commit 64d71f54b6ee9315f3c5c90543b6f41f8db2183a
Author: Christoph <ckubu@oopen.de>
Date:   Mon May 11 02:19:44 2020 +0200

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..9772d11
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,9 @@
+
+# - common
+*.log
+*.swp
+*.tar.gz
+log*
+
+conf/*.conf
+
diff --git a/README.install b/README.install
new file mode 100644
index 0000000..24fdbdb
--- /dev/null
+++ b/README.install
@@ -0,0 +1,110 @@
+# ===========================================================================
+# 
+# Mattermost 
+#    "is an open-source, self-hostable online chat service with file sharing, 
+#    search, and integrations). It is designed as an internal chat for 
+#    organisations and companies, and mostly markets itself as an open-source 
+#    alternative to Slac and Microsoft Teams. "
+#
+#    https://mattermost.com/
+#
+# see: 
+#    - https://docs.mattermost.com/install/install-debian.html
+#
+#    - https://docs.mattermost.com/
+#
+# Requirements:
+#
+#    - NGINX Web Service is installed
+#    - MySQL Service is installed
+#    - lets encrypt certificates available for $FQHN_HOSTNAME
+
+# =============================================================================
+
+
+
+# ---
+# 0.) Requirements
+# ---
+
+# ----------
+#
+# 0.) Create new LX Container
+#
+#    /root/bin/LXC/create-lx-container.sh
+#    ...
+#
+# 1.) Assign(Adjust user root
+#
+#    lxc-attach -n meet
+#    add_new_user.sh root
+#
+# Base Install via ansible
+#
+#    cd /home/chris/devel/git/git.oopen.de/ansible/oopen-server
+#    ansible-playbook --limit meet.oopen.de ansible-dependencies.yml
+#    ansible-playbook --limit meet.oopen.de common.yml
+#    ansible-playbook --limit meet.oopen.de scripts/install-ulogd.yml
+#    ansible-playbook --limit meet.oopen.de firewall.yml
+#
+# ----------
+
+# Adjust Firewall
+#
+cd /etc/ipt-firewall
+...
+
+# Install Postfix SMTP Service (base)
+#
+cd /usr/local/src/mailsystem
+./install_postfix_base.sh
+
+# Install Nginx Webserver
+#
+cd /usr/local/src/nginx
+./install_nginx.sh
+
+# Install update mechanism for lets encrypt certificates
+#
+cd /usr/local/src/dehydrated-cron
+./install_dehydrated.sh
+
+# Create certificate(s)
+#
+# Adjust '/var/lib/dehydrated/domains.txt'
+#
+# vim /var/lib/dehydrated/domains.txt
+#
+cat <<EOF >> /var/lib/dehydrated/domains.txt
+$FQHN_HOSTNAME
+EOF
+/var/lib/dehydrated/cron/dehydrated_cron.sh
+
+
+# ---
+# 0.1) Requirements MySQL Database Service
+# ---
+
+# Install MySQL Database Service
+#
+cd /tmp
+
+# See at 'https://dev.mysql.com/downloads/repo/apt/' which is the 
+# actual version of the apt-repository
+#
+mysql_apt_version=0.8.15-1
+wget https://dev.mysql.com/get/mysql-apt-config_${mysql_apt_version}_all.deb
+dpkg -i mysql-apt-config_${mysql_apt_version}_all.deb
+
+apt-get update
+apt-get install mysql-server
+
+
+
+# ---
+# 1.) Install Mattermost Service
+# ---
+
+# Trigger install script 'install-mattermost.sh'
+#
+./install-mattermost.sh
diff --git a/conf/mattermost.conf.sample b/conf/mattermost.conf.sample
new file mode 100644
index 0000000..2443f06
--- /dev/null
+++ b/conf/mattermost.conf.sample
@@ -0,0 +1,88 @@
+#----------------------------------------
+# Settings for Mattermost Install scripts
+#----------------------------------------
+
+# FQHN_HOSTNAME
+#
+# The full qualified histname under which bbb service
+# is available
+#
+# Defaults to full qualified hostname of the system
+#
+FQHN_HOSTNAME=""
+
+
+# MATTERMOST_USER
+#
+# The user under which Mattermost service is running.
+#
+# Defaults to: MATTERMOST_USER="mattermost"
+#
+#MATTERMOST_USER=""
+
+
+# MATTERMOST_GROUP
+#
+# The group od mattermost user.
+#
+# Defaults to: MATTERMOST_GROUP="$MATTERMOST_USER"
+#
+#MATTERMOST_GROUP=""
+
+
+# MYSQL_CREDENTIAL_ARGS
+#
+# Giving password on command line is insecure an sind mysql 5.5
+# you will get a warning doing so.
+#
+# Reading username/password fro file ist also possible, using MySQL/MariaDB
+# commandline parameter '--defaults-file'.
+#
+# Since Version 5.6, that method is considered as insecure.
+# To avoid giving the password on command line, we use an
+# encrypted option file
+#
+#    Create (encrypted) option file:
+#    $ mysql_config_editor set --login-path=local --socket=/var/run/mysqld/mysqld.sock  --user=backup --password
+#    $ Password:
+#
+#    Use of option file:
+#    $ mysql --login-path=local ...
