Restarting HTTPD Service is not idempotence in nature and also consume more resources suggest a way to rectify this challenge in Ansible playbook

What is idempotency in ansible?

Idempotence is the property of certain operations in mathematics and computer science whereby they can be applied multiple times without changing the result beyond the initial application. This principle enables Ansible to be declarative and yet reliable is idempotence, a concept borrowed from mathematics.

Initially, Apache is not idempotent in nature. This makes apache use more memory and resources every time we run the ansible playbook to configure our web server on the managed node. Because every time we run the ansible playbook it will run the whole process from scratch as it is making it “non-idempotent’’. We can make apache idempotent by using handlers in our ansible playbook in the following manner.

What are Handlers in ansible?

Sometimes you want a task to run only when a change is made on a machine. For example, you may want to restart a service if a task updates the configuration of that service, but not if the configuration is unchanged. Ansible uses handlers to address this use case. Handlers are tasks that only run when notified.

Let’s look into playbook code:-

- hosts: localhost
doc_root : /var/www/abhi
httpd_port: 8081
- name: Installing Webserver
- httpd
- name: Create coustom doc root
path: "{{ doc_root }}"
state: directory
- name: Copy Coustom conf file
dest: "/etc/httpd/conf.d/web.conf"
src: web.conf
notify: restart httpd
- name: Copy the webpage code to doc root
src: index.html
dest: "{{ doc_root }}/index.html"
- name: Start the firewall and enabled
name: firewalld
state: started
- name: firewalld permits access to httpd service port
port: "{{ httpd_port }}/tcp"
permanent: yes
state: enabled
immediate: yes
- name: Start and enable services
name: httpd
state: started
enabled: yes
- name: restart httpd
name: httpd
state: restarted


Listen {{ httpd_port }} 
<VirtualHost {{ ansible_facts['default_ipv4']['address']}}:{{httpd_port}}>
DocumentRoot {{ doc_root }}


<h1>This is test page created by ansible</h1>

Now, Run the playbook

Finally Playbook successfully executed, you can see webserver .

That’s all for this article. Thanks For Reading😊




Love podcasts or audiobooks? Learn on the go with our new app.

Recommended from Medium

How To Securely Manage System Configuration Using AWS

How to do fake migrations in Django?

Create A S3 Bucket To Host a Static Website

Fedora 30 with Linux Surface Kernel

Introducing: greenboot

Enterprises have Big Money to Make by Improving End User Experience

iOS Tampering Techniques Part 2 — Advanced run-time tampering on Swift applications using THEOS

Journey To A Billion Code

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store


More from Medium

Eat that Frog with a Pomodoro

Kristen Stewart: We are pleased to start our today's AMA with #Mecha_Morphing

Second Largest number in an array

Once it’s posted, it’s no longer yours.