What's Inside

With policy as code (PaC), policy documents such as security, compliance, or operations documents are translated into machine-readable instructions. This allows organizations to define, manage, update, and uniformly apply policies by leveraging code and automation. In that context, software development benefits—such as version control, automated testing, and automated deployment—become applicable to prevent misconfigurations and mitigate the risk of security vulnerabilities. 

In this article, we explore how policy as code integrates with other “as-code” methodologies, highlight best practices for its implementation, and provide a practical example to demonstrate its effectiveness in real-world environments.

Summary of Key Policy-as-Code Best Practices

Understand the Nuances Behind “As-Code” Approaches

The “as-code” methodology represents a paradigm in IT operations where infrastructures, configurations, and rules are defined, automated, and enforced using a high-level descriptive language to ensure repeatability, consistency, and efficiency. This approach is mostly beneficial in highly dynamic and complex systems, such as cloud and DevOps environments, where manual processes are impractical.

When discussing as-code methods, four main approaches are generally encountered:

• Infrastructure as code involves using code to define, configure, manage, and provision IT infrastructure such as servers, cloud instances, operating systems, networks, and storage. It represents an integral part of an efficient DevOps implementation, enabling the deployment of an application's infrastructure at scale.

• Security as code aims to embed security within the software development lifecycle (SDLC) to perform security checks and enforce strict security standards such as network segmentation, data encryption, or least privilege access.

• Compliance as code leverages code to define and enforce regulatory requirements by automating compliance checks against industry standards such as HIPAA, NIST, or GDPR. Like infrastructure as code, it can be implemented within DevOps workflows and pipelines.

• Policy as code refers to the practice of defining and enforcing any type of organizational policy through code, be it compliance, security, or operational policies. As such, it can sometimes relate to previously introduced “as code” methodologies. For instance, while a legal framework guides compliance as code and requires an audit to ensure adherence to industry standards, PaC is not subject to the same constraints. Still, it can often be used to maintain compliance.

Some examples of policy rules that can be implemented through policy as code are preventing the creation of overly permissive roles, defining a minimum length for systems or account passwords, or selecting the type of encryption algorithms and key length for the protection of sensitive data.

Clarify Your Requirements and Define Your Policies

Policies are a critical part of any organization, providing a roadmap for day-to-day operations and helping businesses implement their strategies and achieve their objectives. They guide decision-making, streamline internal processes, and ensure compliance with laws and regulations.

Before implementing any type of policy-as-code process within your organization, it is essential to thoroughly assess your current situation to determine the policies needed. This initial analysis should identify your business objectives, the industry standards applicable to your company, your organization's current strengths and weaknesses, and any existing gaps in your processes. By establishing this comprehensive overview, you will be more efficient at defining the objectives and scope of the policies that must be implemented. 

At a minimum, a written policy document should include the following components:

• Purpose: The reason for having this policy

• Scope: The elements (resources, people, infrastructures) to which the policy applies

• Implementation responsibilities: The individuals responsible for implementing the policy 

• Approval responsibilities: The individuals responsible for reviewing and approving the policy

• Content or description of the policy

• Consequences of not adhering to the policy

Depending on your organization, you might have to implement various policies, such as a policy on data protection to preserve sensitive data, another on the use of company equipment to ensure proper assets handling, one on health and safety to maintain a safe working environment, another on information security to protect digital assets, or perhaps a code of conduct to share expected employee behaviors.

Research and Select the Relevant Resources

After identifying policies aligning with your organizational goals and regulatory requirements, the next step is translating your written documents to their code counterparts whenever possible. This involves evaluating your technical stack to select the right combination of PaC tools suitable to your needs. This decision should be based on the policies to deploy, employee skills, the existence of community support for the tools selected, compatibility with your existing technologies, and the practicality of the tools within your operational environment.