+#
+# Example
+#    MYSQL_CREDENTIAL_ARGS="--login-path=local"
+#    MYSQL_CREDENTIAL_ARGS="--defaults-file=/etc/mysql/debian.cnf" (Debian default)
+#    MYSQL_CREDENTIAL_ARGS="--defaults-file=/usr/local/mysql/sys-maint.cnf"
+#
+#    # MariaDB 10.4.x
+#    MYSQL_CREDENTIAL_ARGS="-u root -S /tmp/mysql.sock"
+#
+# No Defaults
+#
+#MYSQL_CREDENTIAL_ARGS="--login-path=local"
+
+
+# DB_NAME
+#
+# Database Name of Mattemost's Database
+#
+# Defaults to: DB_NAME="mattermost"
+#
+#DB_NAME="mattermost"
+
+# DB_USER
+#
+# Database USER of Mattemost's Database
+#
+# Defaults to: DB_USER="mattermost"
+#
+#DB_USER="mattermost"
+
+
+# DB_PASS
+#
+# Database Password used for Mattemost's Database
+#
+# Defaults to a random created one.
+#
+#DB_PASS=""
diff --git a/install-mattermost.sh b/install-mattermost.sh
new file mode 100755
index 0000000..7efa501
--- /dev/null
+++ b/install-mattermost.sh
@@ -0,0 +1,1498 @@
+#!/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/mattermost.conf"
+
+LOCK_DIR="/tmp/$(basename $0).$$.LOCK"
+log_file="${LOCK_DIR}/${script_name%%.*}.log"
+
+backup_date="$(date +%Y-%m-%d-%H%M)"
+
+
+# ----------
+# Base Function(s)
+# ----------
+
+clean_up() {
+
+   # Perform program exit housekeeping
+   rm -rf "$LOCK_DIR"
+   blank_line
+   exit $1
+}
+
+echononl(){
+   if $terminal ; then
+      echo X\\c > /tmp/shprompt$$
+      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(){
+   echo ""
+   if $terminal ; then
+      echo -e "   [ \033[31m\033[1mFatal\033[m ] $*"
+   else
+      echo -e "   [ Fatal ] $*"
+   fi
+   echo ""
+   if $terminal ; then
+      echo -e "             \033[1mScript terminated\033[m.."
+   else
+      echo -e "             Script terminated.."
+   fi
+   echo ""
+   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// /}"
+
+}
+
+
+
+# ----------
+# - 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_MATTERMOST_USER="mattermost"
+
+DEFAULT_DB_NAME="mattermost"
+DEFAULT_DB_USER="mattermost"
+
+# generate random password
+regexp_digit="([23456789].*){2}"
+regexp_special_char="([-_%+].*){2}"
+regexp_not_alowed="([0ODl18B])"
+LENGTH=16
+
+while [ 1 ] ; do
+
+   DEFAULT_DB_PASS="$(head -c 300 /dev/urandom | tr -cd 'a-zA-Z1-9\-_%' | head -c ${LENGTH})"
+
+   # - Check Password
+   # -
+   if [[ "$DEFAULT_DB_PASS" =~ $regexp_not_alowed ]] ; then
+      continue
+   fi
+   if [[ ! "$DEFAULT_DB_PASS" =~ $regexp_special_char ]] ; then
+      continue
+   fi
+   if [[ ! "$DEFAULT_DB_PASS" =~ $regexp_digit ]] ; then
+      continue
+   fi
+
+   break
+
+done
+
+echo "$conf_file"
+
+if [[ -f "$conf_file" ]]; then
+   source "$conf_file"
+else
+   warn "No configuration file '$conf_file' present.\n
+             Loading default values.."
+fi
+
+[[ -n "$FQHN_HOSTNAME" ]] && DEFAULT_FQHN_HOSTNAME="$FQHN_HOSTNAME"
+
+[[ -n "$DB_NAME" ]] && DEFAULT_DB_NAME="$DB_NAME"
+[[ -n "$DB_USER" ]] && DEFAULT_DB_NAME="$DB_USER"
+[[ -n "$DB_PASS" ]] &&  DEFAULT_DB_PASS="$DB_PASS"
+
+[[ -n "$MATTERMOST_USER" ]] && DEFAULT_MATTERMOST_USER="$MATTERMOST_USER"
+if [[ -n "$MATTERMOST_GROUP" ]]; then
+   DEFAULT_MATTERMOST_GROUP="$MATTERMOST_GROUP"
+else
+   DEFAULT_MATTERMOST_GROUP="$DEFAULT_MATTERMOST_USER"
+fi
+
+
+blank_line
+echononl "Detect distribution/release of running OS.."
+detect_os > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+	echo_failed
+	error "$(cat "$log_file")"
+else
+	echo_ok
+fi
+
+
+echo -e "\033[32m--\033[m"
+echo ""
+echo "Version Number of Mattermost Server to install"
+echo ""
+echo ""
+MATTERMOST_VERSION=
+while [ "X$MATTERMOST_VERSION" = "X" ]
+do
+   echononl "Mattermost Server Version: "
+   read MATTERMOST_VERSION
+   if [ "X$MATTERMOST_VERSION" = "X" ]; then
+      echo -e "\n\t\033[33m\033[1mA Version number is required!\033[m\n"
+   fi
+done
+DOWNLOAD_ARCHIVE="mattermost-${MATTERMOST_VERSION}-linux-amd64.tar.gz"
+DOWNLOAD_URL="https://releases.mattermost.com/${MATTERMOST_VERSION}/${DOWNLOAD_ARCHIVE}"
+
+
+
+FQHN_HOSTNAME=
+echo ""
+echo -e "\033[32m--\033[m"
+echo ""
+echo "Insert full qualified hostname for Mattermost 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="${FQHN_HOSTNAME%%.*}"
+
+echo ""
+echo "--"
+echo ""
+echo "Enter user and group for Mattermost Service."
