh
@@ -0,0 +1,848 @@
+#!/usr/bin/env bash
+
+script_name="$(basename $(realpath $0))"
+working_dir="$(dirname $(realpath $0))"
+
+#conf_file="${working_dir}/conf/${script_name%%.*}.conf"
+conf_file="${working_dir}/conf/keycloak.conf"
+
+LOCK_DIR="/tmp/$(basename $0).$$.LOCK"
+log_file="${LOCK_DIR}/${script_name%%.*}.log"
+
+backup_date="$(date +%Y-%m-%d-%H%M)"
+
+crontab_backup_file="${working_dir}/crontab-root-${backup_date}"
+
+
+# ----------
+# Base Function(s)
+# ----------
+
+clean_up() {
+
+   # Perform program exit housekeeping
+   rm -rf "$LOCK_DIR"
+   blank_line
+   exit $1
+}
+
+echononl(){
+   if $terminal ; then
+      echo X\\c > /tmp/shprompt$$
+      if [ `wc -c /tmp/shprompt$$ | awk '{print $1}'` -eq 1 ]; then
+         echo -e -n "   $*\\c" 1>&2
+      else
+         echo -e -n "   $*" 1>&2
+      fi
+      rm /tmp/shprompt$$
+   fi
+}
+
+fatal(){
+   if $terminal ; then
+      echo ""
+      echo -e "   [ \033[31m\033[1mFatal\033[m ] $*"
+      echo ""
+      echo -e "             \033[1mScript is canceled\033[m.."
+      echo ""
+   else
+      echo ""
+      echo -e "   [ Fatal ] $*"
+      echo ""
+      echo -e "             Script is canceled.."
+      echo ""
+   fi
+   if [[ -f "${crontab_backup_file}" ]]; then
+      echononl "Reenable previously saved crontab from '$(basename "${crontab_backup_file}")'.."
+      crontab ${crontab_backup_file} > /dev/null  2>&1
+      if [[ $? -eq 0 ]]; then
+         echo_ok
+         rm -f ${crontab_backup_file} > /dev/null  2>&11
+      else
+         echo_failed
+         error "$(cat $log_file)"
+      fi
+   fi
+
+   rm -rf $LOCK_DIR
+   exit 1
+}
+
+error (){
+   echo ""
+   if $terminal ; then
+      echo -e "   [ \033[31m\033[1mError\033[m ] $*"
+   else
+      echo "   [ Error ] $*"
+   fi
+   echo ""
+}
+
+warn (){
+   echo ""
+   if $terminal ; then
+      echo -e "   [ \033[33m\033[1mWarning\033[m ] $*"
+   else
+      echo "   [ Error ] $*"
+   fi
+   echo ""
+}
+
+info (){
+   if $terminal ; then
+      echo ""
+      if $terminal ; then
+         echo -e "   [ \033[32m\033[1mInfo\033[m ]  $*"
+      else
+         echo "   [ Info ]  $*"
+      fi
+      echo ""
+   fi
+}
+
+
+echo_ok() {
+   if $terminal ; then
+      echo -e "\033[85G[ \033[32mok\033[m ]"
+   fi
+}
+echo_failed(){
+   if $terminal ; then
+      echo -e "\033[85G[ \033[1;31mfailed\033[m ]"
+   fi
+}
+echo_skipped() {
+   if $terminal ; then
+      echo -e "\033[85G[ \033[33m\033[1mskipped\033[m ]"
+   fi
+}
+echo_wait(){
+   if $terminal ; then
+      echo -en "\033[85G[ \033[5m\033[1m..\033[m ]"
+   fi
+}
+
+trim() {
+    local var="$*"
+    var="${var#"${var%%[![:space:]]*}"}"   # remove leading whitespace characters
+    var="${var%"${var##*[![:space:]]}"}"   # remove trailing whitespace characters
+    echo -n "$var"
+}
+
+blank_line() {
+   if $terminal ; then
+      echo ""
+   fi
+}
+
+detect_os () {
+
+   if $(which lsb_release > /dev/null 2>&1) ; then
+
+      DIST="$(lsb_release -i | awk '{print tolower($3)}')"
+      DIST_VERSION="$(lsb_release -r | awk '{print tolower($2)}')"