Various PaC tools are available on the market. Some popular tools are:

• Drata: A platform with compliance-as-code capabilities to address compliance and security gaps related to standards such as SOC 2, HIPAA, or PCI-DSS

• Checkov: An analysis tool for scanning infrastructure-as-code files for misconfiguration

• Terraform: A framework for policy as code in infrastructure provisioning and management

• AWS Config Rules: An AWS service to assess, audit, and evaluate the configuration of AWS resources and environments

• HashiCorp's Sentinel: A framework for policy-as-code management

• Open Policy Agent (OPA): An open-source policy engine enabling policy-based control for cloud-native environments

The figure below illustrates the decision-making process for Open Policy Agent. In that context, policy as code relies on three main components to operate:

• The policy is a text file written in a high-level declarative language (such as Rego, Cedar, or YAML) containing the necessary code implementing the policy.

• The data is a database containing information about an application, a service, or the environment.

• The query is responsible for triggering the decision-making process based on the data available and the policy uploaded to the policy engine.

OPA outputs a policy decision by analyzing the query input against policies and data stored in the system.

Test and Monitor the Policies Deployed

The integration of compliance-as-code within CI/CD pipelines is essential to shape infrastructure behavior, protect data and enforce regulations as early as possible. It helps in avoiding regulatory failures by preventing non-compliant code from going live. With such a global impact, it is critical to rigorously validate the enforced policies before deploying them widely.

Compliance policies should be tested in a controlled environment to prevent workflow disruption in production and ensure that policies are implemented correctly and are performing as expected.

To that end, a wide variety of testing methodologies can be implemented, such as static testing to verify the syntax of the policy language and confirm that no errors remain, unit testing to check each policy and rule in isolation, integration testing to test the policies' workflow in the broader infrastructure, or even regression testing to verify that implemented modifications do not break existing functionality.

Best practices for testing require writing policy test cases with the expected input and output of the policies, testing against real scenarios to validate how policies perform in practice, considering edge cases and exceptions to identify unique configuration requirements, and monitoring the implemented policies in production to address unexpected scenarios. 

Depending on the policy-as-code framework selected, built-in tools can be readily available for writing and running policy tests, which is the case for OPA and Hashicorp’s Sentinel tools.

Acknowledge Policy-as-Code Limitations and Implement Practical Solutions

When implementing a novel approach such as policy as code, it is essential to identify potential challenges upfront to address them efficiently and limit friction during deployment.

With dynamic and complex infrastructures such as the cloud, one pain point to address is the ability to accurately track and manage all implemented policies across different environments. Managing the policies deployed in these environments requires efficient policy management tools (such as Kyverno, HashiCorp’s Sentinel, or OPA) to avoid conflicting policies and overwhelming implementation teams.

Organizations might lack adequately trained personnel in-house to write and implement an efficient PaC strategy. Common languages such as YAML or Python might be used, but specialized languages like Rego or Cedar may be required for advanced use cases. As such, organizations should invest in training their workforces to address potential skill gaps they might face and develop the necessary expertise. Since training can be time-consuming and resource-intensive, they could leverage external partnerships to initiate the first steps of their policy implementation strategy and start on a solid foundation.

Adopting a policy-as-code methodology represents a cultural shift from manually enforced policies. To encourage adoption, organizations can plan a gradual and collaborative deployment. Gathering stakeholders' feedback along the process allows teams to address concerns as they arise. By focusing on high-impact areas first, such as compliance or security workflows, teams can exploit this novel approach's opportunities in terms of consistency, risk reduction, and automation.

While policy as code provides several benefits and can transform security, compliance, and governance within organizations, a methodical approach is essential for its adoption. Identifying business goals and needed policies, providing personnel with adequate training, implementing comprehensive testing, and monitoring continuously paves the way for a successful transition. By leveraging these best practices and carefully selecting the right combination of PaC tools, businesses can achieve a more secure, compliant, and resilient IT infrastructure while alleviating the friction of this transformational shift.