+echo ""
+MATTERMOST_USER=
+while [ "X$MATTERMOST_USER" = "X" ]
+do
+   echononl "Mattermost user [${DEFAULT_MATTERMOST_USER}]: "
+   read MATTERMOST_USER
+   if [ "X$MATTERMOST_USER" = "X" ]; then
+      MATTERMOST_USER=$DEFAULT_MATTERMOST_USER
+   fi
+done
+MATTERMOST_GROUP=
+while [ "X$MATTERMOST_GROUP" = "X" ]
+do
+   echononl "Mattermost group [$DEFAULT_MATTERMOST_GROUP]: "
+   read MATTERMOST_GROUP
+   if [ "X$MATTERMOST_GROUP" = "X" ]; then
+      MATTERMOST_GROUP=$DEFAULT_MATTERMOST_GROUP
+   fi
+done
+
+
+
+
+DB_NAME=
+echo ""
+echo -e "\033[32m--\033[m"
+echo ""
+echo "Enter Database Name used by Mattermost Service"
+echo ""
+if [[ -n "$DEFAULT_DB_NAME" ]]; then
+   while [[ "X${DB_NAME}" = "X" ]]; do
+      echononl "Database Name [${DEFAULT_DB_NAME}]: "
+      read DB_NAME
+      if [[ "X${DB_NAME}" = "X" ]]; then
+         DB_NAME=$DEFAULT_DB_NAME
+      fi
+   done
+else
+   while [[ "X${DB_NAME}" = "X" ]]; do
+      echononl "Database Name: "
+      read DB_NAME
+      if [[ "X${DB_NAME}" = "X" ]]; then
+         echo -e "\n\t\033[33m\033[1m Database Name is reqired\033[m\n"
+      fi
+   done
+fi
+
+DB_USER=
+echo ""
+echo -e "\033[32m--\033[m"
+echo ""
+echo "Enter Database User used by Mattermost Service"
+echo ""
+if [[ -n "$DEFAULT_DB_USER" ]]; then
+   while [[ "X${DB_USER}" = "X" ]]; do
+      echononl "Database User [${DEFAULT_DB_USER}]: "
+      read DB_USER
+      if [[ "X${DB_USER}" = "X" ]]; then
+         DB_USER=$DEFAULT_DB_USER
+      fi
+   done
+else
+   while [[ "X${DB_USER}" = "X" ]]; do
+      echononl "Database User: "
+      read DB_USER
+      if [[ "X${DB_USER}" = "X" ]]; then
+         echo -e "\n\t\033[33m\033[1m Database User is reqired\033[m\n"
+      fi
+   done
+fi
+
+DB_PASS=
+echo ""
+echo -e "\033[32m--\033[m"
+echo ""
+echo "Enter Database Password used by Mattermost Service"
+echo ""
+if [[ -n "$DEFAULT_DB_PASS" ]]; then
+   while [[ "X${DB_PASS}" = "X" ]]; do
+      echononl "Database Password [${DEFAULT_DB_PASS}]: "
+      read DB_PASS
+      if [[ "X${DB_PASS}" = "X" ]]; then
+         DB_PASS=$DEFAULT_DB_PASS
+      fi
+   done
+else
+   while [[ "X${DB_PASS}" = "X" ]]; do
+      echononl "Database Password: "
+      read DB_PASS
+      if [[ "X${DB_PASS}" = "X" ]]; then
+         echo -e "\n\t\033[33m\033[1m Database Password is reqired\033[m\n"
+      fi
+   done
+fi
+
+
+if [[ -n "$MYSQL_CREDENTIAL_ARGS" ]] ; then
+   if ! $(mysql $MYSQL_CREDENTIAL_ARGS -N -s -e 'quit' > /dev/null 2>&1) ; then
+      fatal "Parameter MYSQL_CREDENTIAL_ARGS is given, but a connection to MySQL Service failed.!"
+   fi
+   USE_MYSQL_CREDENTIAL_ARGS=true
+else
+   USE_MYSQL_CREDENTIAL_ARGS=false
+
+   _MYSQL_ROOT_PW=""
+   echo ""
+   echo -e "\033[32m--\033[m"
+   echo ""
+   echo "Insert root password of MySQL Database Service"
+   echo ""
+   while [ "X${_MYSQL_ROOT_PW}" = "X" ]; do
+
+      echononl "Passworteingabe: "
+      read -s _MYSQL_ROOT_PW
+      if [ "X${_MYSQL_ROOT_PW}" = "X" ]; then
+         echo -e "\n\t\033[33m\033[1mPassworteingabe erforderlich!\033[m\n"
+         continue
+      fi
+      if $(pgrep mysqld_safe > /dev/null 2>&1) || $(pgrep mysqld > /dev/null 2>&1); then
+         if $(mysql --user="root" --password="$_MYSQL_ROOT_PW"  -N -s -e 'quit' > /dev/null 2>&1) ; then
+            MYSQL_ROOT_PW=$_MYSQL_ROOT_PW
+         else
+            echo -e "\n\t\033[33m\033[1mFalsches Passwort\033[m\n"
+            _MYSQL_ROOT_PW=""
+         fi
+      else
+         fatal "MySQL seems not be running. Start MySQL Service and try installing mattermost again."
