Infrastructure as Code (IAC): Benefits, Methodologies, and Best Practices

Infrastructure as code is the practice of using software techniques to manage the infrastructure that supports the systems we build. This includes things like operating systems, programming languages, messaging systems, and databases. By automating the provisioning and updating of our infrastructure, we can achieve repeatability and reliability, and avoid the common problem of “it worked on my machine” due to differences in environments.

There are three main methodologies for describing infrastructure as code: ad hoc, configuration synchronization, and version controlled. Ad hoc involves manually configuring and administering each server, which is prone to errors and lack of repeatability. This is the most common approach and is often used in bureaucratic organizations that try to implement paper procedures to make the process more repeatable. However, this can still lead to configuration errors, as each server is unique and manually configured. This is known as the snowflake or work of art pattern, and can be a major liability as it does not allow for proper configuration management.

Configuration synchronization involves storing a central model of the configuration and reproducing it on a timed basis whenever it’s needed. This allows for a declarative definition of servers and infrastructure, and makes it easier to scale changes. The central model can be version managed, so we can replay it and make incremental modifications. This method works best when the service cannot be manually accessed, as manual access can lead to configuration drift.

Version controlled involves storing the configuration in version control and applying changes through code. This allows for easy tracking and rollback of changes, and can be integrated with a continuous delivery pipeline. This approach allows for the greatest control and visibility into the configuration of our infrastructure.

To achieve infrastructure as code, there are five underlying principles to follow: everything is code, version control everything, keep environment-specific information separate, automate provisioning and management, and test everything.

The first principle, everything is code, means that all aspects of our infrastructure should be treated as code and stored in version control. This includes configuration files, scripts, and documentation.

The second principle, version control everything, means that we should store all of our infrastructure code in a version control system, such as Git. This allows us to track changes, revert to previous versions, and collaborate with others.

The third principle, keep environment-specific information separate, means that we should store environment-specific information, such as passwords and IP addresses, in separate configuration files or variables. This allows us to easily switch between environments, such as development, staging, and production.

The fourth principle, automate provisioning and management, means that we should use tools and scripts to automate the provisioning and management of our infrastructure. This can include things like configuration management tools, cloud provisioning tools, and container orchestration tools.

The fifth principle, test everything, means that we should test our infrastructure code and changes just like we would test our application code. This includes things like unit tests, integration tests, and acceptance tests.

These seven practices that can help organisations adopt infrastructure as code:

1. Version control your infrastructure: Store all of your infrastructure code in a version control system, such as Git.

2. Automate the provisioning and management of infrastructure: Use tools and scripts to automate the provisioning and management of your infrastructure.

3. Keep environment-specific information separate: Store environment-specific information, such as passwords and IP addresses, in separate configuration files or variables.

4. Test everything: Test your infrastructure code and changes just like you would test your application code, including unit tests, integration tests, and acceptance tests.

5. Establish a strong review process: Set up a review process for infrastructure code changes to ensure quality and consistency.

6. Use continuous integration and delivery for infrastructure: Integrate infrastructure code changes into a continuous integration and delivery pipeline to automatically build, test, and deploy changes.

7. Enable self-service: Use infrastructure as code to enable self-service for developers and other teams, allowing them to easily provision and manage their own infrastructure.