diff --git a/app/scripts/install_haproxy_exporter.sh b/app/scripts/install_haproxy_exporter.sh
index 9d260d9..66a1e0f 100644
--- a/app/scripts/install_haproxy_exporter.sh
+++ b/app/scripts/install_haproxy_exporter.sh
@@ -1,44 +1,49 @@
 #!/bin/bash
 for ARGUMENT in "$@"
 do
-    KEY=$(echo $ARGUMENT | cut -f1 -d=)
-    VALUE=$(echo $ARGUMENT | cut -f2 -d=)
+    KEY=$(echo "$ARGUMENT" | cut -f1 -d=)
+    VALUE=$(echo "$ARGUMENT" | cut -f2 -d=)
 
     case "$KEY" in
-            PROXY)              PROXY=${VALUE} ;;
-            HOST)    HOST=${VALUE} ;;
-            USER)    USER=${VALUE} ;;
-            PASS)    PASS=${VALUE} ;;
-            KEY)    KEY=${VALUE} ;;
+      PROXY)    PROXY=${VALUE} ;;
+      HOST)     HOST=${VALUE} ;;
+      USER)     USER=${VALUE} ;;
+      PASS)     PASS=${VALUE} ;;
+      KEY)      KEY=${VALUE} ;;
 			STAT_PORT)    STAT_PORT=${VALUE} ;;
 			STAT_PAGE)    STAT_PAGE=${VALUE} ;;
-			STATS_USER)    STATS_USER=${VALUE} ;;
-            STATS_PASS)    STATS_PASS=${VALUE} ;;
-			SSH_PORT)    SSH_PORT=${VALUE} ;;
-            *)
+			STATS_USER)   STATS_USER=${VALUE} ;;
+      STATS_PASS)   STATS_PASS=${VALUE} ;;
+			SSH_PORT)     SSH_PORT=${VALUE} ;;
+      *)
     esac
 done
 
 if [ ! -d "/var/www/haproxy-wi/app/scripts/ansible/roles/bdellegrazie.haproxy_exporter" ]; then
-	if [ ! -z $PROXY ];then
+	if [[ -n $PROXY ]];then
 		export https_proxy="$PROXY"
 		export http_proxy="$PROXY"
 	fi
 	ansible-galaxy install bdellegrazie.haproxy_exporter --roles-path /var/www/haproxy-wi/app/scripts/ansible/roles/
+	bash -c cat << EOF >> /var/www/haproxy-wi/app/scripts/ansible/roles/bdellegrazie.ansible-role-prometheus_exporter/vars/vars-family-redhat-8.yml
+---
+prometheus_exporter_ansible_packages:
+  - libselinux-python3
+EOF
 fi
 
 export ANSIBLE_HOST_KEY_CHECKING=False
 export ANSIBLE_DISPLAY_SKIPPED_HOSTS=False
 export ACTION_WARNINGS=False
 export ANSIBLE_DEPRECATION_WARNINGS=False
-PWD=`pwd`
+PWD=$(pwd)
 PWD=$PWD/scripts/ansible/
-echo "$HOST ansible_port=$SSH_PORT" > $PWD/$HOST
+echo "$HOST ansible_port=$SSH_PORT" > "$PWD"/"$HOST"
 
 if [[ $KEY == "" ]]; then
-	ansible-playbook $PWD/roles/haproxy_exporter.yml -e "ansible_user=$USER ansible_ssh_pass=$PASS variable_host=$HOST PROXY=$PROXY STAT_PAGE=$STAT_PAGE STAT_PORT=$STAT_PORT STATS_USER=$STATS_USER STATS_PASS=$STATS_PASS SSH_PORT=$SSH_PORT" -i $PWD/$HOST
+	ansible-playbook "$PWD"/roles/haproxy_exporter.yml -e "ansible_user=$USER ansible_ssh_pass=$PASS variable_host=$HOST PROXY=$PROXY STAT_PAGE=$STAT_PAGE STAT_PORT=$STAT_PORT STATS_USER=$STATS_USER STATS_PASS=$STATS_PASS SSH_PORT=$SSH_PORT" -i "$PWD"/"$HOST"
 else	
-	ansible-playbook $PWD/roles/haproxy_exporter.yml --key-file $KEY -e "ansible_user=$USER variable_host=$HOST PROXY=$PROXY STAT_PAGE=$STAT_PAGE STAT_PORT=$STAT_PORT STATS_USER=$STATS_USER STATS_PASS=$STATS_PASS SSH_PORT=$SSH_PORT" -i $PWD/$HOST 
+	ansible-playbook "$PWD"/roles/haproxy_exporter.yml --key-file "$KEY" -e "ansible_user=$USER variable_host=$HOST PROXY=$PROXY STAT_PAGE=$STAT_PAGE STAT_PORT=$STAT_PORT STATS_USER=$STATS_USER STATS_PASS=$STATS_PASS SSH_PORT=$SSH_PORT" -i "$PWD"/"$HOST"
 fi
 
