Unlock the Power of Terraform: A Real-World Guide

Why Terraform?

When it comes to managing cloud resources, Terraform stands out from the crowd. Unlike tools like Ansible, which focus on provisioning software and machines, Terraform takes a code-first approach to creating infrastructure resources. This means you can define your infrastructure with code, rather than relying on endless YAML files of configuration. Plus, Terraform’s reusable parameterized modules make it a game-changer.

The Importance of Remote State Storage

One crucial aspect of Terraform that’s often overlooked is state storage. Terraform must store state about your managed infrastructure and configuration, which is used to map real-world resources to your configuration, keep track of metadata, and improve performance for large infrastructures. By default, the Terraform state is stored on the local file system, but this is a major security risk. Instead, store your Terraform state remotely, such as in Azure Blob storage.

Setting Up Remote State Storage in Azure

To set up remote state storage in Azure, you’ll need to create the necessary resources, including an Azure resource group, storage account, Blob storage container, key vault store, and service principal. You can use the Azure CLI tools to create these resources.

az group create --name my-resource-group --location westus
az storage account create --name mystorageaccount --resource-group my-resource-group --location westus --sku Standard_LRS
az storage container create --name mycontainer --account-name mystorageaccount
az keyvault create --name mykeyvault --resource-group my-resource-group --location westus
az ad sp create-for-rbac --name myserviceprincipal --role Contributor --scopes /subscriptions/{subscription-id}/resourceGroups/my-resource-group

Once you’ve set up your remote state storage, you can configure Terraform to store its state there.

Terraform Workspaces

In a real-world scenario, you’ll likely have multiple environments, such as dev, staging, and production. Terraform’s concept of workspaces helps you manage these environments. By default, Terraform starts with a default workspace, but you can create separate workspaces for each environment. Terraform stores the state for each workspace in a separate state file in the remote storage.

workspace {
  name = "dev"
}

workspace {
  name = "staging"
}

workspace {
  name = "production"
}

Running Terraform through Docker

Running Terraform through Docker offers numerous benefits, including:

• Predictable OS
• Encapsulated requirements
• Build once, run everywhere
• Versioned images
• Consistent deployment experience

You can create a Dockerfile that installs both Terraform and the Azure CLI tools, and then build and run the image with the necessary environment variables.

FROM ubuntu:latest

RUN apt-get update && apt-get install -y terraform azure-cli

ENV TF_PLUGIN_CACHE_DIR=/root/.terraform.d/plugin-cache
ENV TF_DATA_DIR=/root/.terraform.d

WORKDIR /root

CMD ["terraform", "init"]
CMD ["terraform", "apply"]

Terraform Modules

Terraform modules are a powerful feature that allows you to create reusable code blocks with input and output variables. This makes it easy to create modular, scalable infrastructure code.

module "my_module" {
  source = file("./modules/my_module")

  input_var = "input_value"
}

output "output_var" {
  value = module.my_module.output_value
}

By using modules with input and output variables, you can create a robust, scalable infrastructure that meets your needs.