Install tekton operator in air-gapped network

[lmgsaenz]

Feature request

Currently in tekton-operator deployment you can pass variables such as:

• IMAGE_PIPELINES_TEKTON_PIPELINES_CONTROLLER
• IMAGE_PIPELINES_WEBHOOK
• etc...

And this way you can install all the necessary components except the dashboard, so the ideal would be to also add the logic to be able to define the dashboard image variable.

This configuration is necessary to be able to enjoy Tekton in more restrictive environments that do not have internet access.

Use case

Although images can be defined in this way, it should be possible to create a new flow that is more intuitive, using for example tektonConfig:

apiVersion: operator.tekton.dev/v1alpha1
kind: TektonConfig
metadata:
  name: config
spec:
  profile: all
  targetNamespace: tekton-pipelines
  registry_url: localregistry.com/
  pipeline:
    controller_image: pipelines/controller:0.55.0
    webhook_image: pipelines/webhook:0.55.0
  dashboard:
    dashboard_image: dashboard/dashboard:0.42