Governance-as-Code, the practice of codifying governance policies, finally brings a new level of consistency, compliance, and control to cloud infrastructure. That’s especially true when you’re using Infrastructure as Code (IaC) tools like Terraform. 

But you need a strategic and well-structured approach to implement Governance-as-Code properly, and that involves four key steps: Modules, Code, Plan, and Cloud Configurations.

Before we dive in, let’s take a step back to understand why governance-as-code is so hot right now, and what tangible wins businesses are seeing from adopting it. 

Why Governance-as-Code?

Before we dive into the actual How-To and guide to implementing Governance-as-Code, let’s just talk about “the why” for a minute.  GaC enables teams to define and enforce policies through code rather than relying on manual processes, reducing human error and simplifying compliance across environments. By codifying policies, organizations can consistently apply security, compliance, and cost-optimization standards, creating a safer, more resilient infrastructure. Tools like Open Policy Agent (OPA) and AWS Config Rules can facilitate this by ensuring policies are enforced throughout the infrastructure lifecycle.

The Benefits of Governance-as-Code

The benefits of Governance-as-Code, are very similar to other practices that have derived value from applying as-code practices - we’ve spoken about this extensively - whether it’s your monitoring managed as code or GitHub-as-Code, this provides several powerful benefits, including:

  1. Reduced Misconfiguration Risks: Codifying policies enforces them consistently across environments, reducing misconfigurations.
  2. Automated Policy Enforcement: Automation frees teams from manual checks, allowing them to focus on strategic initiatives.
  3. Version-Controlled Policies: Codified policies are auditable, improving visibility and compliance reporting.
  4. Rapid Issue Remediation: In case of incidents, policies defined as code expedite response times.
  5. Scalable Governance: Governance-as-Code scales with your infrastructure, adapting to its growth and complexity.

Now, let’s explore the four crucial steps to successfully implementing Governance-as-Code to your IaC systems.

Step 1: Modules - Building Reusable Templates

Modules serve as the foundational building blocks for infrastructure, encapsulating best practices and configurations for specific resources or services. This modular approach ensures that policies and configurations are consistently applied, maintaining integrity across deployments. This is achieved through:

Immutability and Reusability:

  • By defining modules that are immutable, once created, these modules ensure consistency across deployments.
  • Use parameterized variables enables reusability without altering core logic. For example, an AWS EC2 module might include parameters for instance size or region.
  • Storing modules in a version-controlled repository (e.g., Git) will help with managing updates and maintaining an auditable history.

Compliance at the Template Level:

It is recommended to integrate compliance rules directly into the module logic. For instance:

  • Require encryption for storage resources (e.g., S3 buckets with encryption = true by default).
  • Setting secure default configurations, such as private networking or restricted access policies.
  • Using validation blocks or type constraints prevents invalid inputs (e.g., ensuring specific tags or instance types are used).

Flexibility and Customization:

  • This can be achieved by adding toggles for settings that might need to vary by deployment, such as enabling/disabling logging or encryption.
  • It is also a good practice to provide overrides where needed, while ensuring that critical policies (like security or compliance requirements) remain enforced.
  • It’s recommended to allow customization through input variables, but be sure to restrict values that would break compliance using validation or enforced defaults.

Practical Tools: Store modules in centralized registries (e.g., Terraform Registry, private Git repositories). Use static analysis tools like Checkov or TFSec to validate module integrity.

Step 2: Code - Defining Specific Infrastructure

In the Code phase, modules are invoked to create specific cloud resources. In this example, we'll demonstrate this in HashiCorp Configuration Language (HCL), but this is relevant for any configuration language for non-Hashicorp tools. This code layer adds granularity by specifying exact configurations and parameter values for each deployment.

Detail-Oriented Configurations:

  • It is recommended to write infrastructure definitions in the IaC tool’s syntax (e.g., Terraform HCL, AWS CloudFormation YAML/JSON).
  • Reference pre-built modules and pass specific variables required for the deployment in the IaC (e.g., instance type, storage capacity).

Policy Enforcement:

Applying policy checks ensures compliance with organizational standards. For example:

  • Scanning code to ensure compliance with organizational & security policies using tools like Open Policy Agent (OPA), Checkov, or KICS.
  • By enforcing tagging conventions, you can ensure resources include metadata for cost allocation, ownership, or security.

