Ansible : An Automation Engine

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Ansible : An Automation Engine

Postby admin » Mon May 15, 2017 12:16 pm

Ansible is an open source automation engine. With ansible it is possible to perform application deployment, intra service orchestration, cloud provisioning and more over it is a configuration management tool. Ansible is acquired by Redhat and is included as a part of fedora and is also available for redhat enterprise Linux as well as for other operating systems

Ansible is super easy to setup and it just requires to install a package ansible in the controlling machine. The users can setup the ansible inventory where the nodes to be managed are listed. Ansible defines a property called playbooks which works as scripts, it is pushed to one or every nodes and executed. Playbooks are written in yaml script and the connections are by default made through ssh. Ansible comes loaded with a library of modules which can be executed directly or through playbooks and if needed the users can define one of their own. Ansible also provides plugins and api's which could be handy when put to the production environment. The major factor that makes ansible different from any of its kind is its agentless architecture. The agentless architecture requires no programs to be installed and no background daemons to run in the nodes to make connection with the control machine.

Ansible installation on Redhat Enterprise Linux 7

sudo rpm -i epel-release-latest-7.noarch.rpm

After installing EPEL, you need to update your package list.

sudo yum update

And that’s it! Now install Ansible

sudo yum install ansible

To ping your Ansible server on localhost. You should receive a “pong” in response.

ansible localhost -m ping

Ansible’s inventory file defaults to the location /etc/ansible/hosts

The format for /etc/ansible/hosts looks like this:



The headings in brackets are group names, which are used in classifying systems and deciding what systems you are controlling at what times and for what purpose.

Ansible playbook example:

-hosts: webservers
- name: Installs nginx web server
yum: pkg=nginx state=installed update_cache=true
- start nginx

- name: Upload default index.html for node
copy: src=static_files/index.html dest=/usr/share/nginx/www/ mode=0644

- name: start nginx
service: name=nginx state=started

• /etc/ansible — The main configuration folder
• /etc/ansible/hosts — This file holds information for the hosts/and host groups you will configure
• /etc/ansible/ansible.cfg — The main configuration file for Ansible
• /etc/ansible/roles — This folder allows you to create folders for each server role.
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