+      DIST_CODENAME="$(lsb_release -c | awk '{print tolower($2)}')"
+
+      if [[ "$DIST" = "debian" ]]; then
+         if $(echo "$DIST_VERSION" | grep -q '\.') ; then
+            DIST_VERSION=$(echo "$DIST_VERSION" | cut --delimiter='.' -f1)
+         fi
+      fi
+
+   elif [[ -e "/etc/os-release" ]]; then
+
+      . /etc/os-release
+
+      DIST=$ID
+      DIST_VERSION=${VERSION_ID}
+
+   fi
+
+   # remove whitespace from DIST and DIST_VERSION
+   DIST="${DIST// /}"
+   DIST_VERSION="${DIST_VERSION// /}"
+
+}
+
+# Funktion zur Generierung eines zufälligen Zeichens aus einer gegebenen Zeichenmenge
+random_char() {
+    local chars="$1"
+    echo -n "${chars:RANDOM%${#chars}:1}"
+}
+
+# Funktion zur Generierung eines zufälligen Strings mit den angegebenen Anforderungen
+generate_random_string() {
+    local length="$1"
+
+    # Überprüfen, ob die Länge größer als 8 ist
+    if [[ "$length" -le 8 ]]; then
+        echo "Fehler: Die Länge muss größer als 8 Zeichen sein."
+        return 1
+    fi
+
+    # Zeichenmengen
+    local lower="abcdefghijklmnopqrstuvwxyz"
+    local upper="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    local digits="0123456789"
+    #local special="!@#$%^&*()_+-=[]{}|;:,.<>?/"
+    local special="_+--//...."
+
+    # Generiere mindestens ein Zeichen aus jeder Kategorie
+    local random_string=$(random_char "$lower")
+    random_string+=$(random_char "$upper")
+    random_string+=$(random_char "$digits")
+    random_string+=$(random_char "$special")
+    random_string+=$(random_char "$special")
+
+    # Fülle den Rest der Zeichenkette mit zufälligen Zeichen aus allen Kategorien
+    local all_chars="$lower$upper$digits$special"
+    for (( i=${#random_string}; i<length; i++ )); do
+        random_string+=$(random_char "$all_chars")
+    done
+
+    # Mische die Zeichenkette, um die Reihenfolge der Zeichen zufällig zu machen
+    random_string=$(echo "$random_string" | fold -w1 | shuf | tr -d '\n')
+
+    # Ausgabe des generierten Strings
+    echo "$random_string"
+}
+
+
+
+# ----------
+# - Jobhandling
+# ----------
+
+# - Run 'clean_up' for signals SIGHUP SIGINT SIGTERM
+# -
+trap clean_up SIGHUP SIGINT SIGTERM
+
+# - Create lock directory '$LOCK_DIR"
+#
+mkdir "$LOCK_DIR"
+
+
+# ----------
+# - Some checks ..
+# ----------
+
+# - Running in a terminal?
+# -
+if [[ -t 1 ]] ; then
+   terminal=true
+else
+   fatal "Script must run in a terminal."
+fi
+
+
+# ==========
+# - Begin Main Script
+# ==========
+
+# ----------
+# - Headline
+# ----------
+
+if $terminal ; then
+   echo ""
+   echo -e "\033[1m----------\033[m"
+   echo -e "\033[32m\033[1mRunning script \033[m\033[1m$script_name\033[32m .. \033[m"
+   echo -e "\033[1m----------\033[m"
+fi
+
+
+# ----------
+#  Read Configurations from $conf_file
+# ----------
+
+# - Give your default values here
+# -
+DEFAULT_FQHN_HOSTNAME="$(hostname -f)"
+
+DEFAULT_KEYCLOAK_USER="keycloak"
+
+DEFAULT_DB_NAME="keycloak"
+DEFAULT_DB_USER="keycloak"
+
+DEFAULT_KEYCLOAK_BASE_INSTALL_PATH="/opt"
+
+blank_line
+echononl "Read configuration '$(basename "${conf_file}")' .."
