Ansible vs Capistrano: What are the differences?

Introduction

Ansible and Capistrano are both popular frameworks used for automation and deployment in web development. While they share some similarities, they also have key differences that set them apart.

1. Configuration Ansible operates on the principle of infrastructure as code and adopts a highly declarative approach. It uses YAML files to define the desired state of the infrastructure and handles the configuration management of various systems. Capistrano, on the other hand, is designed primarily for deploying Ruby on Rails applications and follows a more procedural approach, relying on scripts written in Ruby to handle configuration and deployment tasks.

2. Language Ansible is agentless and uses SSH to connect to target systems, allowing it to manage various types of infrastructure regardless of the underlying operating system or programming language. In contrast, Capistrano primarily targets Ruby on Rails applications and is tightly coupled with the Ruby programming language. It utilizes SSH and custom SSH multiplexing to execute commands on remote servers.

3. Community and Ecosystem Ansible boasts a larger and more diverse community compared to Capistrano. It has an extensive list of community-contributed modules and roles, making it versatile in managing different aspects of infrastructure. Capistrano, being more specific to web application deployment, has a smaller community with a focus on Ruby on Rails.

4. Ease of Use Ansible aims to have a low learning curve and emphasizes simplicity. Its configuration files are human-readable and easy to understand, making it more accessible to beginners. Capistrano, although straightforward for Ruby developers, may require a higher level of familiarity with the Ruby ecosystem and syntax.

5. Flexibility Ansible is known for its ability to manage a wide range of systems, including servers, network devices, and cloud services. It also supports complex orchestration and has integrations with popular tools and platforms. While Capistrano can handle more than Ruby on Rails applications, it is primarily focused on deploying web applications built with Ruby.

6. Deployment Strategy Capistrano follows a rolling deployment strategy, which deploys the new version of the application to one server at a time, reducing downtime and allowing for easy rollback. Ansible, however, provides flexibility in choosing the deployment strategy based on the project's requirements. It can support rolling deployments and other strategies like blue-green or canary deployments.

In summary, Ansible takes a more generic and versatile approach to infrastructure automation and configuration management, with broad language and platform support, a large community, and a focus on simplicity. Capistrano, on the other hand, is specifically tailored for Ruby on Rails application deployment, leveraging Ruby's strengths and providing a straightforward deployment process.