8 September 2023
Ansible has rapidly become one of the most popular open source automation tools used by system administrators around the world. This Agentless configuration management and automation platform allows sysadmins to simplify their workflows, manage IT infrastructure efficiently, and amplify productivity.
Learning Ansible as a sysadmin is a surefire way to supercharge your skillset. Ansible's intuitive workflows make it easier than ever to automate common sysadmin tasks. All of this material can be found on our Ansible Training Course.
In this complete guide, you'll learn:
By the end, you'll have the knowledge to start leveraging Ansible for automation, saving time and unlocking new capabilities as a sysadmin.
Let's get started!
Ansible is an open source automation platform, provided by Red Hat, that allows sysadmins to manage configurations, provision infrastructure, deploy applications, and orchestrate advanced IT processes.
Here are some key characteristics of Ansible:
These attributes make Ansible a versatile choice for anything from configuring a few servers to managing complex enterprise infrastructure. Next, let's look at why Ansible is so valuable for sysadmins.
There are many excellent reasons why Ansible should be part of every sysadmin's toolbox. Here are some of the top benefits of using Ansible:
Ansible playbooks allow you to codify and automate complex, multi-tier processes with orchestration. You can sequence ordered tasks, conditionally execute steps, and prompt for user input as needed.
For example, you could automate an intricate multi-machine deployment process for a clustered application.
Ansible lets you define infrastructure specifications, configurations, and automations in simple YAML playbooks. These playbooks can then be treated like version-controlled source code.
This infrastructure-as-code approach leads to consistent, repeatable, and testable infrastructure management.
Ansible is a powerful configuration management tool. Playbooks can automate OS provisioning, software installation, security hardening, resource configuration and more.
Ansible ensures all your systems are kept in the desired state and compliant with baselines.
Deploying apps like websites, databases, custom services, etc. can be complex. Ansible provides extensive tools for automating deployments.
You can orchestrate rolling updates, create resource tiers, manage dependencies, and automate zero downtime deployments.
When sysadmin tasks are codified into playbooks, more time can be spent on higher value work. Ansible lets you do more with less while reducing mistakes.
Ansible also makes it easy for new team members to quickly become productive based on existing playbooks.
As you can see, Ansible delivers huge value by augmenting a sysadmin's skillset. Now let's look at how to actually get started with Ansible.
Ansible can be installed on Linux (RHEL, CentOS, Ubuntu), macOS, and Windows systems. We'll cover installation steps for CentOS and Ubuntu Linux here.
To follow along, you will need:
On CentOS or RHEL, install Ansible using yum:
sudo yum install ansible
To confirm, check the version:
ansible --version
For Ubuntu, use apt to install Ansible:
sudo apt update sudo apt install ansible
Check that Ansible is installed:
ansible --version
This installs Ansible on the control node. Managed nodes do not need any extra software installed.
Next, we'll cover some key Ansible configuration like the hosts inventory and configuration file.
The Ansible inventory specifies the managed nodes that playbooks will run against. This is defined in a file (default /etc/ansible/hosts) with a simple INI-like format:
[webservers] web1.example.com web2.example.com [dbservers] db1.example.com db2.example.com
Individual nodes or groups like [webservers] and [dbservers] can be specified. The location of the inventory can be configured in ansible.cfg. Dynamic inventory sources can also be used instead of static files.
Global Ansible settings are specified in /etc/ansible/ansible.cfg. Common options to configure include:
inventory - Path to the Ansible inventory fileroles_path - Path to the Ansible roles directoryremote_user - Default SSH user name for managing nodesask_pass - Ask for SSH passwords when neededWith Ansible installed and configured, we can move on to running ad-hoc commands.
Ansible ad-hoc commands allow you to execute one-off tasks on remote nodes without having to write a full playbook. They are useful for quickly doing simple automation and system administration tasks.
Here is the syntax for ansible ad-hoc commands:
ansible [pattern] -m [module] -a "[module options]"
pattern is the inventory hosts to run against, like webservers-m specifies the module (action plugin) to execute-a are arguments passed to the moduleFor example, to reboot all nodes in the [webservers] group:
ansible webservers -m reboot -a
Some useful modules for ad-hoc commands include:
ping - Test connectivity to nodescommand - Execute commands on remote nodesshell - Execute shell commands on remote nodesapt - Install/remove Debian packagesyum - Install/remove RPM packagesservice - Manage servicesAd-hoc commands let you easily perform one-off automation. But Ansible really excels when you orchestrate tasks using playbooks.
Ansible playbooks are files written in YAML format that define automation policies and orchestrate tasks. They provide a repeatable, consistent way to configure systems and deploy software.
