gatekeeper VS kubefed

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.

The project is similar (in spirit) to kubefed.

What Is KubeFed? KubeFed (Kubernetes Cluster Federation) allows you to use a single Kubernetes cluster to coordinate multiple Kubernetes clusters. It can deploy multiple-cluster applications in different regions and design for disaster recovery. To learn more about KubeFed: https://github.com/kubernetes-sigs/kubefed

There's active work on a standard called kubefed [0] that is being worked on.

> I want a scale-to-zero node-pool in every region, and one kube master api for the world.

Personally, I'd generalize this to: "I want to describe the reliability requirements and configuration for my software and have an automated system solve for where, how many, when, and how to route to it"

I want to have something where I can say "I need to have high availability, lowest latency, and X GB of RAM and Y cores" and have a system automatically schedule me wherever compute is cheapest while also intelligently routing traffic to my servers based on client origins.

[0] - https://github.com/kubernetes-sigs/kubefed

Two of the more common approaches to deploying Kubernetes in hybrid environments are from cloud-to-cloud and cloud to on-prem. Whether this is from using a single control plane like Rancher, Platform9, or Gardener to create multiple clusters that are managed from a single location, or utilizing Kubernetes federation to create a cluster that spans different regions, this model has become a key feature offered by Kubernetes that has helped drive adoption.

This is made possible by the very nature of Kubernetes being a standard portable platform across cloud providers, ability to manage infrastructure as code, ability to setup networking between them whenever needed with the help of multi-cluster service meshes and also due to the ability to orchestrate the deployments using Kubefed and Crossplane.

And the interesting thing about networking in cloud is that it need not be just be limited to the cloud provider within your region but can span across multiple providers across multiple regions as needed and this is where projects like Kubefed, Crossplane definitely does help.

Projects like Kubefed and Crossplane are especially useful here since they help you to manage and orchestrate clusters and the requests you send across different cloud providers even if its going to be across regions.