+if [[ -f "$conf_file" ]]; then
+   source "$conf_file" > ${log_file} 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+   warn "No configuration file '$conf_file' present.\n
+               Loading default values.."
+fi
+
+[[ -n "${FQHN_HOSTNAME}" ]] && DEFAULT_FQHN_HOSTNAME="${FQHN_HOSTNAME}"
+
+if [[ -n "$DB_TYPE" ]] ; then
+   if [[ "${DB_TYPE,,}" = "postgres" ]] || [[ "${DB_TYPE,,}" = "postgresql" ]] || [[ "${DB_TYPE,,}" = "pgsql" ]] || [[ "${DB_TYPE,,}" = "psql" ]] ; then
+
+      DEFAULT_DB_TYPE=pgsql
+
+   elif [[ "${DB_TYPE,,}" = "mysql" ]] ; then
+
+      DEFAULT_DB_TYPE=mysql
+
+   else
+      fatal "Wrong or empty Database Type (DB_TYPE) - must be 'mysql' or 'pgsql'."
+   fi
+fi
+
+[[ -n "${DB_NAME}" ]] && DEFAULT_DB_NAME="${DB_NAME}"
+[[ -n "${DB_USER}" ]] && DEFAULT_DB_NAME="${DB_USER}"
+[[ -n "${DB_PASS}" ]] &&  DEFAULT_DB_PASS="${DB_PASS}"
+
+[[ -n "${KEYCLOAK_USER}" ]] && DEFAULT_KEYCLOAK_USER="${KEYCLOAK_USER}"
+if [[ -n "${KEYCLOAK_GROUP}" ]]; then
+   DEFAULT_KEYCLOAK_GROUP="${KEYCLOAK_GROUP}"
+else
+   DEFAULT_KEYCLOAK_GROUP="$DEFAULT_KEYCLOAK_USER"
+fi
+
+[[ -n "${KEYCLOAK_BASE_INSTALL_PATH}" ]] && DEFAULT_KEYCLOAK_BASE_INSTALL_PATH="${KEYCLOAK_BASE_INSTALL_PATH}"
+
+echo -e "\033[32m--\033[m"
+echo ""
+echo "Version Number of Keycloak Server to install"
+echo ""
+echo "   see: https://keycloak.org/downloads"
+echo ""
+echo ""
+KEYCLOAK_VERSION=
+while [ "X$KEYCLOAK_VERSION" = "X" ]
+do
+   echononl "KEYCLOAK Server Version: "
+   read KEYCLOAK_VERSION
+   if [ "X$KEYCLOAK_VERSION" = "X" ]; then
+      echo -e "\n\t\033[33m\033[1mA Version number is required!\033[m\n"
+   fi
+done
+DOWNLOAD_ARCHIVE="keycloak-${KEYCLOAK_VERSION}.tar.gz"
+DOWNLOAD_URL="https://github.com/keycloak/keycloak/releases/download/${KEYCLOAK_VERSION}/${DOWNLOAD_ARCHIVE}"
+
+
+KEYCLOAK_BASE_INSTALL_PATH=
+echo ""
+echo -e "\033[32m--\033[m"
+echo ""
+echo "Specify the base directory in which keycloak is to be installed."
