Why and how to adopt Infrastructure as Code (IaC)

Platform, engineering and IT teams constantly provision new databases, configure servers, set up networking, provision storage, etc. to create infrastructure for applications to run. When done manually, the process is slow, prone to errors, tedious and leads to inconsistency and configuration drift across systems. Absence of automation also creates obstacles in adopting rapid iteration and efficient collaboration.

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Infrastructure as code (IaC) is the ability to provision and configure computing infrastructure using code instead of manual processes. IaC treats infrastructure as software defined by declarative code. This code specifies the desired state of your infrastructure, freeing you from manual configuration and paving the way for automation, repeatability, and scalability. It is a blueprint for your cloud environment, ensuring consistency and reducing the risk of human error, just like building from a detailed architectural plan. IaC transforms ephemeral cloud resources into code, stored and version-controlled alongside application code.

• Consistency and Standardization: IaC ensures that every instance of the infrastructure is provisioned in exactly the same way, offering a consistent and standardized environment for development, testing, and production.
• Speed and Efficiency in Deployment: IaC automates the provisioning process, dramatically speeding up deployments and enabling quick iterations, which is crucial for agile development and continuous integration/continuous deployment (CI/CD) practices.
• Scalability and Flexibility: With IaC, scaling up or down can be as simple as updating a few lines of code. This flexibility allows teams to easily adjust their infrastructure based on current needs, without manual intervention.
• Cost Optimization: IaC allows for precise control over resource allocation, ensuring that you only use what is necessary and can adjust quickly to changes, thus optimizing costs.
• Disaster Recovery: With IaC, the entire infrastructure is defined in code. This means that it can be quickly recreated or restored, ensuring a faster recovery from failures.
• Documentation and Visibility: In IaC, the code itself serves as documentation, clearly defining the infrastructure setup. This increases visibility and understanding among team members.
• Security and Compliance: IaC allows for incorporating security and compliance configurations directly into the code. This ensures that every instance of the infrastructure is compliant and reduces the risk of security gaps.
• Version Control and Change Management: Like any code, infrastructure as code can be version-controlled using tools like Git. This allows for tracking changes, reverting to previous versions if necessary, and understanding the evolution of the infrastructure over time.
• Developer Satisfaction: Deploying code is a repetitive and tedious task. IaC gives the power to create the infrastructure through code, which is something that developers love.

IaC Workflow

There are many IaC tools available - Terraform, Pulumi, Ansible, Puppet, etc. Understanding the types of IaC and their appropriate use cases is crucial for effectively managing infrastructure in cloud and on-premises environments. Each type has its strengths and is suited for different scenarios, depending on the complexity, scale, and specific requirements of the infrastructure it manages.

1. Declarative (Functional) IaC: In declarative IaC, you specify the desired state of your infrastructure, but not the steps to achieve it. The IaC tool is responsible for determining how to create that state.

   • Example: Defining a desired state, like “I want three server instances running,” and the tool figures out how to achieve that state.
   • Tools: Terraform, AWS CloudFormation, Azure Resource Manager.

2. Imperative (Procedural) IaC: With imperative IaC, you define the specific commands or steps needed to create the desired infrastructure. It's more about the process (how) rather than the outcome (what).

   • Example: Writing a script that says “create a new server instance, then configure it this way.”
   • Tools: Ansible, Chef, Puppet, SaltStack, Bash scripts.

3. Orchestration vs. Configuration Management

   • Orchestration IaC: This type focuses on coordinating and managing the lifecycle of complex environments and systems (like multi-tier applications). It's about how different parts of the infrastructure interact and work together.
   • Configuration Management IaC: This type is more focused on maintaining and managing the state of individual systems (like ensuring a specific software version is installed on all servers).
   • Tools: Kubernetes and Docker Swarm are often used for orchestration, while Puppet, Chef, and Ansible are popular for configuration management.

4. Mutable vs. Immutable Infrastructure

   • Mutable Infrastructure: In mutable infrastructure, updates and changes are made in-place to existing servers. This can lead to configuration drift over time.
   • Immutable Infrastructure: Immutable infrastructure treats servers and other components as replaceable. Instead of updating, you replace the entire server or container with a new instance whenever changes are needed.
   • Tools: Docker and other containerization tools support the immutable infrastructure approach, while traditional configuration management tools often manage mutable infrastructure.

5. Domain-Specific Language (DSL) vs. General-Purpose Language

   • DSL-Based IaC: These are specialized languages designed specifically for describing and managing infrastructure (e.g., HashiCorp Configuration Language used by Terraform).
   • General-Purpose Language: Using common programming languages (like Python, Ruby, or JavaScript) to define infrastructure. E.g. Pulumi

The below table compares some of the IaC tools based on the above categories and capabilities.

Next Steps

Implementing IaC involves a structured approach to ensure a smooth transition and effective utilization. Here's a step-by-step guide to get started:

1. Assessment and Planning: Assess the existing infrastructure setup. Identify what is manually managed and what can be automated. Involve key stakeholders, including IT operations, developers, and management, to understand their needs and concerns. Define what you want to achieve with IaC, be it speed, scalability, cost savings, or consistency.

2. Choose the Right Tools: Refer to the section and table above and based on your specific needs, choose tools that are compatible with your existing technology stack and infrastructure.

3. Start Small: Start with a small, low-risk project to implement IaC.

4. Implement Version Control: Store your IaC configurations in a version control system like Git. This allows tracking changes, peer reviews, and maintaining a history of your infrastructure changes.

5. Test and Iterate: Test your IaC implementations in isolated environments. Ensure everything works as expected and complies with your security and compliance policies. Obtain feedback from the team and stakeholders involved in the pilot project. Make improvements based on the feedback and lessons learned.

6. Scale and Expand: Once comfortable with the pilot project, gradually start applying IaC to other projects or services. Continuously refine and improve your IaC practices as you scale.

7. Integrate into CI/CD Pipelines: Integrate IaC into your CI/CD pipelines for automated testing and deployment. Implement monitoring and logging to continuously track the performance and health of your infrastructure.

By treating infrastructure as if it were software code, IaC allows for automated, consistent, and repeatable deployment processes, greatly reducing human errors and operational overhead. The ability to version control infrastructure changes brings an unprecedented level of transparency and traceability, while also facilitating easier rollbacks and enhanced security. IaC not only helps in streamlining operations, it lays down a foundation for a more resilient, efficient, and future-proof IT ecosystem.

Let me know your thoughts or insights from your IaC journey.