What Is Policy-as-Code?
Policy-as-code is an approach to policy management in which policies are defined, updated, shared, and enforced using code. By leveraging code-based automation instead of relying on manual processes to manage policies, policy-as-code allows teams to move more quickly and reduce the potential for mistakes due to human error.
At the same time, a policy-as-code approach to domains like security makes it possible to define and manage policies in ways that different types of stakeholders – such as developers and security engineers – can understand.
This page explains how policy-as-code works, why it’s important, and how to leverage it within the context of security.
Defining Policy-As-Code
To understand what policy-as-code means, you must first understand the definition of a “policy.”
In this context, a policy is any type of rule, condition, or instruction that governs IT operations or processes. A policy could be a rule that defines which conditions must be met in order for a code to pass a security control and be deployed, for example. Or, it could be a set of procedures that are executed automatically in response to a security event.
Policy-as-code is the use of code to define and manage rules and conditions. Under a policy-as-code approach, teams write out policies using some type of programming language, such as Python, YAML, or Rego. The specific language usually depends on which policy-as-code management and enforcement tools you are using.
When engineers need to make updates, they do so by modifying the existing code. They can also share the code with others to give them visibility into their policies using version control systems (VCS). And, last but not least, they can use a policy-as-code enforcement engine to ensure policies are met. An enforcement engine may be a standalone policy-as-code code, or it could be built into a larger platform.
Policy-as-Code vs. Infrastructure as Code
The concept of policy-as-code may sound similar to Infrastructure as Code, or IaC. IaC, which uses code-based files to automate infrastructure setup and provisioning, has been a common practice for IT operations teams for years.
Whereas IaC is beneficial to IT operations teams who need to provision infrastructure, policy-as-code can improve security operations, compliance management, data management, and far beyond.
Benefits of Policy-as-Code
Compared to the alternative – which is to manage rules, conditions, and procedures manually – policy-as-code offers several critical benefits:
- Efficiency: When policies are spelled out as code, they can be shared and enforced automatically at virtually unlimited scale. This is much more efficient than requiring engineers to enforce a policy manually each time it becomes necessary to do so. Updating and sharing policies are also more efficient when the policies are defined in clear, concise code rather than being described in human language that some engineers may interpret differently than others.
- Speed: The ability to automate policy enforcement also means that policy-as-code results in faster operations than a manual approach.
- Visibility: When policies are defined in code, it’s easy for all stakeholders to use the code to understand what is happening within a system. They can review alerting or remediation rules simply by checking which code-based policies are in place, for example, instead of having to ask other engineers and wait for a response.
- Collaboration: By providing a uniform, systematic means of managing policies, policy-as-code simplifies collaboration. This includes collaboration not just within the same team, but also between different types of teams – especially between developers (who are accustomed to thinking and working in terms of code) and specialists in other domains, like security or IT operations.
- Accuracy: When teams define and manage policies using code, they avoid the risk of making configuration mistakes when managing a system manually.
- Version control: If you keep track of different versions of your policy files as they change, policy-as-code ensures that you can revert to an earlier configuration easily in the event that a new policy version creates a problem.
- Testing and validation: When policies are written in code, it’s easy to validate them using automated auditing tools. In this way, policy-as-code can help reduce the risk of introducing critical errors into production environments.
How to Use Policy-As-Code
The easiest way to take advantage of policy-as-code today is to adopt tools that natively support policy-as-code for whichever domain you want to manage via a policy-as-code approach.
For example, in the realm of security, Prisma Cloud, Bridgecrew, and Checkov allow teams to define security policies using code. They can also automatically scan and audit policy files in order to detect misconfigurations or vulnerabilities prior to deployment. This approach is one way that these tools streamline cloud security posture management.
You may also want to explore tools like Open Policy Agent, which aims to provide a common framework for applying policy-as-code to any domain. To date, however, vendor adoption of community-based policy-as-code frameworks like this remains limited, which is why seeking out vendor tools with native policy-as-code support is the simplest path toward implementing a policy-as-code approach to security or any other IT domain.