+echo ""
+while [[ "X${KEYCLOAK_BASE_INSTALL_PATH}" = "X" ]]; do
+   echononl "Base directory for keycloak installation [${DEFAULT_KEYCLOAK_BASE_INSTALL_PATH}]: "
+   read KEYCLOAK_BASE_INSTALL_PATH
+   if [[ "X${KEYCLOAK_BASE_INSTALL_PATH}" = "X" ]]; then
+      KEYCLOAK_BASE_INSTALL_PATH="${DEFAULT_KEYCLOAK_BASE_INSTALL_PATH}"
+   fi
+   if [[ ! -d "${KEYCLOAK_BASE_INSTALL_PATH}" ]] ; then
+      echo -e "\n\tGiven directory \033[33m\033[1m${KEYCLOAK_BASE_INSTALL_PATH}\033[m does not exist!.\n"
+      KEYCLOAK_BASE_INSTALL_PATH=""
+   fi
+done
+KEYCLOAK_INSTALL_DIR="${KEYCLOAK_BASE_INSTALL_PATH}/keycloak-${KEYCLOAK_VERSION}"
+
+if [[ -h "${KEYCLOAK_BASE_INSTALL_PATH}/keycloak" ]] ; then
+   CUR_INSTALL_DIR="$(realpath "${KEYCLOAK_BASE_INSTALL_PATH}/keycloak")"
+   CUR_VERSION="$(basename "${CUR_INSTALL_DIR}" | sed "s/^keycloak-//")"
+else
+   fatal "Cannot find a Keycloak installation in the ${KEYCLOAK_BASE_INSTALL_PATH} directory"
+fi
+
+KEYCLOAK_USER="$(stat -c '%U' "${CUR_INSTALL_DIR}")"
+if [[ -z "${KEYCLOAK_USER}" ]] ; then
+   fatal "Cannot determine the user of the Keycloak installation."
+fi
+
+KEYCLOAK_GROUP="$(stat -c '%G' "${CUR_INSTALL_DIR}")"
+if [[ -z "${KEYCLOAK_GROUP}" ]] ; then
+   fatal "Cannot determine the group of the Keycloak installation."
+fi
+
+
+FQHN_HOSTNAME=
+echo ""
+echo -e "\033[32m--\033[m"
+echo ""
+echo "Insert full qualified hostname for Keycloak Service"
+echo ""
+if [[ -n "${DEFAULT_FQHN_HOSTNAME}" ]]; then
+   while [[ "X${FQHN_HOSTNAME}" = "X" ]]; do
+      echononl "Full qualified hostname [${DEFAULT_FQHN_HOSTNAME}]: "
+      read FQHN_HOSTNAME
+      if [[ "X${FQHN_HOSTNAME}" = "X" ]]; then
+         FQHN_HOSTNAME=$DEFAULT_FQHN_HOSTNAME
+      fi
+      if [[ ! ${FQHN_HOSTNAME} =~ \. ]]; then
+         echo -e "\n\tGiven Host \033[33m\033[1m${FQHN_HOSTNAME}\033[m seems not to be a full qualified hostname.\n"
+         FQHN_HOSTNAME=""
+      fi
+   done
+else
+   while [[ "X${FQHN_HOSTNAME}" = "X" ]]; do
+      echononl "Full qualified hostname: "
+      read FQHN_HOSTNAME
+      if [[ "X${FQHN_HOSTNAME}" = "X" ]]; then
+         echo -e "\n\t\033[33m\033[1mFull qualified hostname is reqired\033[m\n"
+      fi
+      if [[ ! ${FQHN_HOSTNAME} =~ \. ]]; then
+         echo -e "\n\tGiven Host \033[33m\033[1m${FQHN_HOSTNAME}\033[m seems not to be a full qualified hostname.\n"
+         FQHN_HOSTNAME=""
+      fi
+   done
+fi
+HOSTNAME="${FQHN_HOSTNAME%%.*}"
+
+
+echo ""
+echo ""
+echo -e "\t\033[32mStart upgrade script for Keycloak Service with the following parameters\033[m"
+echo ""
+echo -e "\t(New) Keycloak Server Version...: \033[33m\033[1m${KEYCLOAK_VERSION}\033[m"
+echo ""
+if [[ -n "${CUR_VERSION}" ]] ; then
+   echo -e "\tCurrent (old) Keycloak Version..: ${CUR_VERSION}"
+else
+   echo -e "\tCurrent (old) Keycloak Version..: \033[33mkeycloak is currently NOT installed\033[m"
+fi
+echo ""
+echo -e "\tFull qualified Hostname.........: ${FQHN_HOSTNAME}"
+echo -e "\tHostname........................: ${HOSTNAME}"
+echo ""
+echo -e "\tKeycloak user...................: ${KEYCLOAK_USER}"
+echo -e "\tKeycloak group..................: ${KEYCLOAK_GROUP}"
+echo ""
+echo -e "\tKeycloak base install dir.......: ${KEYCLOAK_BASE_INSTALL_PATH}"
+echo -e "\tKeycloak install dir............: ${KEYCLOAK_INSTALL_DIR}"
+echo ""
+echo -e "\tDownload archive................: ${DOWNLOAD_ARCHIVE}"
+echo -e "\tDownload URL....................: ${DOWNLOAD_URL}"
+echo ""
+echo ""
+echononl "einverstanden (yes/no): "
+read OK
+OK=${OK,,}
+while [ "X$OK" != "Xyes" -a "X$OK" != "Xno" ]; do
+   echononl "Wrong entry! [yes/no]: "
+   read OK
+   OK=${OK,,}
+done
+[ $OK = "yes" ] || fatal Repeat with other settings..