+      fi
+   done
+fi
+
+
+
+echo ""
+echo ""
+echo -e "\t\033[32mStart install script for Mattermost Server with the following parameters\033[m"
+echo ""
+echo -e "\tMattermost Server Version: \033[33m\033[1m$MATTERMOST_VERSION\033[m"
+echo ""
+echo -e "\tFull qualified Hostname..: $FQHN_HOSTNAME"
+echo -e "\tHostname.................: $HOSTNAME"
+echo ""
+echo -e "\tMattermost user..........: $MATTERMOST_USER"
+echo -e "\tMattermost group.........: $MATTERMOST_GROUP"
+echo ""
+echo ""
+if $USE_MYSQL_CREDENTIAL_ARGS ; then
+   echo -e "\tMYSQL_CREDENTIAL_ARGS....: $MYSQL_CREDENTIAL_ARGS"
+else
+   echo -e "\tRoot password MySQL......: **"
+fi
+echo ""
+echo -e "\tDatabase Name............: $DB_NAME"
+echo -e "\tDatabase User............: $DB_USER"
+echo -e "\tDatabase Password........: $DB_PASS"
+echo ""
+echononl "einverstanden (yes/no): "
+read OK
+OK=${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 ""
+
+
+if ! $USE_MYSQL_CREDENTIAL_ARGS ; then
+   MYSQL_CREDENTIAL_ARGS="--user='root' --password=$_MYSQL_ROOT_PW"
+   if ! $(mysql $MYSQL_CREDENTIAL_ARGS -N -s -e 'quit' > /dev/null 2>&1) ; then
+      fatal "Parameter MYSQL_CREDENTIAL_ARGS is given, but a connection to MySQL Service failed.!"
+   fi
+fi
+
+
+
+echo
+echo -e "\033[37m\033[1mSome checks....\033[m"
+echo
+
+_failed=false
+echononl "Check if Nginx Webservice is installed.."
+if $(dpkg -s nginx-extras > "$log_file" 2>&1) ; then
+   nginx_installed=true
+elif $(dpkg -s nginx-full > "$log_file" 2>&1) ; then
+   nginx_installed=true
+else
+   nginx_installed=false
+fi
+if $nginx_installed ; then
+   echo -e "\033[85G[ \033[32mYES\033[m ]"
+else
+   echo -e "\033[85G[ \033[1;31mNOT installed\033[m ]"
+fi
+
+_failed=false
+echononl "Check if MySQL Database Service is installed.."
+if $(dpkg -s mysql-server > "$log_file" 2>&1) ; then
+   mysql_server_installed=true
+else
+   mysql_server_installed=false
+fi
+if $mysql_server_installed ; then
+   echo -e "\033[85G[ \033[32mYES\033[m ]"
+else
+   echo -e "\033[85G[ \033[1;31mNOT installed\033[m ]"
+fi
+
+
+_failed=false
+echononl "Check if certificate for '$FQHN_HOSTNAME' is present.."
+if [[ -d "/var/lib/dehydrated/certs/${FQHN_HOSTNAME}" ]] ; then
+   if [[ -h "/var/lib/dehydrated/certs/${FQHN_HOSTNAME}/fullchain.pem" ]]; then
+      cert_present=true
+   else
+      cert_present=false
+   fi
+else
+   cert_present=false
+fi
+if $cert_present ; then
+   echo -e "\033[85G[ \033[32mYES\033[m ]"
+else
+   echo -e "\033[85G[ \033[1;31mNOT present\033[m ]"
+fi
+
+if ! $nginx_installed || ! $mysql_server_installed ; then
+
+   if ! $cert_present ; then
+
+      fatal "Prerequisites are a correct installation of the NGINX Web Service as well 
+             as a correct installation of the MySQL database service. 
+      
+             It's also highly recommended to have a valid certificate for your 
+             FQHN Hostname '${FQHN_HOSTNAME}'."
+
+   else
+
+      fatal "Prerequisites are a correct installation of the NGINX Web Service as well 
+             as a correct installation of the MySQL database service."
+   fi
+
+elif ! $cert_present ; then
+
+   warn "It is highly recommended to have a valid certificate for your FQHN Hostname '${FQHN_HOSTNAME}'."
+
+   echononl "\033[1mcontinue anyway\033[m [yes/no]: "
+   read OK
+   OK="$(echo "$OK" | tr '[:upper:]' '[:lower:]')"
+   while [[ "$OK" != "yes" ]] && [[  "$OK" != "no" ]] ; do
+      echononl "Wrong entry! - repeat [yes/nno]: "
+      read OK
+   done
+   [[ $OK = "yes" ]] || fatal "Abbruch durch User"
+
+fi
+
+
+echo
+echo -e "\033[37m\033[1mSome pre-installation stuff..\033[m"
+echo
+
+echononl "Create Database User '${DB_USER}' with Password '${DB_PASS}'.."
+if [[ "$(mysql $MYSQL_CREDENTIAL_ARGS  -N -s -e \
+         "SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '$DB_USER')" 2>/dev/null)" = 1 ]]; then
+   echo_skipped
+else
+   mysql $MYSQL_CREDENTIAL_ARGS  -N -s -e \
+      "CREATE USER '$DB_USER'@'localhost' IDENTIFIED BY '${DB_PASS}'" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+echononl "Create Database '${DB_NAME}'.."
