Install Ansible on linux instance and connect to your hosts

Ansible

Ansible is an open-source software provisioning, configuration management, and application-deployment tool enabling infrastructure as code.

its a deployment tool. this tool is part of ci/cd pipeline

Ansible Nodes

In Ansible, there are two categories of computers: The control node and managed nodes. The control node is a computer that runs Ansible. There must be at least one control node, although a backup control node may also exist. A managed node is any device being managed by the control node.

Ansible playbook

 An Ansible playbook is a blueprint of automation tasks—which are complex IT actions executed with limited or no human involvement. Ansible playbooks are executed on a set, group, or classification of hosts, which together make up an Ansible inventory.

In this article i am going to explain how to configure ansible control node and managed nodes.

1. Ansible Package installation (Control Node)

First we are going to update the server.

sudo yum update -y

and get the epel rpm file and install that.

wget http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

sudo yum install epel-release-latest-7.noarch.rpm -y

and again update the server.

sudo yum update -y

now we are going to install openssl,ansible and git.

sudo yum install git python python-devel python-pip openssl ansible -y

check ansible version.

ansible --version

create ansible user in server

sudo useradd ansible

sudo passwd ansible

To setup paswordless sudo execute the below command.

echo "ansible ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/ansible

then edit the ssh config file using the below location.

sudo vi /etc/ssh/sshd_config

Then restart the ssh service

sudo service sshd restart

Now we want to edit ansible.cfg file

1.uncomment inventry file location

2.add the below line before inventory line

command_warnings=False

interpreter_python=auto_silent

3.and uncomment sudo_user line.

sudo_user = root

2.Ansible Managed Node Configuration

Now we will configure nodes that will be managed by ansible.

I will going to add two servers as ansible nodes.

create ansible user in node

sudo useradd ansible

sudo passwd ansible

To setup passwordless sudo execute the below command.

echo "ansible ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/ansible

Then edit the ssh config file using the below location.

sudo vi /etc/ssh/sshd_config

Then restart the ssh service

sudo service sshd restart

ok all set in client nodes.

Server IP = 172.31.0.45

Client IP = 172.31.34.61 and 172.31.39.124

now ssh from server to client node

its asking password.

after enter password its working.

so now we are going to set without asking pasword state using ssh keygen method.

In the ansible server node type the below command

ssh-keygen

its asking some question. just press enter three times.

the key is genrated.

now we want to copy the ssh key to our client nodes.

Syntax ssh-copy-id username@ip

ssh-copy-id  ansible@172.31.34.61

ssh-copy-id  ansible@172.31.39.124

execute the above command its asking user password. enter it.

now check with ssh to the client with out apssword.

ssh ansible@172.31.34.61

ssh ansible@172.31.39.124

its working perfectly.

Add ansible client node ip in ansible server host config file.

in ansible server edit hosts file

sudo vi /etc/ansible/hosts

Now check the ansible server client connection status.

execute the below command.

ansible all -m ping

yeah finally its get conected all nodes from server without asking any password.

PING PONG

3. Ansible Playbook creation

Create playbook and install service in clients nodes from server

and add the below content to the playbook

---
- name: install httpd 
  hosts: servers
  become: true

  tasks:
      - name: ensure apache is at the latest version
        yum:
          name: httpd
          state: latest
      - name: ensure apache is running
        service:
          name: httpd
          state: started