How Can You Achieve terraform destroy like Functionality with Ansible ?

[rixhieloomis]

How can you achieve terraform destroy like functionality with Ansible?

[rixhieloomis]

When discussing how to destroy infrastructure with Ansible in a way similar to Terraform’s terraform destroy command, it's important to understand the key differences in how these tools handle infrastructure.

Terraform vs. Ansible for Destroying Infrastructure

Terraform

• Terraform is designed for full infrastructure lifecycle management, including provisioning, updating, and destruction.
• The terraform destroy command uses the same infrastructure code to tear down resources, leveraging a state file to track and understand the dependencies between resources.
• Terraform automatically handles the order in which resources should be destroyed, preventing dependency issues (e.g., not trying to delete a VPC before all its associated instances have been removed).

Ansible

• Ansible is primarily focused on configuration management rather than managing infrastructure lifecycle. While you can provision resources using Ansible, it doesn’t natively include a command like terraform destroy.
• To replicate Terraform’s destruction capabilities, you would need to write a separate de-provisioning playbook in Ansible that manually reverses the provisioning actions.

Achieving terraform destroy with Ansible

To achieve infrastructure destruction in Ansible, follow these steps:

1. Reverse the Order of Playbooks

In Terraform, the system automatically tracks the dependencies between resources and manages their destruction in the correct order. In Ansible, you’ll need to manually define the order in which resources are destroyed. For example, if you provision resources in this order:

• VPC
• Subnet
• Internet Gateway
• EC2 Instances

When tearing them down, you’ll need to reverse the order:

• EC2 Instances
• Internet Gateway
• Subnet
• VPC

2. Use Modules with state: absent

Ansible modules generally support a state parameter. To destroy resources, you would use state: absent for each resource type. For example, to terminate an EC2 instance:

- name: Terminate EC2 instance
  amazon.aws.ec2_instance:
    state: absent
    filters:
      instance-state-name: running

You would similarly define tasks for other resources, ensuring they are removed in the correct sequence.

3. Manual Dependency Management

Unlike Terraform, Ansible does not track dependencies between resources. You need to make sure the playbooks are designed to remove resources in a logical order, preventing dependency issues (such as trying to delete a VPC while instances still exist within it).

4. Update Your Inventory

Ensure that your Ansible inventory is up to date with the resources you want to destroy. Since Ansible does not maintain a state file, it's up to you to track the resources and include them in the playbook.

Summary
While Terraform is built to manage the full infrastructure lifecycle and handles destruction automatically with the terraform destroy command, Ansible can achieve the same result, albeit with more manual effort. You’ll need to write separate playbooks to reverse the creation process and ensure the correct sequence for destroying resources.

Terraform’s state management and dependency tracking make it much easier and safer to handle infrastructure destruction, while Ansible requires more careful planning and manual control to avoid issues.