What Is Ansible?
Bron: artikel integraal overgenomen van medium
Origineel auteur: Mohammed
Introduction
Ansible is an open-source IT automation tool that simplifies and automates various manual IT processes, including provisioning, configuration management, application deployment, and orchestration. It is designed to be minimal, consistent, secure, and highly reliable, with an extremely low learning curve for administrators, developers, and IT managers.
Ansible is primarily intended for IT professionals who use it for tasks such as application deployment, updates on workstations and servers, cloud provisioning, configuration management, and intra-service orchestration. & It enables cross-platform automation and orchestration at scale.
It is created by contributions from an active open-source community. Ansible is designed to be simple, powerful, and agentless, which means it does not require any software or agents to be installed on the managed nodes.
Ansible uses a declarative language called YAML to define automation tasks, which makes it easy to read and understand.
Prequisites
The concepts and demos used in this blogpost require Ansible and AWX setup. If you are looking to quickly setup and explore AWX , Techlatest.net provides out of the box setup for latest AWX version on AWS, Azure and GCP. Please follow below links for the step by step guide to setup AWX on your choice of cloud platform.
Ansible Playbooks
An Ansible Playbook is a blueprint of automation tasks that are executed with limited manual effort across an inventory of IT solutions. Playbooks tell Ansible what to do and how to do it. They are written in YAML and can be used to automate a wide range of tasks, from simple configuration management to complex application deployments. Playbooks can be executed on a single node or multiple nodes at the same time, making it easy to manage infrastructure at scale. Basic Principles Underlying the Ansible Design
The basic principles underlying the Ansible design are:
1 Desired state engine: Ansible is a desired state engine by design. It focuses on giving you a description of the state you want rather than on performing specific tasks. 2 Idempotent: Ansible’s design is based on the idempotent principle. Everything is accomplished only when required and does not have any side effects. 3 Agentless architecture: Ansible uses an agentless architecture, which means it does not require any software or agents to be installed on the managed nodes. This reduces maintenance overhead by avoiding the installation of additional software across IT infrastructure. 4 Simplicity: Ansible is designed to be simple, powerful, and easy to learn and use. It uses straightforward YAML syntax for code that reads like documentation. 5 Scalability and flexibility: Ansible is designed to be scalable and flexible. It supports a large range of operating systems, cloud platforms, and network devices. 6 Modularity: Ansible uses modules to break down complex tasks into smaller, more manageable pieces. 7 Declarative: Ansible is not meant to be used for programming, so avoid writing code in your plays and roles. Treat your Ansible content like code. 8 Consistency: Use prefixes and human meaningful names with variables to make them easy to understand and manage. Create a style guide for developers and enforce the style. 9 Testing: Test your playbooks thoroughly before deploying them to production. 10 Documentation: Document your playbooks and keep them up to date.
By following these principles, Ansible can help users automate repetitive tasks, manage infrastructure, and deploy applications at scale.
How Ansible Works
Overview of how Ansible works in a series of key points:
1 Control Node: Ansible is operated from a control node, where you write and execute your Ansible playbooks and commands. 2 SSH or WinRM: Ansible communicates with the managed nodes using SSH (for Unix-based systems) or WinRM (for Windows systems). 3 Inventory: Ansible uses an inventory file that lists the IP addresses or hostnames of the managed nodes. This inventory can be static (defined in a file) or dynamic (generated programmatically). 4 Playbooks: Playbooks are written in YAML format and contain a set of tasks to be executed on the managed nodes. Playbooks define the desired state of the system. 5 Modules: Tasks within playbooks are executed using Ansible modules. Modules are small, reusable pieces of code that carry out specific actions on managed nodes, such as installing packages, managing files, or configuring services. 6 Idempotency: Ansible ensures that tasks are idempotent, meaning they can be run multiple times without changing the system’s state if it’s already in the desired state. 7 Task Execution: Ansible connects to managed nodes using SSH or WinRM and executes tasks in the order defined in the playbook. It reports the status of each task. 8 Parallel Execution: Ansible can execute tasks in parallel on multiple managed nodes, which helps save time when managing a large infrastructure. 9 Gathering Facts: Ansible can gather information about the managed nodes (facts) using built-in modules. These facts can be used in playbooks for conditional tasks. 10 Handlers: Ansible includes handlers that are tasks triggered by other tasks. Handlers are typically used for restarting services or taking other actions only when necessary. 11 Role-Based Organization: Ansible encourages the organization of playbooks into roles, making it easier to reuse and share collections of tasks and variables. 12 Variable Management: Variables can be defined in playbooks, inventories, or role-specific files to make playbooks flexible and adaptable to different environments. 13 Error Handling: Ansible provides error handling capabilities, allowing you to define actions to take in case of task failures. 14 Ad-Hoc Commands: In addition to playbooks, Ansible allows you to run ad-hoc commands for quick, one-time tasks on managed nodes. 15 Extensibility: Ansible can be extended by creating custom modules, plugins, and roles to address specific automation requirements. 16 Reporting and Logging: Ansible generates detailed logs and reports, providing insights into the status and outcome of tasks. 17 Version Control Integration: Playbooks can be stored in version control systems like Git, allowing for versioning, collaboration, and history tracking.