+if [[ "$(mysql $MYSQL_CREDENTIAL_ARGS  -N -s -e \
+         "SHOW DATABASES LIKE '${DB_NAME}'" 2>/dev/null)" = "${DB_NAME}" ]]; then
+
+   echo_skipped
+else
+   mysql $MYSQL_CREDENTIAL_ARGS  -N -s -e "CREATE DATABASE ${DB_NAME}" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+echononl "Grant access privileges to the user '${DB_USER}'’."
+mysql $MYSQL_CREDENTIAL_ARGS  -N -s -e \
+   "GRANT ALL PRIVILEGES ON ${DB_NAME}.* to '${DB_USER}'@'localhost';" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "FLUSH PRIVILEGES to dadabase engine .."
+mysql $MYSQL_CREDENTIAL_ARGS  -N -s -e \
+   "FLUSH PRIVILEGES" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+echo
+echo -e "\033[37m\033[1mInstalling Mattermost Server..\033[m"
+echo
+
+echononl "Create the Mattermost (system) group.."
+if cat /etc/group | grep -e "^${MATTERMOST_GROUP}:" > /dev/null  2>&1  ; then
+   echo_skipped
+else
+   groupadd -r $MATTERMOST_GROUP > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+echononl "Create the Mattermost (system) user.."
+if id -u $MATTERMOST_USER > /dev/null 2>&1; then
+   echo_skipped
+else
+   useradd -r -M -d /opt/mattermost -s /bin/false -g $MATTERMOST_GROUP $MATTERMOST_USER > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+echononl "Download the latest version (${MATTERMOST_VERSION}) of the Mattermost Server.."
+if [[ ! -f "${working_dir}/mattermost-${MATTERMOST_VERSION}-linux-amd64.tar.gz" ]]; then
+   wget -O "${working_dir}/${DOWNLOAD_ARCHIVE}" "${DOWNLOAD_URL}" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+echononl "Backup Mattermost Installation directory.."
+if [[ -d "/opt/mattermost" ]]; then
+   cp -a "/opt/mattermost" "/opt/mattermost.${backup_date}" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+echononl "Extract the Mattermost Server files.."
+tar -C /opt -xvzf "${working_dir}/${DOWNLOAD_ARCHIVE}" > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "Set ownbership of installation directors '/opt/mattermost'.."
+chown -R ${MATTERMOST_USER}:${MATTERMOST_GROUP} /opt/mattermost > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "Give write permissions to the mattermost group.."
+chmod -R g+w /opt/mattermost> "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "Backup file '/opt/mattermost/config/config.json'.."
+if [[ ! -f "/opt/mattermost/config/config.json.ORIG" ]]; then
+   cp -a /opt/mattermost/config/config.json /opt/mattermost/config/config.json.ORIG > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+
+echo
+echo -e "\033[37m\033[1mConfigure Mattermost - file '/opt/mattermost/config/config.json'..\033[m"
+echo
+
+echononl "Set up 'DriverName'.."
+if ! $(grep -q -E "^\s*\"DriverName\":\s+mysql" /opt/mattermost/config/config.json 2> "$log_file") ; then 
+
+   _found=false
+   :> ${LOCK_DIR}/config.json
+   :> $log_file
+
+   while IFS='' read -r _line || [[ -n $_line ]] ; do
+
+
+      if $_found && echo "$_line" | grep -iq -E "^\s*\"DriverName\":" 2> /dev/null ; then
+         cat <<EOF >> ${LOCK_DIR}/config.json 2> "$log_file"
+   "DriverName": "mysql",
+EOF
+      elif $_found && echo "$_line" | grep -iq -E "^\s*\"DataSource\":" 2> /dev/null ; then
+         cat <<EOF >> ${LOCK_DIR}/config.json 2> "$log_file"
+   "DataSource": "${DB_USER}:${DB_PASS}@tcp(localhost:3306)/${DB_NAME}?charset=utf8mb4,utf8\\u0026readTimeout=30s\\u0026writeTimeout=30s",
+EOF
+      else
+         echo "$_line" >> ${LOCK_DIR}/config.json 2> "$log_file"
+      fi
+
+      if ! $_found && echo "$_line" | grep -iq -E "^\s*\"SqlSettings\"" 2> /dev/null ; then
+         _found=true
+      fi
+
+      if $_found && echo "$_line" | grep -iq -E "^\s*\}," 2> /dev/null ; then
+         _found=false
+      fi
+
+   done < "/opt/mattermost/config/config.json"
+
+   cp -a "${LOCK_DIR}/config.json" /opt/mattermost/config/config.json >> "$log_file" 2>&1
+   
+   if [[ -s "$log_file" ]] ; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+
+else
+   echo_skipped
+fi
+
+echononl "Reset ownbership of '/opt/mattermost/config/config.json'.."
+chown ${MATTERMOST_USER}:${MATTERMOST_GROUP} /opt/mattermost/config/config.json > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+
+echo
+echo -e "\033[37m\033[1mSetup Mattermost to use systemd for starting and stopping..\033[m"
+echo
+
+echononl "Create a systemd unit file.."