 if [ $? -gt 0 ]
@@ -52,4 +57,4 @@ if ! sudo grep -Fxq "      - $HOST:9101" /etc/prometheus/prometheus.yml; then
 fi
 
 sudo systemctl reload prometheus
-rm -f $PWD/$HOST
+rm -f "$PWD"/"$HOST"
diff --git a/app/scripts/waf.sh b/app/scripts/waf.sh
index 1bff442..32dc042 100644
--- a/app/scripts/waf.sh
+++ b/app/scripts/waf.sh
@@ -2,8 +2,8 @@
 
 for ARGUMENT in "$@"
 do
-    KEY=$(echo $ARGUMENT | cut -f1 -d=)
-    VALUE=$(echo $ARGUMENT | cut -f2 -d=)
+    KEY=$(echo "$ARGUMENT" | cut -f1 -d=)
+    VALUE=$(echo "$ARGUMENT" | cut -f2 -d=)
 
     case "$KEY" in
             PROXY)              PROXY=${VALUE} ;;
@@ -13,10 +13,10 @@ do
     esac
 done
 VERSION=$(echo 2.1.3| awk -F"-" '{print $1}')
-VERSION_MAJ=$(echo $VERSION | awk -F"." '{print $1"."$2}')
+VERSION_MAJ=$(echo "$VERSION" | awk -F"." '{print $1"."$2}')
 
 if (( $(awk 'BEGIN {print ("'$VERSION_MAJ'" < "'1.8'")}') )); then
-	echo 'error: Need HAProxy version 1.8 or later <a title="Close" id="errorMess"><b>X</b></a>'
+	echo 'error: Need HAProxy version 1.8 or later'
 	exit 1
 fi
 
@@ -26,22 +26,26 @@ then
 	export https_proxy="$PROXY"
 fi
 
-if [ -f $HAPROXY_PATH/waf/modsecurity.conf  ];then
-	echo -e 'Info: Haproxy WAF already installed.  <br /><br />'
+if [ -f "$HAPROXY_PATH"/waf/modsecurity.conf  ];then
+	echo -e 'info: Haproxy WAF has already installed.'
 	exit 1
 fi
 if hash apt-get 2>/dev/null; then
 	sudo apt install libevent-dev apache2-dev libpcre3-dev libxml2-dev gcc pcre-devel wget -y
 else
-	sudo yum install -y http://rpmfind.net/linux/centos/7/os/x86_64/Packages/yajl-devel-2.0.4-4.el7.x86_64.rpm >> /dev/null
-	sudo yum install -y http://mirror.centos.org/centos/7/os/x86_64/Packages/libevent-devel-2.0.21-4.el7.x86_64.rpm >> /dev/null
-	sudo yum install -y httpd-devel libxml2-devel gcc curl-devel pcre-devel wget -y >> /dev/null
+  if [[ $(cat /etc/*rele* |grep VERSION_ID |awk -F"\"" '{print $2}') -eq 7 ]]; then
+	  sudo yum install -y http://rpmfind.net/linux/centos/7/os/x86_64/Packages/yajl-devel-2.0.4-4.el7.x86_64.rpm >> /dev/null
+	  sudo yum install -y http://mirror.centos.org/centos/7/os/x86_64/Packages/libevent-devel-2.0.21-4.el7.x86_64.rpm >> /dev/null
+	else
+	  sudo rpm -ivh ftp://ftp.ntua.gr/pub/linux/centos/8.2.2004/PowerTools/x86_64/kickstart/Packages/yajl-devel-2.1.0-10.el8.x86_64.rpm
+	fi
+	sudo yum install -y httpd-devel libxml2-devel gcc curl-devel pcre-devel wget libevent-devel -y >> /dev/null
 fi
 
 wget -O /tmp/modsecurity.tar.gz https://www.modsecurity.org/tarball/2.9.2/modsecurity-2.9.2.tar.gz >> /dev/null
 
