Varnish and nginx on Centos 7

yum install varnish
yum install nginx

Config nginx listen on port 8081

server {
        listen 8081;
        rewrite ^(.*)$1 permanent;
server {
        listen 8081 default_server;



  • Config varnish: vi /etc/varnish/default.vcl (for wordpress)
# This is an example VCL file for Varnish.
# It does not do anything by default, delegating control to the

Configure rsyslogd on centos 7 as remote syslog server


echo "\$ModLoad imudp" > /etc/rsyslog.d/server.conf
echo "\$UDPServerRun 514" >> /etc/rsyslog.d/server.conf
echo "\$ModLoad imtcp" >> /etc/rsyslog.d/server.conf
echo "\$InputTCPServerRun 514" >> /etc/rsyslog.d/server.conf
echo "\$PreserveFQDN on" >> /etc/rsyslog.d/server.conf

yum -y install rsyslog-gnutls rsyslog-mysql rsyslog-crypto

MySQL/MariaDB database configuration

Assuming MariaDB is already installed and running.

rsyslog centos7

Maxscale and pacemaker on centos 7

Install packages on both nodes

sudo yum install corosync pcs pacemaker maxscale

Set the password for the hacluster user [both nodes]

sudo passwd hacluster

Start the pcs daemon service [both nodes]

sudo systemctl start pcsd

Authenticate the cluster

sudo pcs cluster auth node01.domain.local node02.domain.local

Create cluster

Install RabbitMQ on centos 7

Install RabbitMQ on CentOS 7

sudo yum -y install epel-release
sudo yum -y update

Install Erlang

Download repository


Add repository

sudo rpm -Uvh erlang-solutions-1.0-1.noarch.rpm

Install erlang and dependencies

sudo yum -y install erlang socat logrotate

Install RabbitMQ

Download RabbitMQ package

rabbitmq centos7

Apache run external program with SELinux enabled

This is helpful when you don't want to disable Selinux and need to run external program like wkhtmltopdf via apache on selinux enabled. Run the following commands from the terminal. (This has been tested in CentOS 7)

Allow Execution

setsebool httpd_execmem on

Change a dirs security context if the program writes to a file

chcon -R -t httpd_sys_rw_content_t dir
apache selinux