Configuring HaProxy and Web server using Ansible

What is Ansible?

Ansible is a simple open-source IT engine that automates application deployment, intra- service orchestration, cloud provisioning, and many other IT tools.

Ansible is easy to deploy because it does not use any agents or custom security infrastructure.

Ansible uses playbook to describe automation jobs, and playbook uses very simple language i.e. YAML (It’s a human-readable data serialization language & is commonly used for configuration files, but could be used in many applications where data is being stored)which is very easy for humans to understand, read and write. Hence the advantage is that even the IT infrastructure support guys can read and understand the playbook and debug if needed (YAML – It is in human-readable form).

What is Load Balancer?

Load balancing is a key component of highly available infrastructures commonly used to improve the performance and reliability of websites, applications, databases, and other services by distributing the workload across multiple servers.

Task:-

 🔰 Install haproxy and httpd in respective nodes

 🔰 Configure haproxy

 🔰 Start the service of Haproxy

 🔰 Create web page

 🔰 Start web server services

Solution:-

- hosts: localhost
  tasks:
          - name: "Installing haproxy"
            package:
                    name: "haproxy"
                    state: present


          - name: "Copying configuration file"
            template:
                    src: "haproxy.cfg"
                    dest: "/etc/haproxy/haproxy.cfg"


          - name: "starting haproxy services"
            service:
                    name: "haproxy"
                    state: started




- hosts: webserver 
  tasks:
          - name: "Installing httpd"
            package:
                    name: "httpd"
                    state: present
          - name: "copying webpage"
            copy:
                    content: "hi from {{ ansible_facts['hostname'] }}"
                    dest: "/var/www/html/index.html"
          - name: "starting httpd services"
            service:
                    name: "httpd"
                    state: restarted
                   

We have to copy the template haproxy.cfg after doing the following changes

#---------------------------------------------------------------------
# Example configuration for a possible web application.  See the
# full configuration options online.
#
#   https://www.haproxy.org/download/1.8/doc/configuration.txt
#
#---------------------------------------------------------------------


#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
    # to have these messages end up in /var/log/haproxy.log you will
    # need to:
    #
    # 1) configure syslog to accept network log events.  This is done
    #    by adding the '-r' option to the SYSLOGD_OPTIONS in
    #    /etc/sysconfig/syslog
    #
    # 2) configure local2 events to go to the /var/log/haproxy.log
    #   file. A line like the following can be added to
    #   /etc/sysconfig/syslog
    #
    #    local2.*                       /var/log/haproxy.log
    #
    log         127.0.0.1 local2


    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon


    # turn on stats unix socket
    stats socket /var/lib/haproxy/stats


    # utilize system-wide crypto-policies
    ssl-default-bind-ciphers PROFILE=SYSTEM
    ssl-default-server-ciphers PROFILE=SYSTEM


#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
    mode                    http
    log                     global
    option                  httplog
    option                  dontlognull
    option http-server-close
    option forwardfor       except 127.0.0.0/8
    option                  redispatch
    retries                 3
    timeout http-request    10s
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout http-keep-alive 10s
    timeout check           10s
    maxconn                 3000


#---------------------------------------------------------------------
# main frontend which proxys to the backends
#---------------------------------------------------------------------
frontend main
    bind *:8080
    acl url_static       path_beg       -i /static /images /javascript /stylesheets
    acl url_static       path_end       -i .jpg .gif .png .css .js


    use_backend static          if url_static
    default_backend             app


#---------------------------------------------------------------------
# static backend for serving up images, stylesheets and such
#---------------------------------------------------------------------
backend static
    balance     roundrobin
    server      static 127.0.0.1:4331 check


#---------------------------------------------------------------------
# round robin balancing between the various backends
#---------------------------------------------------------------------
backend app
    balance     roundrobin
{% for hosts in groups['webserver'] %}
    server  app1  {{ hosts }}:80  check
{% endfor %}

Run the code using the command below

ansible-playbook lb-webserver.yml

After successful execution, you will see below output:-

By going to the IP and port number of the Load balancer we can see our website

By refreshing the page we can see the hostname is changing. Hence Load balancer and Webserver are configured successfully.

That's all!!

For any queries or suggestions feel free to mail me at: akashtiwari370@gmail.com

For the complete code check my GitHub