about.hbs.md

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:

![Diagram of Namespace Provisioner controller.](../images/namespace-provisioner-controller.png)

- 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](default-resources.hbs.md) 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](customize-installation.hbs.md).

GitOps mode : Gitops mode has the following characteristics

![Diagram of Namespace Provisioner.](../images/namespace-provisioner-1.png)

- 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](default-resources.hbs.md) 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](customize-installation.hbs.md).

## 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,

```yaml
---
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.