How can Ansible and Terraform be used together?

In the ever-evolving landscape of IT infrastructure management, tools like Ansible and Terraform have gained significant popularity. Both serve distinct purposes, with Ansible specializing in configuration management and automation, while Terraform excels in infrastructure provisioning and orchestration. Combining these powerful tools can unlock a synergistic approach to managing and deploying infrastructure. In this article, we'll explore how Ansible and Terraform can be seamlessly integrated to enhance the efficiency and flexibility of your infrastructure operations.

Why use Ansible and Terraform together?

Before diving into the integration process, it's essential to understand why using Ansible and Terraform together makes sense. Ansible excels in automating repetitive tasks and ensuring the desired state configuration of servers, making it ideal for post-provisioning configurations. On the other hand, Terraform shines during the provisioning phase, allowing infrastructure as code (IaC) to define and create resources in a declarative manner. Combining these tools enables a comprehensive infrastructure management strategy, covering both pre and post-provisioning aspects.

Setting the Stage: Installation

Before embarking on the integration journey, ensure that both Ansible and Terraform are installed on your system. Use the following commands to install Ansible and Terraform:

# Install Ansible
sudo apt-get update
sudo apt-get install ansible

# Install Terraform
curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo gpg --dearmor -o /usr/share/keyrings/hashicorp-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] https://apt.releases.hashicorp.com $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/hashicorp.list > /dev/null
sudo apt-get update && sudo apt-get install terraform

Initializing Terraform

Begin by initializing your Terraform project. Navigate to the directory containing your Terraform configuration files and run:

terraform init

This command initializes the working directory and downloads the necessary providers and modules.

Writing Terraform Configuration

Define your infrastructure in Terraform configuration files (typically with a .tf extension). Once the configuration is complete, use the following command to generate an execution plan:

terraform plan -out=tfplan

This step ensures your configurations are syntactically correct and provides a preview of the changes to be applied.

Executing Terraform

Apply the Terraform plan using the following command:

terraform apply tfplan

This command provisions the defined infrastructure.

Integrating Ansible

With the infrastructure provisioned, leverage Ansible for configuration management. Ansible can be integrated into Terraform using the local-exec provisioner.

Update your Terraform configuration to include the following provisioner block:

resource "null_resource" "ansible_provisioner" {
  provisioner "local-exec" {
    command = "ansible-playbook -i ${self.triggers.inventory_file} your_playbook.yml"
  }
}

Replace your_playbook.yml with the actual name of your Ansible playbook.

Running the Integrated Solution

Now, executing the Terraform configuration will automatically trigger the Ansible playbook, seamlessly combining infrastructure provisioning and configuration management.

terraform apply tfplan

More Examples and Advanced Usage

For more complex scenarios, consider using Ansible dynamic inventories or leveraging Terraform outputs within Ansible. Explore these advanced use cases to tailor the integration to your specific needs.