hierarchical-namespaces VS rbac-manager

HNC_VERSION=v1.1.0 HNC_VARIANT=default kubectl apply -f https://github.com/kubernetes-sigs/hierarchical-namespaces/releases/latest/download/hnc-manager.yaml

Kubernetes has a lot of limitations from a multi tenancy perspective.

It's functional, but I think it's not as polished as the rest of Kubernetes which is why Kubernetes has a multi tenancy SIG that spawned the hierarchical namespace controller (https://github.com/kubernetes-sigs/hierarchical-namespaces) and virtual clusters (https://github.com/kubernetes-sigs/cluster-api-provider-nest...)

Kyverno's a great option. Depending on the usecase you might want to consider https://github.com/kubernetes-sigs/hierarchical-namespaces as well (disclaimer: I'm the original author) - it's good if groups of related namespaces need related objects.

❯ HNC_VERSION=v1.0.0 ❯ kubectl apply -f https://github.com/kubernetes-sigs/hierarchical-namespaces/releases/download/${HNC_VERSION}/default.yaml namespace/hnc-system created customresourcedefinition.apiextensions.k8s.io/hierarchyconfigurations.hnc.x-k8s.io created customresourcedefinition.apiextensions.k8s.io/hncconfigurations.hnc.x-k8s.io created customresourcedefinition.apiextensions.k8s.io/subnamespaceanchors.hnc.x-k8s.io created role.rbac.authorization.k8s.io/hnc-leader-election-role created clusterrole.rbac.authorization.k8s.io/hnc-admin-role created clusterrole.rbac.authorization.k8s.io/hnc-manager-role created clusterrole.rbac.authorization.k8s.io/hnc-proxy-role created rolebinding.rbac.authorization.k8s.io/hnc-leader-election-rolebinding created clusterrolebinding.rbac.authorization.k8s.io/hnc-manager-rolebinding created clusterrolebinding.rbac.authorization.k8s.io/hnc-proxy-rolebinding created secret/hnc-webhook-server-cert created service/hnc-controller-manager-metrics-service created service/hnc-webhook-service created deployment.apps/hnc-controller-manager created mutatingwebhookconfiguration.admissionregistration.k8s.io/hnc-mutating-webhook-configuration created validatingwebhookconfiguration.admissionregistration.k8s.io/hnc-validating-webhook-configuration created # Install helper plugin ❯ kubectl krew install hns

I would say it’s an anti-pattern since using a namespace for multiple environments will be a pain. Not sure what you mean by CRDs though. There is an addon that gives you namespace hierarchies. I.e. each team gets a namespace and they can have sub-namespaces for environments. Check it out: https://github.com/kubernetes-sigs/hierarchical-namespaces

Looking into the Hierarchical Namespace Controller to see if it can simplify our heavily multi-tenanted clusters. So far so good!

HNC is designed for these kinds of scenarios: https://github.com/kubernetes-sigs/hierarchical-namespaces

Project HNC

While RBAC is not particularly the toughest aspect of multi-tenancy, there are tools to help you with it. RBAC Manager was developed by Fairwinds to make security just a bit easier.

We have a use case similar to this and we use rbac-manager. If you can have something externally provision the namespaces with labels, I think it might work for you. If not, maybe some combination with OPA Gatekeeper could do the trick?