+cat <<EOF > /etc/systemd/system//mattermost.service 2>"$log_file"
+[Unit]
+Description=Mattermost
+After=network.target
+After=mysql.service
+Requires=mysql.service
+
+[Service]
+Type=notify
+ExecStart=/opt/mattermost/bin/mattermost
+TimeoutStartSec=3600
+Restart=always
+RestartSec=10
+WorkingDirectory=/opt/mattermost
+User=$MATTERMOST_USER
+Group=$MATTERMOST_GROUP
+LimitNOFILE=524288
+
+[Install]
+WantedBy=multi-user.target
+EOF
+if [[ -s "$log_file" ]] ; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+echononl "Make systemd load the new unit.."
+systemctl daemon-reload > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "Set Mattermost Service to start on machine start up.."
+systemctl enable mattermost.service > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+blank_line
+echononl "Start Mattermost Service"
+systemctl start mattermost.service > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+
+
+echo
+echo -e "\033[37m\033[1mSome post-installation stuff..\033[m"
+echo
+
+echononl "Create/Update configuration file '$(basename "$conf_file")'"
+if [[ -f "$conf_file" ]] ; then
+   echo_skipped
+else
+   cp -a "${conf_file}.sample" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+
+_key="FQHN_HOSTNAME"
+_val="$FQHN_HOSTNAME"
+echononl "Update Parameter '$_key'.."
+if $(grep -q -E "^\s*$_key=\"?$_val\"?\s*$" "$conf_file" 2> /dev/null) ; then
+   echo_skipped
+elif $(grep -q -E "^\s*$_key=" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^\s*$_key=.*/${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif $(grep -q -E "^\s*#\s*${_key}" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^(\s*\#\s*$_key=.*)/\1\n${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   cat <<EOF >> "$conf_file" 2> "$log_file"
+
+${_key}=${_val}
+EOF
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+
+_key="MATTERMOST_USER"
+_val="$MATTERMOST_USER"
+echononl "Update Parameter '$_key'.."
+if $(grep -q -E "^\s*$_key=\"?$_val\"?\s*$" "$conf_file" 2> /dev/null) ; then
+   echo_skipped
+elif $(grep -q -E "^\s*$_key=" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^\s*$_key=.*/${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif $(grep -q -E "^\s*#\s*${_key}" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^(\s*\#\s*$_key=.*)/\1\n${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   cat <<EOF >> "$conf_file" 2> "$log_file"
+
+${_key}=${_val}
+EOF
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+
+_key="MATTERMOST_GROUP"
+_val="$MATTERMOST_GROUP"
+echononl "Update Parameter '$_key'.."
+if $(grep -q -E "^\s*$_key=\"?$_val\"?\s*$" "$conf_file" 2> /dev/null) ; then
+   echo_skipped
+elif $(grep -q -E "^\s*$_key=" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^\s*$_key=.*/${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif $(grep -q -E "^\s*#\s*${_key}" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^(\s*\#\s*$_key=.*)/\1\n${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   cat <<EOF >> "$conf_file" 2> "$log_file"
+
+${_key}=${_val}
+EOF
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+
+_key="DB_NAME"
+_val="$DB_NAME"
+echononl "Update Parameter '$_key'.."
+if $(grep -q -E "^\s*$_key=\"?$_val\"?\s*$" "$conf_file" 2> /dev/null) ; then
+   echo_skipped
+elif $(grep -q -E "^\s*$_key=" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^\s*$_key=.*/${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif $(grep -q -E "^\s*#\s*${_key}" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^(\s*\#\s*$_key=.*)/\1\n${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   cat <<EOF >> "$conf_file" 2> "$log_file"
+
+${_key}=${_val}
+EOF
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+
+_key="DB_USER"
+_val="$DB_USER"
+echononl "Update Parameter '$_key'.."
+if $(grep -q -E "^\s*$_key=\"?$_val\"?\s*$" "$conf_file" 2> /dev/null) ; then
+   echo_skipped
+elif $(grep -q -E "^\s*$_key=" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^\s*$_key=.*/${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif $(grep -q -E "^\s*#\s*${_key}" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s/^(\s*\#\s*$_key=.*)/\1\n${_key}=\"${_val}\"/" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   cat <<EOF >> "$conf_file" 2> "$log_file"
+
+${_key}=${_val}
+EOF
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+
+_key="DB_PASS"
+_val="$DB_PASS"
+echononl "Update Parameter '$_key'.."
+if $(grep -q -E "^\s*$_key=\"?$_val\"?\s*$" "$conf_file" 2> /dev/null) ; then
+   echo_skipped
+elif $(grep -q -E "^\s*$_key=" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s§^\s*$_key=.*§${_key}=\"${_val}\"§" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif $(grep -q -E "^\s*#\s*${_key}" "$conf_file" 2> /dev/null) ; then
+   perl -i -n -p -e "s&^(\s*\#\s*$_key=.*)&\1\n${_key}=\"${_val}\"&" "$conf_file" > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   cat <<EOF >> "$conf_file" 2> "$log_file"
+
+${_key}="${_val}"
+EOF
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+
+
+
+
+clean_up 0
+
+
+echo
+echo -e "\033[37m\033[1mUpdate file '/etc/systemd/system.conf'....\033[m"
+echo
+
+echononl "Set Parameter 'DefaultLimitNOFILE'.."
