gatekeeper VS Kyverno

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.

Anyway, I haven’t checked for sure as I’m away from laptop but it should be possible to use something like Kyverno to block that operation. We had to do similar in the past to hotfix a bug in our CLI tool. I wrote a blog post about it that might give you an idea: https://www.giantswarm.io/blog/restricting-cluster-admin-permissions

Cosign is used for signing containers through a variety of different methods. It has strong integration with other open source tools, such as Kyverno.

cosign: https://docs.sigstore.dev/cosign/overview/ kyverno: https://kyverno.io/

Kyverno - Kubernetes Native Policy Management

You could use a policy tool like kyverno or OPA.

Kyverno is present in the management cluster;

You do still have to create a policy for every namespace, but don't have to worry about labeling individual pods. We're starting to move to Helm/kustomize for our namespaces to deploy default things like network policies to each one, and we're also starting to use kyverno more, which I think is a little more purpose built for this type of thing than metacontroller is.

I knew it was unsupported so about 6 months ago I had started an effort to switch to Kyverno, which is far better and actually supported. The version of Kyverno I was using had a v1beta1 AdmissionController. Fortunately that was in a helm chart so easily caught by pluto before my upgrade.

Kyverno Kyverno is a policy engine designed for Kubernetes, Kyverno policies can validate, mutate, and generate Kubernetes resources plus ensure OCI image supply chain security.