Art of Cloud Automation


Businesses often face challenges with access management as companies grow and environments become complex.

Access-as-code is a methodology where access control mechanisms are based on code, meaning that the rules governing who or what can do are codifiable, testable, versionable, and auditable. null_resource can be employed in an access-as-code approach in the following way:

  1. Define YAML manifest: Write the rules that dictate access to various resources in a YAML file. This file will act as the single source of truth for the permissions in your system. You could have rules that map teams/users to permissions, environment access, etc.
  2. Using null_resource to apply changes: In your Terraform configuration, you can use the null_resource to monitor changes in the YAML file. Using provisioners like local-exec, you can write a script that parses the YAML file and applies the changes to your systems. The triggers block inside null_resource can be used to watch the changes in the YAML file.
  3. Applying state changes: The state of the null_resource will change whenever the YAML file is modified, triggering Terraform provider actions and scripts, which will change the state of your resources to align with the rules defined in your YAML file.
  4. Remote State: Note that null_resource doesn't inherently store outputs. To capture and store the output of a script or command after it's been run with a null_resource, you would do that via a data resource or an output block in conjunction with the remote state. But based directly on null_resource alone, no values are stored in the Terraform state.
  5. Testing and auditing: Because your access rules are in code form, it is easier to implement testing and auditing on the rules themselves, and enforcements can be validated through the Terraform plan before any changes are applied.

Using a YAML manifest to define business/logical rules, organizations can streamline access control, significantly reducing the possibility of human error while ensuring that access permissions are current, accurate, and secure. It also enables versioning control of access rules, which adds an extra layer of security by allowing audits and maintaining a history of changes.

This approach supports adaptability and scalability, as updating or modifying access rules is as simple as modifying a YAML file.

Coupled with the automation power of Terraform, it makes managing and monitoring changes to these access rules more efficient. This enhances operational efficiency and contributes to business resilience, data confidentiality, and compliance.