Ansible

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Ansible

🌐 Resources 🔗

User Guide - Ansible Community Documentation
jdauphant/awesome-ansible: A collaborative curated list of awesome Ansible resources
ansible-community/awesome-ansible: Awesome Ansible List
Semaphore UI
Blogs:
An Introduction to Configuration Management with Ansible | DigitalOcean
How to Use Ansible: A Reference Guide | DigitalOcean
Ansible Tutorial for Beginners: Playbook & Examples

Ansible Intro

Open-source tool for automation and configuration management
Agentless: Uses SSH or WinRM for communication
YAML-based playbooks for defining configurations
Idempotent: Applies changes without unintended side effects
Modular: Offers built-in modules for various tasks
Roles: Organizes tasks for better reuse and collaboration
Strong community support and extensive documentation

Terminology

Control Node: The system running Ansible, typically on Linux/Unix
Managed Nodes: Target systems controlled by Ansible, requiring SSH and Python (2.6+/3.5+). Supports various OS types, including Windows
Inventory: A file listing managed hosts. Can be static (.ini) or dynamic (JSON output) for project-specific management
Tasks: Units of work executed on managed nodes, either ad-hoc or within playbooks
Playbook: An ordered list of tasks specifying target hosts and execution details, written in YAML
Handlers: Special tasks for managing services, triggered by other tasks and run after all tasks are completed
Roles: Structured collections of playbooks and files for reusable automation packages, streamlining specific deployments

Ansible Install

pipx install --include-deps ansible

pipx ensurepath

# pipx upgrade --include-injected ansible

Generate ansible.cfg file

ansible-config init --disabled > ansible.cfg

Inventory

Even if you do not define any groups in your inventory file, Ansible creates two default groups: all and ungrouped. The all group contains every host. The ungrouped group contains all hosts that don’t have another group aside from all.

sudo mkdir -p /etc/ansible
sudo nano /etc/ansible/hosts

[servers]
ubuntu-srv.local

[all:vars]
ansible_python_interpreter=/usr/bin/python3

Commands

ansible --version
ansible-community --version

ansible-inventory --list -y

# module
ansible all -m ping
ansible all -m setup

# Get info about IPv4 and IPv6 network intefaces
ansible all -m setup -a "filter=*ipv*"

# ad-hoc command
ansible all -a "df -h"
ansible all -a "sudo /bin/apt update"
ansible all -a "uptime"
ansible all -a "tail /var/log/nginx/error.log" --become

# Install latest version of vim, as suoder
ansible all -m apt -a "name=vim state=latest" --become

ansible all -m apt -a "name=tree"

# install asking for password
ansible all -m apt -a "name=nginx" --become -K

ansible all -a "systemctl restart nginx" --become

Labs

Playbooks

mkdir -p $HOME/ansible/playbooks
cd $HOME/ansible/playbooks

nano intro_playbook.yml

---
- hosts: all
  become: true
  tasks:
    - name: Install Packages
      apt: name={{ item }} update_cache=yes state=latest
      loop: [ 'nginx', 'vim' ]
      tags: [ 'setup' ]

    - name: Copy index page
      copy:
        src: index.html
        dest: /var/www/html/index.html
        owner: www-data
        group: www-data
        mode: '0644'
      tags: [ 'update', 'sync' ]

nano index.html

<html>
	<head>
		<title>Testing Ansible Playbooks</title>
	</head>
	<body>
		<h1>Testing Ansible Playbooks</h1>
		<p>This server was set up using an Nginx playbook.</p>
	</body>
</html>

ansible-playbook ./intro_playbook.yml --list-tasks

# Execute the playbook, prompting for sudo password
ansible-playbook ./intro_playbook.yml -K -v

# This will use the current system user as remote SSH user, and the current system user’s SSH key to authenticate to the nodes.

Semaphore UI

Semaphore is a powerful open-source tool for managing Ansible tasks through a web-based interface. This guide demonstrates how to install Semaphore on an Ubuntu Desktop VM using Snap (❗) and configure it for SSH-based Ansible playbooks.

❗ As per Semaphore docs Snap install is deprecated (but still works).
I need to do some testing to integrate Package manager and/or Docker installation documentation.

Install via Snap (Ubuntu Desktop)

# Install Semaphore using Snap
sudo snap install semaphore

# Stop Semaphore (if needed)
sudo snap stop semaphore

# Add an admin user to Semaphore
sudo semaphore user add --admin --login user --name=User --email=user@example.com --password=P@ssw0rd!

# Start Semaphore and view its services
sudo snap start semaphore
sudo snap services semaphore

# Configure SSH for Semaphore
sudo cp $HOME/.ssh/config /root/snap/semaphore/common/sshconfig
chmod 644 /root/snap/semaphore/common/sshconfig

Install via Docker
Not tested
Follow the steps outlined in the official Semaphore documentation for Docker-based deployment. Use the container configurator to get the ideal Docker configuration for Semaphore.
Here is a summary for convenience to deploy via docker with data persistence:
docker run --name semaphore \
-p 3000:3000 \
-e SEMAPHORE_DB_DIALECT=bolt \
-e SEMAPHORE_ADMIN=admin \
-e SEMAPHORE_ADMIN_PASSWORD=changeme \
-e SEMAPHORE_ADMIN_NAME="Admin" \
-e SEMAPHORE_ADMIN_EMAIL=admin@localhost \
-v semaphore_data:/var/lib/semaphore \
-v semaphore_config:/etc/semaphore \
-v semaphore_tmp:/tmp/semaphore \
-d semaphoreui/semaphore:latest
Missing .ssh/config setup

Post-install configuration

Log In
- Access Semaphore at http://localhost:3000
- Use the admin credentials set during the setup process
Keystore Configuration
- Add the SSH keys + passphrases for secure connections
Repository Configuration
- Link the Git repository using SSH credentials
- e.g. - git@github.com:syselement/ansibletest.git
Environment
- Set up an empty environment
Static Inventory Configuration
- Define an inventory file with host and group details
- e.g.

[pihole]
pihole.lan.syselement.com

[ubuntu]
ubuntu-srv.lan.syselement.com

[all:vars]
ansible_ssh_common_args = '-F /root/snap/semaphore/common/sshconfig'

Creating Ansible Task Templates

Task templates in Semaphore point to Ansible playbooks stored in the repository. Here’s how to set them up:

Organize the repository
- Structure the repository to store playbooks logically.
- e.g.

ansible/
├── playbooks/
│   ├── updatelinux.yaml
│   ├── deployweb.yaml
└── roles/
    ├── common/
    ├── webserver/

Create a template in Semaphore
- Add a new Task Template in Semaphore
  - e.g.
  - Name - AptUpdateUbuntu
    Playbook Path - Relative path to the playbook - ansible/playbooks/updatelinux.yaml