+if ! $(grep -q -E "^\s*DefaultLimitNOFILE=" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^(\s*#DefaultLimitNOFILE=.*)/\1\nDefaultLimitNOFILE=1048576/" \
+      /etc/systemd/system.conf  > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif ! $(grep -q -E "^\s*DefaultLimitNOFILE=1048576" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^\s*DefaultLimitNOFILE=.*/DefaultLimitNOFILE=1048576/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+echononl "Set Parameter 'DefaultLimitNPROC'.."
+if ! $(grep -q -E "^\s*DefaultLimitNPROC=" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^(\s*#DefaultLimitNPROC=.*)/\1\nDefaultLimitNPROC=1048576/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif ! $(grep -q -E "^\s*DefaultLimitNPROC=1048576" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^\s*DefaultLimitNPROC=.*/DefaultLimitNPROC=1048576/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+echononl "Set Parameter 'DefaultTasksMax'.."
+if ! $(grep -q -E "^\s*DefaultTasksMax=" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^(\s*#DefaultTasksMax=.*)/\1\nDefaultTasksMax=1048576/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif ! $(grep -q -E "^\s*DefaultTasksMax=1048576" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^\s*DefaultTasksMax=.*/DefaultTasksMax=1048576/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+echononl "Set Parameter 'DefaultLimitRTPRIO'.."
+if ! $(grep -q -E "^\s*DefaultLimitRTPRIO=" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^(\s*#DefaultLimitRTPRIO=.*)/\1\nDefaultLimitRTPRIO=infinity/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif ! $(grep -q -E "^\s*DefaultLimitRTPRIO=infinity" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^\s*DefaultLimitRTPRIO=.*/DefaultLimitRTPRIO=infinity/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+echononl "Set Parameter 'DefaultLimitRTTIME'.."
+if ! $(grep -q -E "^\s*DefaultLimitRTTIME=" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^(\s*#DefaultLimitRTTIME=.*)/\1\nDefaultLimitRTTIME=infinity/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif ! $(grep -q -E "^\s*DefaultLimitRTTIME=infinity" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^\s*DefaultLimitRTTIME=.*/DefaultLimitRTTIME=infinity/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+_failed=false
+echononl "Set Parameter 'DefaultLimitCORE'.."
+if ! $(grep -q -E "^\s*DefaultLimitCORE=" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^(\s*#DefaultLimitCORE=.*)/\1\nDefaultLimitCORE=infinity/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+elif ! $(grep -q -E "^\s*DefaultLimitCORE=infinity" /etc/systemd/system.conf 2> /dev/null); then
+   perl -i -n -p -e "s/^\s*DefaultLimitCORE=.*/DefaultLimitCORE=infinity/" \
+      /etc/systemd/system.conf > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+
+echononl "Reload Systemd .."
+systemctl daemon-reload > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+
+echo
+echo -e "\033[37m\033[1mSome Certifikation/Key stuff..\033[m"
+echo
+
+cert_copied=false
+echononl "Copy Snakeoil Cert to file '/etc/ssl/fullchain.pem'.."
+if [[ ! -f "/etc/ssl/fullchain.pem" ]] && [[ ! -h "/etc/ssl/fullchain.pem" ]]; then
+   cp /etc/ssl/certs/ssl-cert-snakeoil.pem /etc/ssl/fullchain.pem > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+      cert_copied=true
+   fi
+else
+   echo_skipped
+fi
+
+perm_cert="644"
+echononl "Set Permission $perm_cert on file '/etc/ssl/fullchain.pem'.."
+if $cert_copied ; then
+   chmod 644 /etc/ssl/fullchain.pem > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+if [[ ! -h "/etc/ssl/${FQHN_HOSTNAME}.crt" ]]; then
+   if [[ -f "/etc/ssl/${FQHN_HOSTNAME}.crt" ]] ; then
+      echononl "Remove file '/etc/ssl/${FQHN_HOSTNAME}.crt'.."
+      rm "/etc/ssl/${FQHN_HOSTNAME}.crt" > "$log_file" 2>&1
+      if [[ $? -ne 0 ]]; then
+         echo_failed
+         error "$(cat "$log_file")"
+      else
+         echo_ok
+      fi
+   fi
+   echononl "Set Symlink '/etc/ssl/${FQHN_HOSTNAME}.crt --> fullchain.pem'.."
+   ln -s fullchain.pem /etc/ssl/${FQHN_HOSTNAME}.crt > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echononl "Set Symlink '/etc/ssl/${FQHN_HOSTNAME}.crt --> fullchain.pem'.."
+   echo_skipped
+fi
+
+blank_line
+
+key_copied=false
+echononl "Copy Snakeoil Key to file '/etc/ssl/privkey.pem'.."
+if [[ ! -f "/etc/ssl/privkey.pem" ]] && [[ ! -h "/etc/ssl/privkey.pem" ]]; then
+   cp  /etc/ssl/private/ssl-cert-snakeoil.key /etc/ssl/privkey.pem > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+      key_copied=true
+   fi
+else
+   echo_skipped
+fi
+
+perm_key="644"
+echononl "Set Permission $perm_key on file '/etc/ssl/privkey.pem'.."
+if $key_copied ; then
+   chmod 644 /etc/ssl/privkey.pem > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+if [[ ! -h "/etc/ssl/${FQHN_HOSTNAME}.key" ]]; then
+   if [[ -f "/etc/ssl/${FQHN_HOSTNAME}.key" ]] ; then
+      echononl "Remove file '/etc/ssl/${FQHN_HOSTNAME}.key'.."
