SSH & Ansible

Terminology

VM      : Virtual machine

Host   : Controller

Guest/remote : Client machine

SSH     : Secure Shell

Inventory file: A text file that stores nodes' info

Prerequisites

1. At least 2 vms running

2. Any text editor

3. Terminal (coz it's awesome)

What is SSH?

A service that allows very strong authentication and encrypted data communication.

Let's start

1. Install openssh-client in remotes and Install openssh-server in the host

  $sudo dnf install -y openssh-server

  $sudo dnf install -y openssh-client

2. Enable and start the services

  $sudo systemctl enable sshd

  $sudo systemctl start sshd

...keep going...

4. Create public and private keys

   $sudo ssh-keygen

5. login remote from host by

   $sudo ssh root@192.168.X.X //ip address of remote

6. Exit and copy your public to remote

   $sudo ssh-copy-id root@<ip>

7. Try to login again, If everything worked fine, it should not ask for password.

What is Ansible?

A software that enables us to deploy any application on multiple computers at once.

Agentless

Easy to use

Intelligent automation system

Need not be installed on client machines

Open Source

Ansible is...

Its major functions

Change Management

Automation

Provisioning

Orchestration

Let's install Ansible

1. Install ansible on controller

$sudo dnf install -y ansible

on the path..

• ansible's config file can be found in /etc/ansible
• Inventory file is stored in /etc/ansible/hosts
• Go to the end of file, and make a group of nodes.

on the path..

An example of group

   [web-servers]
   192.168.X.X
   192.168.X.X

You can add any number of guests

Test your connection.

 #ansible -m ping amrita

Hack on

 #ansible -m command -a "uptime" amrita

Playbooks

Playbooks

Playbooks