+
+
+echo
+echo -e "\033[37m\033[1mAdjust configuration file..\033[m"
+echo
+
+_var="KEYCLOAK_USER"
+_val="${KEYCLOAK_USER}"
+echononl "Update '${_var}' configuration file .."
+if ! $(grep -q -E "^\s*${_var}=\"${_val}\"" "${conf_file}" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^\s*${_var}=.*/${_var}=\"${_val}\"/" ${conf_file} > "$log_file" 2>&1
+   if [[ "$?" = "0" ]]; then
+      echo_ok
+   else
+      echo_failed
+      error "$(cat $log_file)"
+   fi
+else
+   echo_skipped
+fi
+
+
+_var="KEYCLOAK_GROUP"
+_val="${KEYCLOAK_GROUP}"
+echononl "Update '${_var}' configuration file .."
+if ! $(grep -q -E "^\s*${_var}=\"${_val}\"" "${conf_file}" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^\s*${_var}=.*/${_var}=\"${_val}\"/" ${conf_file} > "$log_file" 2>&1
+   if [[ "$?" = "0" ]]; then
+      echo_ok
+   else
+      echo_failed
+      error "$(cat $log_file)"
+   fi
+else
+   echo_skipped
+fi
+
+_var="FQHN_HOSTNAME"
+_val="${FQHN_HOSTNAME}"
+echononl "Update '${_var}' configuration file .."
+if ! $(grep -q -E "^\s*${_var}=\"${_val}\"" "${conf_file}" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^\s*${_var}=.*/${_var}=\"${_val}\"/" ${conf_file} > "$log_file" 2>&1
+   if [[ "$?" = "0" ]]; then
+      echo_ok
+   else
+      echo_failed
+      error "$(cat $log_file)"
+   fi
+else
+   echo_skipped
+fi
+
+_var="KEYCLOAK_BASE_INSTALL_PATH"
+_val="${KEYCLOAK_BASE_INSTALL_PATH}"
+echononl "Update '${_var}' configuration file .."
+if ! $(grep -q -E "^\s*${_var}=\"${_val}\"" "${conf_file}" 2> /dev/null) ; then
+   perl -i -n -p -e "s#^s*${_var}=.*#${_var}=\"${_val}\"#" ${conf_file} > "$log_file" 2>&1
+   if [[ "$?" = "0" ]]; then
+      echo_ok
+   else
+      echo_failed
+      error "$(cat $log_file)"
+   fi
+else
+   echo_skipped
+fi
+
+blank_line
+
+#echononl "Continue upgrade (yes/no): "
+#read OK
+#OK=${OK,,}
+#while [ "X$OK" != "Xyes" -a "X$OK" != "Xno" ]; do
+#   echononl "Wrong entry! [yes/no]: "
+#   read OK
+#   OK=${OK,,}
+#done
+#[ $OK = "yes" ] || fatal Repeat with other settings..
