Ansible¶

Overview¶

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Ansible automates the management of remote systems and controls their desired state.

Ansible provides open-source automation that reduces complexity and runs everywhere. Using Ansible lets you automate virtually any task. Here are some common use cases for Ansible:

Eliminate repetition and simplify workflows
Manage and maintain system configuration
Continuously deploy complex software
Perform zero-downtime rolling updates

Ansible uses simple, human-readable scripts called playbooks to automate your tasks. You declare the desired state of a local or remote system in your playbook. Ansible ensures that the system remains in that state.

As shown in the preceding figure, most Ansible environments have three main components:

Control node

A system on which Ansible is installed. You run Ansible commands such as ansible or ansible-inventory on a control node.

Inventory

A list of managed nodes that are logically organized. You create an inventory on the control node to describe host deployments to Ansible.

Managed node

A remote system, or host, that Ansible controls.

Initial Setup¶

This will cover the installation and structure required for using Ansible efficiently.

Ansible be run from one computer (control node) to manage the configuration of multiple other servers (mananged nodes).

This requires a few things to work.

SSH Keys¶

Generate an SSH on the control node. Add a passphrase, this is your main, secure key.

ssh-keygen -t ed25519 -C "controlhostname"

Copy that SSH key to the mananged node(s).

ssh-copy-id -i ~/.ssh/id_ed25519.pub <IP Address>

Generate an SSH key that is specifically for Ansible. No passphrase. This is ansible specific key.

ssh-keygen -t ed25519 -C "ansible"

Copy that SSH key to the mananged node(s).

ssh-copy-id -i ~/.ssh/ansible.pub <IP Address>

Connecting using an SSH key.

ssh -i .ssh/<key_name> <IP Address>

Cache the passphrase

eval $(ssh-agent)
ssh-add

Bash alias for caching the passphrase

alias ssha='eval $(ssh-agent) && ssh-add'

Git Repository¶

Check if git is installed

which git
# This will return `/usr/bin/git` if installed.

Install git

sudo apt update
sudo apt install git

Create user config for git

git config --global user.name "First Last"
git config --global user.email "somebody@somewhere.net"

Check the status of your git repository

git status

Stage the README.md file (after making changes) to be included in the next git commit

git add README.md

Set up the README.md file to be included in a commit

git commit -m "Updated readme file, initial commit"

Send the commit to Github

git push origin master