Understanding the Components of Ansible
The components of Ansible are:
1 Inventory file(s): Contains a list of hosts that Ansible interacts with. It can be static or dynamic and is specified when running an Ansible playbook. 2 Group vars and Host vars: Pertains to the groups and hosts specified in the inventory file(s). Variables can be assigned to groups or individual hosts. 3 Playbooks: A blueprint of automation tasks that are executed with limited manual effort across an inventory of IT solutions. Playbooks tell Ansible what to do and how to do it. They are written in YAML and can be used to automate a wide range of tasks. 4 Roles: A way to break down complex tasks into smaller, more manageable pieces. Roles contain lists of tasks that perform the work you’ve configured them to do. 5 Tasks: The individual steps that Ansible executes. Tasks are defined in playbooks and can be used to install packages, configure services, and more. 6 Modules: Ansible uses modules to perform specific tasks. Modules can be used to manage files, install packages, and configure services, among other things. 7 Facts: The way of getting data from systems. Facts can be used in playbook variables and can be disabled if not required. 8 Templates: The definition and set of parameters for running an Ansible job. Job templates are useful to execute the same job many times. 9 Configuration files: Ansible uses a configuration file to specify settings such as the location of the inventory file and the SSH user to use when connecting to managed nodes. 10 SSH: Ansible uses SSH to connect to managed nodes and run tasks.
By understanding these components, users can effectively use Ansible to automate repetitive tasks, manage infrastructure, and deploy applications at scale.
Use Cases of Ansible
Ansible is a versatile tool that can be used for a variety of purposes. Here are some common use cases of Ansible:
1 Configuration management: Ansible can be used to manage system configurations across multiple servers. It can install software packages, configure networking settings, and update system configurations. 2 Application deployment: Ansible can be used to deploy applications across multiple servers. It can automate the deployment process and ensure that everything is working correctly before rolling out an actual production environment. 3 Provisioning infrastructure: Ansible can be used to provision the underlying infrastructure of your environment, virtualized hosts and hypervisors, network devices, and bare-metal servers. 4 Continuous delivery: Ansible can be used to continuously deliver complex software. It can perform zero-downtime rolling updates and ensure that the system remains in the desired state. 5 Testing: Ansible can be used to test the deployment process and ensure that everything is working correctly before rolling out an actual production environment. 6 Security: Ansible can be used to automate security tasks such as patch management, vulnerability scanning, and compliance auditing.
By using Ansible, users can automate repetitive tasks, manage infrastructure, and deploy applications at scale. Ansible is a powerful, secure, and flexible open-source IT automation tool that can manage a wide variety of IT systems such as servers, desktops, networking devices, and databases.
Conclusion
In conclusion, Ansible is a versatile and powerful open-source automation tool designed to simplify IT processes. Its agentless, declarative, and idempotent nature, along with its easy-to-learn YAML syntax, make it an ideal choice for configuration management, application deployment, provisioning, and more. With a clear understanding of its components and principles, users can harness Ansible’s capabilities to automate tasks, manage infrastructure, and deploy applications efficiently at scale.