+
+
+echo
+echo -e "\033[37m\033[1mSome pre-installation stuff..\033[m"
+echo
+
+echononl "Backup crontab"
+crontab -u root -l > ${crontab_backup_file} 2> $log_file
+if [[ "$?" = "0" ]]; then
+   echo_ok
+else
+   echo_failed
+   error "$(cat $log_file)"
+fi
+
+echononl "Disable crontab for user root"
+crontab -r -u root > ${log_file}  2>&1
+if [[ "$?" = "0" ]]; then
+   echo_ok
+else
+   echo_failed
+   error "$(cat $tmp_err_msg)"
+fi
+
+
+blank_line
+
+echononl "Stop Keycloak Service.."
+if $(systemctl is-active --quiet service keycloak.service) ; then
+   systemctl stop keycloak.service > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+blank_line
+
+
+echo
+echo -e "\033[37m\033[1mInstalling Keycloak Service..\033[m"
+echo
+
+echononl "Download the latest version (${KEYCLOAK_VERSION}) of the Keycloak Server.."
+if [[ ! -f "${working_dir}/${DOWNLOAD_ARCHIVE}" ]]; then
+   wget -O "${working_dir}/${DOWNLOAD_ARCHIVE}" "${DOWNLOAD_URL}" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+
+blank_line
+
+echononl "Backup Keycloak Installation directory.."
+if [[ -n "${CUR_INSTALL_DIR}" ]]; then
+   cp -a "${CUR_INSTALL_DIR}" "${CUR_INSTALL_DIR}.${backup_date}" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+echononl "Remove Symlink '${KEYCLOAK_BASE_INSTALL_PATH}/keycloak' .."
+rm "${KEYCLOAK_BASE_INSTALL_PATH}/keycloak"  > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+blank_line
+
+echononl "Extract the Keycloak Service files.."
+tar -C "${KEYCLOAK_BASE_INSTALL_PATH}" -xvzf "${working_dir}/${DOWNLOAD_ARCHIVE}" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+blank_line
+
+echononl "Copy 'conf/ directory from the previous installation to the new installation."
+cp -a "${CUR_INSTALL_DIR}/conf" "${KEYCLOAK_INSTALL_DIR}/" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi 
+
+echononl "Copy 'providers/ directory from the previous installation to the new installation."
+cp -a "${CUR_INSTALL_DIR}/providers" "${KEYCLOAK_INSTALL_DIR}/" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi 
+
+echononl "Copy 'themes/ directory from the previous installation to the new installation."
+cp -a "${CUR_INSTALL_DIR}/themes" "${KEYCLOAK_INSTALL_DIR}/" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi 
+
+
+echononl "Set ownbership of installation directory '${KEYCLOAK_INSTALL_DIR}'.."
+chown -R ${KEYCLOAK_USER}:${KEYCLOAK_GROUP} "${KEYCLOAK_INSTALL_DIR}" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "Give write permissions to the keycloak group.."
+chmod -R g+w "${KEYCLOAK_INSTALL_DIR}" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "Symlink keycloak -> keycloak-${KEYCLOAK_VERSION} .."
+ln -s "keycloak-${KEYCLOAK_VERSION}" "${KEYCLOAK_BASE_INSTALL_PATH}/keycloak" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi 
+
+
+_certs_installed=false
+echononl "Run script 'check_cert_for_keycloak.sh'.."
+if [[ -x "/root/bin/monitoring/check_cert_for_keycloak.sh" ]] ; then
+   /root/bin/monitoring/check_cert_for_keycloak.sh > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      cat "$log_file"
+   else
+      echo_ok
+      _certs_installed=true
+   fi
+else
+   warn "Certificate/Key for ${FQHN_HOSTNAME} cannot be provided."
+fi
+
+
+echononl "Add a cronjob for checking cert.."