 if [ $? -eq 1 ]; then
-	echo -e "Can't download waf application. Check Internet connection"
+	echo -e "Can't download waf application. Check the Internet connection"
 	exit 1
 fi
 cd /tmp
@@ -67,7 +71,7 @@ mv /tmp/modsecurity/INSTALL/include/standalone/* /tmp/modsecurity/INSTALL/includ
 wget -O /tmp/haproxy-$VERSION.tar.gz http://www.haproxy.org/download/$VERSION_MAJ/src/haproxy-$VERSION.tar.gz
 
 if [ $? -eq 1 ]; then
-	echo -e "error: Can't download Haproxy application. Check Internet connection"
+	echo -e "error: Can't download Haproxy application. Check the Internet connection"
 	exit 1
 fi
 cd /tmp
@@ -131,17 +135,17 @@ Include $HAPROXY_PATH/waf/rules/modsecurity_crs_59_outbound_blocking.conf
 Include $HAPROXY_PATH/waf/rules/modsecurity_crs_60_correlation.conf
 EOF
 
-sudo mv /tmp/modsecurity.conf $HAPROXY_PATH/waf/modsecurity.conf 
+sudo mv /tmp/modsecurity.conf "$HAPROXY_PATH"/waf/modsecurity.conf
 wget -O /tmp/unicode.mapping https://github.com/SpiderLabs/ModSecurity/raw/v2/master/unicode.mapping
-sudo mv /tmp/unicode.mapping $HAPROXY_PATH/waf/unicode.mapping
+sudo mv /tmp/unicode.mapping "$HAPROXY_PATH"/waf/unicode.mapping
 wget -O /tmp/owasp.tar.gz https://github.com/SpiderLabs/owasp-modsecurity-crs/archive/2.2.9.tar.gz
 cd /tmp/
 sudo tar xf /tmp/owasp.tar.gz
 sudo mv /tmp/owasp-modsecurity-crs-2.2.9/modsecurity_crs_10_setup.conf.example  $HAPROXY_PATH/waf/rules/modsecurity_crs_10_setup.conf 
-sudo mv /tmp/owasp-modsecurity-crs-2.2.9/*rules/* $HAPROXY_PATH/waf/rules/
-sudo sed -i 's/#SecAction/SecAction/' $HAPROXY_PATH/waf/rules/modsecurity_crs_10_setup.conf 
-sudo sed -i 's/SecRuleEngine DetectionOnly/SecRuleEngine On/' $HAPROXY_PATH/waf/modsecurity.conf
-sudo sed -i 's/SecAuditLogParts ABIJDEFHZ/SecAuditLogParts ABIJDEH/' $HAPROXY_PATH/waf/modsecurity.conf
+sudo mv /tmp/owasp-modsecurity-crs-2.2.9/*rules/* "$HAPROXY_PATH"/waf/rules/
+sudo sed -i 's/#SecAction/SecAction/' "$HAPROXY_PATH"/waf/rules/modsecurity_crs_10_setup.conf
+sudo sed -i 's/SecRuleEngine DetectionOnly/SecRuleEngine On/' "$HAPROXY_PATH"/waf/modsecurity.conf
+sudo sed -i 's/SecAuditLogParts ABIJDEFHZ/SecAuditLogParts ABIJDEH/' "$HAPROXY_PATH"/waf/modsecurity.conf
 sudo rm -f /tmp/owasp.tar.gz
 sudo rm -f /tmp/owasp-modsecurity-crs-2.2.9
 sudo rm -f /tmp/haproxy-$VERSION
@@ -184,8 +188,8 @@ spoe-message check-request
    event on-frontend-http-request
 EOF
 
-sudo mv /tmp/waf.conf $HAPROXY_PATH/waf.conf
-if sudo grep -q "backend waf" $HAPROXY_PATH/haproxy.cfg; then
+sudo mv /tmp/waf.conf "$HAPROXY_PATH"/waf.conf
+if sudo grep -q "backend waf" "$HAPROXY_PATH"/haproxy.cfg; then
 	echo -e "Backend for WAF exists"
 else
 	sudo bash -c 'cat << EOF >> /etc/haproxy/haproxy.cfg
@@ -199,14 +203,14 @@ EOF'
 fi
 
 sudo rm -f /tmp/modsecurity.tar.gz
-sudo rm -rf /tmp/haproxy-$VERSION.tar.gz
+sudo rm -rf /tmp/haproxy-"$VERSION".tar.gz
 
 sudo systemctl daemon-reload
 sudo systemctl enable waf
 sudo systemctl restart waf
 
 if [ $? -eq 1 ]; then
-	echo "error: Can't start Haproxy WAF service <br /><br />"
+	echo "error: Can't start Haproxy WAF service"
     exit 1
 fi
 echo "success"
\ No newline at end of file