+      rm "/etc/ssl/${FQHN_HOSTNAME}.key" > "$log_file" 2>&1
+      if [[ $? -ne 0 ]]; then
+         echo_failed
+         error "$(cat "$log_file")"
+      else
+         echo_ok
+      fi
+   fi
+   echononl "Set Symlink '/etc/ssl/${FQHN_HOSTNAME}.key --> privkey.pem'.."
+   ln -s fullchain.pem /etc/ssl/${FQHN_HOSTNAME}.key > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echononl "Set Symlink '/etc/ssl/${FQHN_HOSTNAME}.key --> privkey.pem'.."
+   echo_skipped
+fi
+
+
+
+echo
+echo -e "\033[37m\033[1mSome naming stuff..\033[m"
+echo
+
+echononl "Change /etc/hostname - set entry to '$FQHN_HOSTNAME'.."
+if [[ "$(head -1 /etc/hostname)" != "$FQHN_HOSTNAME" ]]; then
+   cat <<EOF > /etc/hostname
+$FQHN_HOSTNAME
+EOF
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+else
+   echo_skipped
+fi
+
+blank_line
+
+echo -e "   Take care '/etc/hosts' contains line '127.0.1.1 ${FQHN_HOSTNAME} $HOSTNAME'.."
+echononl "  \033[1m127.0.1.1 ${FQHN_HOSTNAME} $HOSTNAME\033[m .."
+if ! $(grep -q -E "^\s*127.0.1.1 ${FQHN_HOSTNAME} $HOSTNAME" /etc/hosts 2> "$log_file") ; then
+   if $(grep -q -E "^\s*127.0.1.1" /etc/hosts 2> "$log_file") ; then
+      perl -i -n -p -e "s/(^\s*127.0.1.1.*)/#\1\n127.0.1.1 ${FQHN_HOSTNAME} $HOSTNAME/" \
+         /etc/hosts > "$log_file" 2>&1
+      if [[ $? -ne 0 ]]; then
+         echo_failed
+         error "$(cat "$log_file")"
+      else
+         echo_ok
+      fi
+   elif $(grep -q -E "^\s*127.0.0.1" /etc/hosts 2> "$log_file") ; then
+      perl -i -n -p -e "s/(^\s*127.0.0.1.*)/\1\n127.0.1.1 ${FQHN_HOSTNAME} $HOSTNAME/" \
+         /etc/hosts > "$log_file" 2>&1
+      if [[ $? -ne 0 ]]; then
+         echo_failed
+         error "$(cat "$log_file")"
+      else
+         echo_ok
+      fi
+   else
+      cat <<EOF >> /etc/hosts 2> "$log_file"
+127.0.1.1 ${FQHN_HOSTNAME} $HOSTNAME
+EOF
+      if [[ $? -ne 0 ]]; then
+         echo_failed
+         error "$(cat "$log_file")"
+      else
+         echo_ok
+      fi
+   fi
+else
+   echo_skipped
+fi
+
+
+
+echo
+echo -e "\033[37m\033[1mRepository stuff..\033[m"
+echo
+
+
+echononl "Add the '$JITSI_REPOSITORY_VERSION' Jitsi package repository.."
+echo "deb https://download.jitsi.org ${JITSI_REPOSITORY_VERSION}/" > /etc/apt/sources.list.d/jitsi-${JITSI_REPOSITORY_VERSION}.list
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+if [[ "$JITSI_REPOSITORY_VERSION" = "stable" ]]; then
+   if [[ -f "/etc/apt/sources.list.d/jitsi-unstable.list" ]]; then
+      echononl "Remove Repository List for 'unstable' jitsi packages.."
+      rm "/etc/apt/sources.list.d/jitsi-unstable.list" > "$log_file" 2>&1
+      if [[ $? -ne 0 ]]; then
+         echo_failed
+         error "$(cat "$log_file")"
+      else
+         echo_ok
+      fi
+   fi
+else
+   if [[ -f "/etc/apt/sources.list.d/jitsi-stable.list" ]]; then
+      echononl "Remove Repository List for 'stable' jitsi packages.."
+      rm "/etc/apt/sources.list.d/jitsi-stable.list" > "$log_file" 2>&1
+      if [[ $? -ne 0 ]]; then
+         echo_failed
+         error "$(cat "$log_file")"
+      else
+         echo_ok
+      fi
+   fi
+fi
+
+echononl "Add the Jitsi Maintainer gpg key.."
+wget -qO -  https://download.jitsi.org/jitsi-key.gpg.key 2> "$log_file" | sudo apt-key add - > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+echononl "Update Repository.."
+apt-get update > "$log_file" 2>&1
+if [[ $? -ne 0 ]]; then
+   echo_failed
+   error "$(cat "$log_file")"
+else
+   echo_ok
+fi
+
+# Ensure support is available for apt repositories served via HTTPS
+#
+echononl "Install 'apt-transport-https'.."
+if $(dpkg -s apt-transport-https > "$log_file" 2>&1) ; then
+   echo_skipped
+else
+   apt-get install -y apt-transport-https > "$log_file" 2>&1
+   if [[ $? -ne 0 ]]; then
+      echo_failed
+      error "$(cat "$log_file")"
+   else
+      echo_ok
+   fi
+fi
+
+info "To ensure, your system is fully prepared for installing Jitsi Meet, it is 
+             recommend to \033[1mreboot the system before installing Jitsi Meet\033[m."
+
+clean_up 0