Ansible Modules | Overview.

An Overview of Ansible Modules

Focus:

• Tailored for Devop, DevSecOps,Cloud Engineers.

Breakdown:

• Intro,
• Key Aspects of Ansible modules,
• The Concept:  Ansible Modules,
• Types of Ansible Modules (scripts),
• Key Features of Ansible Modules (scripts),
• Sample of  Ansible Modules (scripts) in a Playbook,
• Popular Ansible Modules (scripts),
• Using Ansible Modules in DevOps,
• Insights.

Intro:

• Ansible modules are scripts (small programs) usually written in Python, that perform specific tasks or actions on managed hosts, APIs, or the local machine. 
• Ansible modules are the building blocks of Ansible automation and are called directly within playbooks to execute tasks
• In DevOps, Ansible is a popular open-source automation tool used for configuration management, application deployment, and task automation.
• One of the key components that make Ansible powerful is its modules. 
• Ansible modules are reusable, standalone units of code (scripts or playbooks)  that perform specific tasks, such as installing software, managing services, or configuring systems.

Key Aspects of Ansible modules

Functionality:

•  Each module is designed to perform a single, atomic task, such as managing users (ansible.builtin.user), copying files (ansible.builtin.copy), or managing lines in a text file (ansible.builtin.lineinfile).

Execution:

•  When a playbook runs, Ansible executes the module on the target host, and once the task is complete, the module exits.

Idempotency:

•  Many modules are designed to be idempotent, meaning they ensure the system is in a desired state without making changes if the state is already correct. This simplifies automation by preventing unintended modifications on repeated runs.

Collections:

• Modules are organized into collections. Modules in ansible-core use the ansible.builtin identifier (e.g., ansible.builtin.debug). Many others are available through Ansible Galaxy.

Documentation:

•  twtech can learn about available modules and their options using the command line tool ansible-doc or by consulting the official Ansible documentation.

Custom Development:

•  If a built-in or community module does not meet specific needs, developers can write their own custom modules, typically in Python. 
• In essence, playbooks define the automation workflow, while modules are the tools that carry out the actual work

The Concept:  Ansible Modules

• Ansible modules are scripts that define a specific task or action that Ansible can execute. 
• Ansible modules provide the actual functionality and are the building blocks of Ansible playbooks (which define a set of tasks to be run on managed hosts). 
• Ansible modules allow twtech to automate complex tasks across its infrastructure in a simple, idempotent, and declarative way.
• Each Ansible module is designed to perform a specific task and returns a standardized output.
• Modules (scripts) are written in various programming languages like Python, but they abstract away the complexity, making them simple to use without requiring deep programming knowledge.

Types of Ansible Modules

There are many types of Ansible modules, each designed to handle different tasks in twtech DevOps workflow. Some key categories include:

1. System Modules:
• Used to manage system configurations, packages, users, services, and more.
• Example modules: user, package, service, file, group, cron.
2. Cloud Modules:
• These modules allow you to manage cloud resources across various cloud providers like AWS, …
• Example modules: ec2…
3. Network Modules:
• Used to configure and manage network devices, such as routers, switches, firewalls, and load balancers.
• Example modules: ios_config, nxos_config, juniper_junos.
4. Database Modules:
• Manage databases, users, permissions, and other database-related tasks.
• Example modules: mongodb_user, mysql_db, postgresql_user.
5. Security Modules:
• These modules are designed for managing security-related tasks, such as handling SSH keys, configuring firewalls, or managing encryption.
• Example modules: firewalld, authorized_key, ufw.
6. Deployment Modules:
• Focus on tasks related to application deployment and orchestration.
• Example modules: git, docker_container, k8s, template.
7. Monitoring and Logging Modules:
• Used to configure and interact with monitoring tools, log aggregation systems, and notification services.
• Example modules: cloudwatch, slack, syslog.

Key Features of Ansible Modules (scripts)

Idempotency:

• Ansible modules are idempotent, meaning that running the same task multiple times will not cause any unintended side effects if the task’s desired state has already been achieved. For example, if a package is already installed, Ansible won’t reinstall it.

Declarative Nature:

•  twtech describe the desired state of the system, and Ansible modules automatically determine the necessary actions to bring the system into that state.

Cross-Platform:

• Many modules are designed to work on different platforms, like Linux, Windows, macOS, or cloud providers, making Ansible highly versatile in managing a diverse infrastructure.

Simplified Syntax:

•  Modules are designed to be easy to use. Most modules follow a simple key-value argument pattern, making them user-friendly and easy to integrate into playbooks.

Standardized Output:

• Modules produce a consistent output format (success, failed, changed, skipped) that helps in troubleshooting and logging.

Sample of  Ansible Modules (scripts) in a Playbook

Here’s a simple example of an Ansible playbook using modules to install Apache on a target machine and ensure the service is running:

# installapche.yaml

---

- name: Install Apache and start the service

  hosts: twtech-webservers

  become: yes

  tasks:

    - name: Install Apache package

      ansible.builtin.yum:

        name: httpd

        state: present

    - name: Start the Apache service

      ansible.builtin.service:

        name: httpd

        state: started

        enabled: yes

# In this playbook:

• The yum module is used to install the Apache package (httpd).
• The service module is used to start the Apache service and ensure it starts on boot.

Popular Ansible Modules (scripts)

1. ansible.builtin.yum: Manages packages using the yum package manager (for RedHat-based systems).
2. ansible.builtin.apt: Manages packages using the apt package manager (for Debian-based systems).
3. ansible.builtin.service: Manages services (start, stop, restart, enable, disable).
4. ansible.builtin.file: Manages files and directories (permissions, ownership, etc.).
5. ansible.builtin.user: Manages users and groups on the system.
6. ansible.builtin.docker_container: Manages Docker containers.
7. ansible.builtin.git: Manages Git repositories (clone, pull, checkout).

Using Ansible Modules in DevOps

• Ansible modules are widely used in DevOps to automate repetitive tasks, configure infrastructure, manage cloud environments, and ensure consistency across environments. 

Some Ansible use cases in DevOps include:

Infrastructure as Code (IaC):

•  Ansible modules help define infrastructure and configurations as code, enabling version control and reproducibility.

Configuration Management:

• Modules ensure that systems are configured correctly and consistently.

Automated Deployments:

• Using modules like docker_container or k8s, you can automate application deployments in containers or Kubernetes clusters.

Provisioning Cloud Resources:

• Modules for EC2 (AWS) allow for the automatic provisioning of virtual machines and other cloud resources in the server (Host).

Managing Security

• : Security modules help automate tasks such as firewall configuration, SSH key management, and user access control.

twtech insights:

•  Ansible modules are a powerful feature of Ansible that help automate tasks, ensuring that twtech infrastructure is consistently configured and its applications are deployed efficiently in a DevOps pipeline.