Version Control and Collaboration:

  • Pull requests (PRs) and code reviews are a good way to enforce governance policies as part of the CI/CD pipeline.
  • Incorporating automated policy checks in the CI/CD pipeline validates changes before merging.

Practical Tools: Integrate scanners like TFSec, Terrascan, or KICS into CI pipelines to validate resource definitions. Use collaborative tools like GitHub Actions or GitLab CI/CD for automated reviews.

Step 3: Plan - Bridging Code and Reality

The Plan stage is the bridge between code and the cloud environment. For example, running a Terraform plan reveals the actual changes to be applied, allowing teams to review and verify configurations against the intended policy standards.

Declarative Approach:

  • Generating the plan output (terraform plan, CloudFormation Change Sets) enables you to preview the intended changes without executing them.
  • The plan is used to identify discrepancies between desired and current states.

Runtime Validations:

  • Make sure to validate runtime dependencies, such as resolving AMI IDs or confirming network configurations, during the planning phase.
  • Don't forget to ensure that generated resources meet policy requirements, such as region-specific constraints or approved resource types.

Policy Scanning:

  • Scanning the plan output (e.g., Terraform JSON plan) is how to ensure compliance. For instance:
    • Verifying that instance types align with cost or performance policies.
    • Confirming that no unsecured resources (e.g., public buckets) will be deployed.
  • Tools like OPA or KICS provide plan-specific rules or important runtime validations respectively, against the plan output.

Practical Tools: Implement policy scanning for plan outputs in tools like Checkov, KICS, or custom OPA rules. Integrate these scans into CI/CD workflows to ensure pre-deployment compliance.

Step 4: Cloud Resource Configurations - Managing Live Resources

After deploying code to the cloud, the Cloud Configuration stage ensures ongoing compliance in the live environment. This step addresses configuration drift—changes made directly in the cloud console that bypass initial policies.

Regular Configuration Scans:

  • Cloud-native tools like AWS Config, Azure Policy, or GCP Config Connector help monitor resource configurations.
  • Scheduling regular scans of live environments makes it possible to detect drift (manual changes) or misconfigurations early and often.

Handling Drift:

  • Implementing drift detection mechanisms will enable you to compare the current state of the environment to the desired state defined in the IaC code.
  • You can automate remediation for detected drifts using tools like Terraform’s terraform apply or AWS Config Rules.

Post-Deployment Validation:

  • Make it a practice to validate properties that are only available after deployment (e.g., IP addresses, dynamically generated IDs).
  • Automating checks for these properties ensures they align with policies, such as verifying that IP ranges are within approved subnets.

Event-Driven Compliance:

  • Employing event-driven tools like AWS CloudTrail or Azure Monitor to trigger compliance checks when changes occur will ensure you don’t have any compliance breaking changes that are unchecked.
  • A good way to respond to non-compliance events is with automated remediations, such as reverting unauthorized changes.

Practical Tools: Use Cloud Custodian for event-driven governance and remediation. Combine with AWS Config Rules, Azure Policy, or GCP Policy Analyzer for continuous compliance monitoring.

Governance-as-Code for Greater DevOps Efficiencies

Implementing Governance-as-Code transforms cloud infrastructure management by embedding policy enforcement directly into the lifecycle of infrastructure provisioning and maintenance. Through 4 simple steps you can apply immediately, it’s easy to derive all of the benefits GaC provides. The strategic use of Modules helps teams to establish reusable, secure templates that act as the foundation for consistent deployments. When advancing to the Code phase, these templates are adapted to meet specific resource needs while ensuring policies are rigorously validated at the definition level. The Plan stage bridges the gap between intent and reality, offering a crucial opportunity to preview and correct potential misconfigurations before any changes are applied. Finally, Cloud Configurations ensure continuous compliance by monitoring live environments, detecting drift, and addressing deviations in real time.

This step-by-step approach doesn’t just streamline governance, it empowers organizations to proactively safeguard their cloud environments from risks, reduce operational complexity, and scale confidently. By integrating these principles into infrastructure workflows, teams can achieve a truly unified, secure, and compliant governance strategy that is easy to automate and reduce friction, while also evolving alongside their cloud systems.

To dive deeper, watch the on-demand webinar: 4 Steps To Implement Governance-As-Code To Better Control Your Cloud.Â