Learn how to automate Raspberry Pi setup with Ansible. The Raspberry Pi is a tiny and affordable computer that you can use to learn, test and experiment concepts about distributed computing. The first challenge is always how to keep the Rasbperry Pi’s up to date. Having four Rasbperry Pi seems manageable, but If you have more than 4 Rasbperry Pi, you'll need an automation tool like Ansible to automate repetitive task like installing, updating software on your Rasbperry Pi’s.

In this brief tutorial, I'll walk you through the basics of Ansible using a cluster of four Raspberry Pi.

• Ansible Installation
  • Install Ansible on Mac
  • Test Ansible on Localhost
  • Configure your macOS /etc/hosts for Ansible
  • Enable Passwordless SSH access for ansible
  • Configure Ansible /etc/ansible/hosts
    • Ansible playbook to ping all server
    • Check python version with ansible
• YAML Basics
• Ad hoc Commands
• Ansible Inventory
• Ansible Playbooks
• Ansible Roles
• Ansible Variables
• Advanced Execution
• Ansible Vault
• Ansible Container
• Troubleshooting
• Ansible Books and courses
• Additional Resources

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The best way to get started on a macOS is to use Homebrew. If you already have Homebrew installed, you can install ansible by running the following command

brew install ansible

If you don't already have Homebrew installed, I would strongly recommend that you install it! It's incredibly useful for installing software dependencies like OpenSSL, MySQL, Postgres, Redis, SQLite, and more.

You can install it by running the following command:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

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Run the following command:

ansible localhost -m ping

localhost | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

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1. Open your terminal, type this command:

sudo nano /etc/hosts

2. Add 192.168.1.x to end of the /etc/hosts file.

# Raspberry Pi
192.168.1.6		raspi1    
192.168.1.7		raspi2
192.168.1.8		raspi3
192.168.1.9		raspi4

3. To save your changes, press Ctrl+x on your keyboard.

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In order to fully control a remote machine we need to be able to execute command on the remote machines as user root.

To enable passwordless sudo:

1. Log in to the Raspberry Pi command-line interface. The default user name and password of the Raspberry Pi hardware are pi and raspberry, respectively.

2. In the command-line interface, type this command:

sudo nano /etc/sudoers.d/010_pi-nopasswd

3. Enable passwordless sudo access by adding this line:

<user name> ALL=(ALL) NOPASSWD: ALL

For example, to provide passwordless sudo access to a user pi, type:

pi ALL=(ALL) NOPASSWD: ALL

4. To save your changes, press Ctrl+x on your keyboard.

5. For these changes to take effect, restart Raspberry Pi by typing this command:

sudo reboot

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1. Open your terminal, type this command create /etc/ansible/hosts directory

sudo mkdir -p /etc/ansible

2. Add hostname to /etc/ansible/hosts file.

[gui]
raspi1 
raspi2 

[nogui]
raspi3 
raspi4 

You also can define ‘host list’ with ranges

[gui]
raspi[1:2]

[nogui]
raspi[3:4]

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ansible -m ping all

raspi2 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
raspi1 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
raspi4 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
raspi3 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

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ansible -m shell -a 'python -V' gui

raspi1 | CHANGED | rc=0 >>
Python 2.7.13

raspi2 | CHANGED | rc=0 >>
Python 2.7.13

ansible -m shell -a 'python -V' all

raspi3 | CHANGED | rc=0 >>
Python 2.7.13

raspi4 | CHANGED | rc=0 >>
Python 2.7.13

raspi1 | CHANGED | rc=0 >>
Python 2.7.13

raspi2 | CHANGED | rc=0 >>
Python 2.7.13

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