AZ-400: Designing and Implementing Microsoft DevOps Solutions

Design and Implement Infrastructure as Code IaC

Define an IaC strategy

In this lesson, we’ll explore how to build a robust Infrastructure as Code (IaC) strategy for Azure. You’ll learn the fundamentals of IaC, its benefits, and how it integrates into DevOps workflows to automate, version, and scale your cloud infrastructure.

What Is Infrastructure as Code?

Infrastructure as Code (IaC) refers to managing and provisioning computing resources through machine-readable definition files rather than manual processes. Treating infrastructure configurations as code enables you to:

  • Deploy resources consistently
  • Version-control all changes
  • Scale environments reliably

The image is an introduction slide for "Infrastructure as Code (IaC)" with a cloud icon and a brief description of IaC as a DevOps practice involving infrastructure management through machine-readable files.

Key Benefits of IaC

BenefitDescription
ReliabilityAutomates provisioning to reduce human error
RepeatabilityEnsures identical environment setups across deployments
ScalabilitySimplifies management of large, distributed infrastructures

The image is an introduction to "Infrastructure as Code (IaC)" highlighting three key concepts: Reliability, Repeatability, and Scalability, each represented by a numbered card.

How IaC Works in Azure

A streamlined Azure IaC workflow typically follows these steps:

  1. Write infrastructure definitions (ARM templates, Terraform .tf files, etc.).
  2. Store all scripts in a source code repository.
  3. Validate and plan changes using an IaC engine (Azure Resource Manager, Terraform, Ansible).
  4. Integrate definitions into a CI/CD pipeline for automated testing.
  5. Apply or update Azure resources automatically.

Source Control for IaC

Version control underpins every high-performing IaC pipeline by providing:

  • Change tracking: Maintain a history of every modification.
  • Collaboration: Multiple engineers can safely work on the same infrastructure code.

Warning

Always enforce pull request reviews and branch protection rules. Unreviewed infrastructure changes can lead to unexpected outages.

Best practices:

  • Adopt a branching strategy (feature, release, hotfix).
  • Write clear, descriptive commit messages.
  • Use pull requests for peer review and policy enforcement.
PlatformUse CaseIntegration
GitHubPublic and private repositories with community CIGitHub Actions
Azure ReposEnterprise-grade Git with built-in Azure securityAzure Pipelines

The image outlines three aspects of source control in Infrastructure as Code (IaC): branching strategies, commit guidelines, and pull requests for code reviews.

Automated Testing for IaC

Incorporating automated tests into your IaC workflow catches issues early and enforces compliance. Common test types include:

Test TypePurposeExample Tool
Unit TestsValidate individual modules or scriptsPester (PowerShell)
Integration TestsVerify interactions among multiple componentsTerratest (Go)
Security TestsEnforce security and policy complianceInSpec, Checkov

The image illustrates the automation of testing for Infrastructure as Code (IaC) with three steps: unit tests for individual modules, integration tests for combined components, and security tests for compliance checks.

Automating IaC Deployments

Continuous deployment for IaC ensures that every infrastructure change is automatically tested, validated, and applied in a consistent manner.

The image is a slide titled "Automating Deployment for IaC," explaining that continuous deployment for Infrastructure as Code involves automating the deployment process to ensure reliable and repeatable infrastructure changes.

Principles of Continuous Deployment

  1. Automation: Eliminate manual steps to reduce errors.
  2. Version Control: Version every change to your definitions.
  3. Continuous Testing: Catch defects as early as possible.
  4. Continuous Monitoring: Track health and performance of resources.
  5. Idempotency: Ensure repeated runs yield identical states.
  6. Rapid Feedback: Integrate team feedback loops for ongoing improvements.

Note

Idempotent scripts guarantee that running the same definition multiple times won’t produce drift. This is critical for repeatable and reliable deployments.

Azure Pipelines for IaC

Azure Pipelines provides a cloud-hosted CI/CD service for both application and infrastructure code. With Azure Pipelines, you can:

  • Build and validate IaC scripts (ARM, Terraform, Bicep).
  • Run automated tests to enforce quality and compliance.
  • Deploy resource changes safely and at scale in Azure.

The image is an infographic about automating deployment for Infrastructure as Code (IaC) using Azure Pipelines, highlighting three steps: building, testing, and deploying applications and infrastructure.

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