Overview of Namespace Provisioner

Namespace Provisioner provides a secure, automated way for you to provision namespaces with the resources and namespace-level privileges required for your workloads to function as intended in Tanzu Application Platform (commonly known as TAP).

Description

Namespace Provisioner enables platform operators to add additional customized namespace-scoped resources using GitOps to meet their organization’s requirements and provides continuous reconciliation using the kapp-controller to maintain the desired state of the namespace-scoped resources.

Namespace Provisioner enables operators that are new to Kubernetes to automate the provisioning of multiple developer namespaces in a shared cluster. For organizations that have already adopted Kubernetes, Namespace Provisioner is also compatible with existing Kubernetes tooling.

Modes

Use Namespace Provisioner with one of the following modes:

Controller mode

Controller mode has the following characteristics:

• The list of developer namespaces is managed by the Namespace Provisioner controller using a label selector apps.tanzu.vmware.com/tap-ns=""
• Namespace Provisioner creates default resources in all managed namespaces.
• Namespace Provisioner creates additional Platform Operator templated resources stored in Git repository locations specified under the additional_sources section in Namespace Provisioner configuration. For more information, see Customize Installation of Namespace Provisioner.

GitOps mode

Gitops mode has the following characteristics

• The list of developer namespaces is managed in a Git repository that is specified in the gitops_install section of the Namespace Provisioner configuration.
• Namespace Provisioner creates default resources that are shipped Out of the Box in all managed namespaces.
• Namespace Provisioner creates additional Platform Operator templated resources stored in Git repositories specified under additional_sources in Namespace Provisioner configuration. For more information, see Customize Installation of Namespace Provisioner.

Provisioner Carvel application

Namespace Provisioner consists of a Carvel application called provisioner that facilitates the creation of resources in the managed developer namespaces. The provisioner application uses ytt to templatize a set of resources into installations in multiple namespaces.

Desired namespaces

The following section describes how the list of desired developer namespaces is managed in controller and GitOps modes.

Controller mode

In controller mode, the list of desired namespaces used by the provisioner application to create resources in, is maintained in the desired-namespaces ConfigMap. This ConfigMap is managed by the Namespace Provisioner controller and it provides a declarative way to indicate which namespaces should be populated with resources. The ConfigMap consists of a list of namespace objects, with a required name parameter, and optional additional parameters which are used as data.values for customizing defined resources.

For example,

---
apiVersion: v1
kind: ConfigMap
metadata:
    name: desired-namespaces
    namespace: tap-namespace-provisioning
    annotations:
        kapp.k14s.io/create-strategy: fallback-on-update
        namespace-provisioner.apps.tanzu.vmware.com/no-overwrite: "" #! This annotation tells the provisioner app to not override this configMap as this is your desired state.
data:
    namespaces.yaml: |
        #@data/values
        ---
        namespaces:
        - name: dev-ns1
        # additional parameters about dev-ns1 added via label/annotations or GitOps
        - name: dev-ns2
        # additional parameters about dev-ns1 added via label/annotations or GitOps

GitOps mode

In the GitOps mode, the list of desired namespaces used by the provisioner application to create resources in, is maintained in a Git repository as a ytt data values file as shown in this sample file. This file provides a declarative way to indicate which namespaces should be populated with resources. For more information, see the Options if using GitOps section in Customize Install.

Namespace Provisioner controller

The Namespace Provisioner controller (controller) is installed by default and manages the content contained in the desired-namespaces ConfigMap. The controller watches namespaces in the cluster and updates the desired-namespaces ConfigMap with a list of all namespaces that match the namespace label selector.The defalut namespace label selector is apps.tanzu.vmware.com/tap-ns. For more information, see Use a different label selector than default.