+if [[ -f "$crontab_backup_file" ]]; then
+   if ! grep -iq -E "/root/bin/monitoring/check_cert_for_keycloak.sh" "$crontab_backup_file" > /dev/null 2>&1; then
+      cat <<EOF >> $crontab_backup_file
+
+# Check if cert for Keycloak service is up-to-date
+#
+51 05 * * * /root/bin/monitoring/check_cert_for_keycloak.sh
+EOF
+      if [[ "$?" -ne 0 ]] ; then
+         echo_failed
+      else
+         echo_ok
+      fi
+
+   else
+      echo_skipped
+   fi
+
+elif [[ -f "/var/spool/cron/crontabs/root" ]] ; then
+
+   if ! grep -i -E "/root/bin/monitoring/check_cert_for_keycloak.sh" /var/spool/cron/crontabs/root > /dev/null 2>&1; then
+      installation_failed=false
+      crontab -l > /tmp/tmp_crontab 2> $log_file
+      if [[ "$?" -ne 0 ]] ; then
+         installation_failed=true
+      fi
+
+      cat << EOF >> /tmp/tmp_crontab 2>> $log_file
+
+# Check if cert for Keycloak service is up-to-date
+#
+51 05 * * * /root/bin/monitoring/check_cert_for_keycloak.sh
+EOF
+      if [[ "$?" -ne 0 ]] ; then
+         installation_failed=true
+      fi
+      crontab /tmp/tmp_crontab > /dev/null 2>> $log_file
+      if [[ "$?" -ne 0 ]] ; then
+         installation_failed=true
+      fi
+      rm /tmp/tmp_crontab  > /dev/null 2>> $log_file
+      if [[ "$?" -ne 0 ]] ; then
+         installation_failed=true
+      fi
+      if ! $installation_failed ; then
+         echo_ok
+      else
+         echo_failed
+         error "Adding cronjob for checking cert failed!"
+      fi
+   else
+      echo_skipped
+   fi
+fi
+
+blank_line
+
+echononl "Creates a new and optimized server image.."
+${KEYCLOAK_BASE_INSTALL_PATH}/keycloak/bin/kc.sh build > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+
+   echononl "\033[1mcontinue anyway\033[m [yes/no]: "
+   read OK
+   while [[ "${OK,,}" != "yes" ]] && [[  "${OK,,}" != "no" ]] ; do
+      echononl "Wrong entry! - repeat [yes/nno]: "
+      read OK
+   done
+   [[ $OK = "yes" ]] || fatal "Abbruch durch User"
+
+else
+   echo_ok
+fi
+
+blank_line
+
+echononl "Start Keycloak Service"
+systemctl start keycloak.service > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "Restart NGINX Service.."
+systemctl restart nginx  > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+echo
+echo -e "\033[37m\033[1mSome post-installation stuff..\033[m"
+echo
+
+_cron_reenabled=false
+echononl "Reenable previously saved crontab from '$(basename "${crontab_backup_file}")'.."
+if [[ -f "${crontab_backup_file}" ]] ; then
+   crontab ${crontab_backup_file} > $log_file 2>&1
+   if [[ $? -eq 0 ]]; then
+      echo_ok
+      _cron_reenabled=true
+   else
+      echo_failed
+      error "$(cat $log_file)"
+   fi
+else
+   echo_skipped
+fi
+
+blank_line
+
+
+echononl "Wait until the Keycloak service has started completely."
+echo_wait
+declare -i index=0
+declare -i _max_secs_waiting=40
+keycloak_service_started=false
+while true ; do
+
+   # Try to establish a connection to localhost:8080
+   #
+   if $(curl -s -o /dev/null -I http://localhost:8080) ; then
+      echo_ok
+      keycloak_service_started=true
+      break
+   fi
+   if [[ ${index} -gt ${_max_secs_waiting} ]]; then
+      echo_failed
+      error "Could not connect to loacalhost on port 8080 after about 20 seconds!"
+      break
+   fi
+   (( index++ ))
+   sleep 1
+done
+
+blank_line
+
+echononl "Remove previously saved crontab file '$(basename "${crontab_backup_file}")'.."
+if ${_cron_reenabled} ; then
+   rm "${crontab_backup_file}" > $log_file 2>&1
+   if [[ $? -eq 0 ]]; then
+      echo_ok
+   else
+      echo_failed
+      error "$(cat $log_file)"
+   fi
+else
+   echo_skipped
+fi
+
+
+clean_up 0
+