Terraform Azure

What is IaC?

Infrastructure as Code (IaC) uses files instead of manual interfaces, with tools like Terraform employing the HashiCorp Configuration Language (HCL) to automate resource creation. It involves declarative provisioning and post-provisioning configuration adjustments.

What is Terraform?

HashiCorp Terraform is a free tool for managing cloud infrastructure through configuration files. It supports various environments, utilizing "Terraform providers."

Benefits 1. Unified IaC Tool: Terraform Azure providers simplify resource configurations and efficiently automate Azure DevOps within the Cloud Adoption Framework for Enterprise-scale.

2. Automated Infrastructure Management: Terraform Azure's templates ensure reliable and predictable Azure resource creation, minimizing errors, enabling reuse, and reducing costs.

3. Preview Infrastructure Changes: Terraform Azure's CLI previews changes, enhancing teamwork, detecting unintended modifications early, and providing a clearer grasp of infrastructure alterations.

How does it Work?

Terraform Azure Workflow in Four Steps:

1. Define Resources:

• Specify cloud resources according to enviroment
• Create resource list

2. Create Configuration Files: Generate configuration files based on the resource list, acting as infrastructure blueprints.

3. Initialize: Execute terraform init to set up Terraform in the project directory, configuring it for your files.

4. Plan & Apply: Use terraform plan to review changes, confirm expectations, and then employ terraform apply to create resources. This process maintains a state file, enabling Terraform to track the current environment state.

Typical terraform azure configuration file:

How to Install Terraform?

  Steps to install and set up the Terraform CLI for local usage:

1. Terraform Executable Zip File: Download the Terraform azure executable by acquiring the zip package from the official HashiCorp website.

3. Package Extraction: Extract package

5. Move terraform.exe to C:\Windows for universal PowerShell or CMD access.

6. Alternative Path Configuration: To place the file anywhere, update 'Environment Variables' with the Terraform executable path.

Verify correct installation:

Terraform Commands

After installing Terraform azure CLI, restart your terminal if you change the path or executable location to ensure correct configuration. Confirm recognition by running the help command to validate the installation.

Terraform Help

After validating the installation, run the command below to access help information for various Terraform azure commands.

Review the execution plan to understand Terraform Azure's actions.

Terraform Init

"terraform init" ensures you have all project components and plugins before deploying infrastructure.

Use "terraform plan" to review and re-run for module or backend config changes.

Terraform Plan

After "terraform init," your project is ready for testing and deployment. "terraform plan" generates an execution plan with symbols indicating infrastructure changes for "terraform apply."

Let's take a look at the output of the terraform plan.

Use "terraform plan -out" to export the plan to a file for later infrastructure changes.

In CI/CD with Terraform azure, store the Plan file (tfplan) separately for distinct planning and applying stages.

Terraform Apply

After the execution plan, run 'terraform apply' command to do the planning and deployment. Respond yes to the prompt to confirm the changes.

Terraform Azure generates an execution plan by comparing the desired configuration state to the current state, stored either locally in terraform.tfstate or remotely in a state backend.

Terraform Destroy

Terraform destroy functions as the opposite of terraform apply, allowing you to terminate resources managed by your project. Execute the destruction plan by typing "yes"

The '-' prefix in Terraform Azure output means the instance will be deleted. Terraform, like with apply, shows the proposed action and waits for approval. It plans the destruction sequence to account for resource dependencies in complex scenarios.

Terraform State

Terraform manages configurations with plans, applies, and destructions. Securely store resulting files in remote storage for collaboration, and check the current state using terraform show.

Terraform providers for Azure

There are several Terraform azure providers that enable the management of Azure infrastructure: