Managing Multiple Azure Environments with Terraform

Introduction

Managing cloud infrastructure across multiple environments can be complex. Terraform simplifies this process using modules and workspaces, Allows us more efficient and scalable infrastructure management in any cloud. This guide explores leveraging Terraform modules in a multi-workspace setup for Microsoft Azure. 

Benefits of Terraform Modules and Workspaces

Terraform Modules: Enhancing Reusability

Modules allow infrastructure components to be defined once and reused across different environments. This reduces redundancy and enhances maintainability.

Terraform Workspaces: Isolating Environments

Workspaces create separate states for different environments, ensuring isolation and preventing conflicts between deployments. Utilizing Terraform variables further refines environment-specific configurations.

Structuring Terraform for Multi-Environment Deployment

A well-structured Terraform directory simplifies management across environments. Below is a recommended directory structure:

Directory Layout

$ tree complete-module/
.
├── README.md
├── main.tf
├── variables.tf
├── outputs.tf
├── ...
├── modules/
│   ├── nestedA/
│   │   ├── README.md
│   │   ├── variables.tf
│   │   ├── main.tf
│   │   ├── outputs.tf
│   ├── nestedB/
│   ├── .../
├── examples/
│   ├── exampleA/
│   │   ├── main.tf
│   ├── exampleB/
│   ├── .../

Creating a Reusable Terraform Module

Defining a Virtual Network Module:

 - modules/network/main.tf

resource "azurerm_virtual_network" "network" {
  name                = var.network_name
  location            = var.location
  resource_group_name = var.resource_group_name
  address_space       = var.address_space
}

 - modules/network/variables.tf

variable "network_name" {
  type = string
}

variable "location" {
  type = string
}

variable "resource_group_name" {
  type = string
}

variable "address_space" {
  type = list(string)
}

 - modules/network/outputs.tf

output "network_id" {
  value = azurerm_virtual_network.network.id
}

Utilizing the Module in the Main Configuration

- main.tf

terraform {
  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = "4.16.0"
    }
  }

  backend "azurerm" {
    resource_group_name  = "terraform-state-rg"
    storage_account_name = "terraformstate"
    container_name       = "tfstate"
    key                  = "terraform.tfstate"
  }
}

provider "azurerm" {
  features {}
}

module "network" {
  source              = "./modules/network"
  network_name        = "my-network-${terraform.workspace}"
  location            = "East US"
  resource_group_name = "my-rg"
  address_space       = ["10.0.0.0/16"]
}

Managing Workspaces for Different Environments

Initializing and Creating Workspaces

Run the following commands to initialize Terraform and create new workspaces:

terraform init
terraform workspace new development
terraform workspace new staging
terraform workspace new production

Switch between workspaces:

terraform workspace select development

Applying Configuration to a Specific Workspace

terraform apply -var-file=environments/development.tfvars

Terraform plan output:

Terraform used the selected providers to generate the following execution plan.

Resource actions are indicated with the following symbols:

  + create

Terraform will perform the following actions:

  # module.network.azurerm_virtual_network.network will be created

  + resource "azurerm_virtual_network" "network" {

      + address_space       = ["10.0.0.0/16"]

      + id                  = (known after apply)

      + location            = "East US"

      + name                = "my-network-default"

      + resource_group_name = "my-rg"

    }

Plan: 1 to add, 0 to change, 0 to destroy.

Terraform apply output:

module.network.azurerm_virtual_network.network: Creating...

module.network.azurerm_virtual_network.network: Creation complete after 30s ...

Apply complete! Resources: 1 added, 0 changed, 0 destroyed.

Outputs:

network_id = "/.../my-rg/.../Microsoft.Network/virtualNetworks/my-network-default"

Advantages of This Approach

• Code Efficiency: Reusable modules minimize code duplication.
• Environment Segregation: Workspaces ensure different state for different environment.
• Scalability: With this approach we can easily add multiple environments as needed.

Reference links:

• https://developer.hashicorp.com/terraform/cloud-docs/workspaces
• https://developer.hashicorp.com/terraform/cloud-docs/workspaces/variables
• https://developer.hashicorp.com/terraform/tutorials/azure-get-started

Conclusion

Using Terraform modules and workspaces in Azure streamlines environment management, improves reusability, and enhances scalability. This structured approach keeps infrastructure organized and adaptable to change.

Happy Terraforming!