A playbook contains:
apt, copy, template, etc. that are called by tasksHere is a simple Ansible playbook example:
--- - name: Install and configure webserver hosts: webservers vars: http_port: 80 max_clients: 200 tasks: - name: Install Apache apt: name: apache2 state: latest - name: Copy index.html file template: src: index.html dest: /var/www/html - name: Restart Apache service: name: apache2 state: restarted handlers: - name: restart apache service: name: apache2 state: restarted
This playbook does the following:
Playbooks like this can be executed like:
ansible-playbook configure-webservers.yml
Now let's explore some more advanced playbook features.
Ansible offers many powerful directives for writing sophisticated playbooks. Here are some highlights:
Variables store values that can be substituted into playbooks and referenced as {{ variable_name }}.
They allow parameterizing playbooks so values can be injected at runtime.
when statements let you conditionally control whether tasks run based on variables, facts, or other tests:
tasks: - name: Install PostgreSQL apt: name: postgresql when: pg_install | bool
Loops iterate over a list variable to minimize repetition in playbooks:
vars: users: - alice - bob - charlie tasks: - name: Create users user: name: "{{ item }}" loop: "{{ users }}"
Templates combine variables with file contents. Ansible will replace all {{ variables }} in a template file before copying to nodes.
Roles are ways to group tasks, variables, templates and modules together into reusable units. This helps keep large playbooks organized.
We've covered the key capabilities you need to start being productive with Ansible as a sysadmin. Now let's look at how to apply Ansible to common sysadmin and infrastructure tasks.
Ansible makes it easy to automate manual, repetitive sysadmin work.
Here are some examples of applying Ansible to simplify common sysadmin responsibilities:
Provision bare metal and cloud servers by installing the OS, standard packages, configuring users, hardening security policies, and more:
- name: Provision server hosts: all roles: - base - security - users
Manage system configurations like sudo policies, cron jobs, log settings, users/groups, and much more:
- name: Apply system configuration hosts: webservers tasks: - name: Set sudo policies copy: src: sudoers dest: /etc/sudoers - name: Add sysadmin user user: name: bob groups: wheel
Deploy apps across clusters of servers, orchestrating rolling updates, managing dependencies, creating resources, and automating zero downtime deployments:
- name: Deploy application hosts: appservers roles: - { role: common, tags: common } - { role: database, tags: database } - { role: webserver, tags: webserver } - { role: queue, tags: queue } - { role: app, tags: app }
Proactively scan for and remediate configuration drift to ensure servers adhere to baseline standards:
- name: Detect and remediate configuration drift hosts: all tasks: - name: Scan for non-compliant configurations command: /usr/bin/compliance-scanner - name: Reapply baseline configuration import_role: name: config_baseline
And many more use cases! Ansible provides modules covering virtually every sysadmin need from storage administration to network device configuration.
In this article, we covered the benefits of learning Ansible as a sysadmin and walked through core concepts like:
Ansible delivers immense value for sysadmins through powerful, human-readable automation.
To take your Ansible skills to the next level:
As you gain experience with Ansible, you'll be able to streamline and scale more aspects of systems administration. Ansible lets you work smarter, open up new career opportunities, and focus on more impactful work - making it an indispensable tool for any ambitious sysadmin.
Ansible is primarily written in Python and takes advantage of Python libraries. However, Ansible playbooks use YAML format, which is easier for humans to read and write compared to JSON or XML.
No agents are needed on remote nodes managed by Ansible. It uses native OpenSSH on Linux and WinRM on Windows servers to connect and execute tasks.
Yes, Ansible has extensive network automation capabilities through Ansible Network modules. It can manage network gear from vendors like Cisco, Juniper, Arista and more.
Absolutely. Ansible integrates smoothly with AWS, Azure, Google Cloud, OpenStack, and more. It can provision infrastructure, orchestrate deployments, and manage configurations across cloud environments.
Ansible is used by many organizations to automate infrastructure at massive scales. Ansible control nodes can be scaled out, playbook execution parallelized, and workflows distributed. Ansible is a powerful option for enterprise automation.
If you enjoyed this article you might enjoy our first article Ansible for Beginners: A Comprehensive Guide to Get Started with IT Automation
In the world of DevOps and automation, Ansible plays a pivotal role in orchestrating and managing IT infrastructure efficiently. At JBI Training, we offer a selection of courses to empower you with the skills required to excel in Ansible and DevOps practices.
Enroll in these courses and equip yourself with the knowledge and tools to navigate the world of Ansible automation and DevOps. Learn to streamline operations, accelerate software delivery, and foster collaboration between development and operations teams.
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