Managing non-versioned and versioned cluster tasks | Creating CI/CD pipelines

Differences between non-versioned and versioned cluster tasks
Advantages and disadvantages of non-versioned and versioned cluster tasks
Disabling non-versioned and versioned cluster tasks

As a cluster administrator, installing the Red Hat OpenShift Pipelines Operator creates variants of each default cluster task known as versioned cluster tasks (VCT) and non-versioned cluster tasks (NVCT). For example, installing the Red Hat OpenShift Pipelines Operator v1.7 creates a buildah-1-7-0 VCT and a buildah NVCT.

Both NVCT and VCT have the same metadata, behavior, and specifications, including params, workspaces, and steps. However, they behave differently when you disable them or upgrade the Operator.

In Red Hat OpenShift Pipelines 1.10, ClusterTask functionality is deprecated and is planned to be removed in a future release.

Differences between non-versioned and versioned cluster tasks

Non-versioned and versioned cluster tasks have different naming conventions. And, the Red Hat OpenShift Pipelines Operator upgrades them differently.

Table 1. Differences between non-versioned and versioned cluster tasks
	Non-versioned cluster task	Versioned cluster task
Nomenclature	The NVCT only contains the name of the cluster task. For example, the name of the NVCT of Buildah installed with Operator v1.7 is `buildah`.	The VCT contains the name of the cluster task, followed by the version as a suffix. For example, the name of the VCT of Buildah installed with Operator v1.7 is `buildah-1-7-0`.
Upgrade	When you upgrade the Operator, it updates the non-versioned cluster task with the latest changes. The name of the NVCT remains unchanged.	Upgrading the Operator installs the latest version of the VCT and retains the earlier version. The latest version of a VCT corresponds to the upgraded Operator. For example, installing Operator 1.7 installs `buildah-1-7-0` and retains `buildah-1-6-0`.

Advantages and disadvantages of non-versioned and versioned cluster tasks

Before adopting non-versioned or versioned cluster tasks as a standard in production environments, cluster administrators might consider their advantages and disadvantages.

Table 2. Advantages and disadvantages of non-versioned and versioned cluster tasks
Cluster task	Advantages	Disadvantages
Non-versioned cluster task (NVCT)	If you prefer deploying pipelines with the latest updates and bug fixes, use the NVCT. Upgrading the Operator upgrades the non-versioned cluster tasks, which consume fewer resources than multiple versioned cluster tasks.	If you deploy pipelines that use NVCT, they might break after an Operator upgrade if the automatically upgraded cluster tasks are not backward-compatible.
Versioned cluster task (VCT)	If you prefer stable pipelines in production, use the VCT. The earlier version is retained on the cluster even after the later version of a cluster task is installed. You can continue using the earlier cluster tasks.	If you continue using an earlier version of a cluster task, you might miss the latest features and critical security updates. The earlier versions of cluster tasks that are not operational consume cluster resources. * After it is upgraded, the Operator cannot manage the earlier VCT. You can delete the earlier VCT manually by using the `oc delete clustertask` command, but you cannot restore it.

Disabling non-versioned and versioned cluster tasks

As a cluster administrator, you can disable cluster tasks that the OpenShift Pipelines Operator installed.

Procedure

To delete all non-versioned cluster tasks and latest versioned cluster tasks, edit the TektonConfig custom resource definition (CRD) and set the clusterTasks parameter in spec.addon.params to false.
Example TektonConfig CR
```
apiVersion: operator.tekton.dev/v1alpha1
kind: TektonConfig
metadata:
  name: config
spec:
  params:
  - name: createRbacResource
    value: "false"
  profile: all
  targetNamespace: openshift-pipelines
  addon:
    params:
    - name: clusterTasks
      value: "false"
...
```
When you disable cluster tasks, the Operator removes all the non-versioned cluster tasks and only the latest version of the versioned cluster tasks from the cluster.

Re-enabling cluster tasks installs the non-versioned cluster tasks.
Optional: To delete earlier versions of the versioned cluster tasks, use any one of the following methods:
1. To delete individual earlier versioned cluster tasks, use the oc delete clustertask command followed by the versioned cluster task name. For example:
  $ oc delete clustertask buildah-1-6-0
2. To delete all versioned cluster tasks created by an old version of the Operator, you can delete the corresponding installer set. For example:
  $ oc delete tektoninstallerset versioned-clustertask-1-6-k98as
  If you delete an old versioned cluster task, you cannot restore it. You can only restore versioned and non-versioned cluster tasks that the current version of the Operator has created.