Extending Security Using Open Policy Agent
So far, we have covered Kubernetes' built-in authentication and authorization capabilities, which help to secure a cluster. While this will cover most use cases, it doesn't cover all of them. Several security best practices that Kubernetes can't handle are pre-authorizing container registries and ensuring that resource requests are on all Pod objects.
These tasks are left to outside systems and are called dynamic admission controllers. Open Policy Agent (OPA), and its Kubernetes native sub-project, Gatekeeper, is one of the most popular ways to handle these use cases. This chapter will detail the deployment of OPA and Gatekeeper, how OPA is architected, and how to develop policies.
In this chapter, we will cover the following topics:
- Introduction to validating webhooks
- What is OPA and how does it work?
- Using Rego to write policies
- Enforcing memory constraints
- Enforcing Pod security...
