tetragon VS gatekeeper

Many interesting software are coming from the community, many are distributed through the package manager of the operating system. But for the others, you can download them from Github release pages, use snap or homebrew to cite a few. But this last installation method bypasses the security team that tries to improve the security of your operating system. By doing so, you are implicitly trusting the author he is not distributing malware or implementing backdoors. How many tools did you install by hand? Do you really trust all of them? Confidence is very important, yet it would be nice to limit capabilities for a set of binary that you don't fully trust. In this blog post, we will use Tetragon to forbid network usage for tools that don't need to.

Falco is a cloud native Kubernetes threat detection tool. It can detect unexpected behavior, intrusions, and data theft in real time. In the backend, it uses Linux eBPF technology to trace your system and applications at runtime. For example, it can detect if someone tries to read a secret file inside a container, access a pod as a root user, etc, and trigger a webhook or send logs to the monitoring system. There are similar tools like Tetragon, KubeArmor, and Tracee which also provide Kubernetes runtime security.

When the Gatekeeper validatingwebhook came up, I was really worried that'd be the issue! Regardless I'd recommend anyone who cares about their cluster not collapsing to change the gatekeeper webhook to only intercept resources you care about: https://github.com/open-policy-agent/gatekeeper/pull/1806

Kyverno adds an extra layer of security where only the allowed type of manifest is deployed onto kubernetes, otherwise, it will reject or we can set validationFailureAction to audit which only logs the policy violation message for reporting. Kubewarden and Gatekeeper are alternative tools available to enforce policies on Kubernetes CRD.

Now, we have the hardest part resolved and let's turn our attention to the OPA Gatekeeper. Gatekeeper uses the OPA Constraint Framework to describe and enforce policy. Right now there are mainly 3 parts we should pay attention:

They enable you to establish the policies and regulations that govern cluster deployments and applications. Using predefined policies, policy engines can dynamically modify or create configurations. Policy engines such as Gatekeeper and Kyverno can be leveraged to meet legal and compliance requirements while maintaining operational flexibility and development speed.

Setup policy around what resource requirements can be requested by an app per environment. OPA and gatekeeper or kyverno can help. Setup access control for who can create or modify apps.

OPA Gatekeeper is an open source, general purpose policy engine. OPA decouples policy decisions from other responsibilities of an application, like those commonly referred to as business logic. OPA works equally well making decisions for Kubernetes, Microservices, functional application authorization and more, thanks to its single unified policy language.