Ansible:

References:

https://sysadmincasts.com/episodes/43-19-minutes-with-ansible-part-1-4

https://sysadmincasts.com/episodes/45-learning-ansible-with-vagrant-part-2-4

Installation:

sudo apt-get update
sudo apt-get install software-properties-common
sudo apt-add-repository ppa:ansible/ansible
sudo apt-get update
sudo apt-get install ansible

Ref:

http://docs.ansible.com/ansible/latest/intro_installation.html#latest-releases-via-apt-ubuntu

Version check:

cloud@vm1:~$ ansible --version
ansible 2.4.2.0
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/home/cloud/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/dist-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.6 (default, Oct 26 2016, 20:30:19) [GCC 4.8.4]
cloud@vm1:~$

Configuration:

/etc/ansible/ansible.cfg

[defaults]
inventory      = /etc/ansible/hosts

/etc/ansible/hosts

[web]
10.0.1.5
10.0.1.4

Testing :

Run ansible ping command to check the SSH Reachability of the hosts:

ansible [all | host| group] -m ping --user <remote user> --private-key <keyfile> --ask-pass<password>

cloud@vm1:~$ ansible web -m ping --private-key mykey.private 
10.0.1.4 | SUCCESS => {
    "changed": false, 
    "ping": "pong"
}
10.0.1.5 | SUCCESS => {
    "changed": false, 
    "ping": "pong"
}
cloud@vm1:~$

Simple playbook execution:

Ref: https://github.com/jweissig/episode-45

This playbook install a public key in the remote machine. The public key is located in /home/cloud/.ssh/id_rsa.pub file. (if you dont have, create one using "ssh-keygen -t rsa -b 2048" command.

Playbook file:

---
- hosts: all
  sudo: yes
  gather_facts: no
  remote_user: cloud

  tasks:

  - name: install ssh key
    authorized_key: user=cloud
                    key="{{ lookup('file', '/home/cloud/.ssh/id_rsa.pub') }}" 
    state=present

Running the command:

ansible-playbook examples/e45-ssh-addkey.yml --private-key mykey.private

Log:

cloud@vm1:~$ ansible-playbook examples/e45-ssh-addkey.yml --private-key mykey.private 
[DEPRECATION WARNING]: Instead of sudo/sudo_user, use become/become_user and make sure become_method is 'sudo' (default). This
 feature will be removed in version 2.6. Deprecation warnings can be disabled by setting deprecation_warnings=False in 
ansible.cfg.

PLAY [all] ********************************************************************************************************************

TASK [install ssh key] ********************************************************************************************************
changed: [10.0.1.5]
changed: [10.0.1.4]

PLAY RECAP ********************************************************************************************************************
10.0.1.4                   : ok=1    changed=1    unreachable=0    failed=0   
10.0.1.5                   : ok=1    changed=1    unreachable=0    failed=0