Add validation for replicas

[savitaashture]

Changes

1. Add changes to validate invalid replicas specified by user as part of eventlistener spec.
2. Modified in order not to show replicas field after EL creation when replicas are not specified as part of EL spec.

Fix: #716

Signed-off-by: Savita Ashture sashture@redhat.com

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• Includes tests (if functionality changed/added)
• Includes docs (if user facing)
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Release Notes

EventListener spec validation ensures proper validation when user specifies spec.replicas values as negative or zero
ex:

cat <<EOF | kubectl create -f -
apiVersion: triggers.tekton.dev/v1alpha1
kind: EventListener
metadata:
  name: bitbucket-listener
spec:
  serviceAccountName: tekton-triggers-bitbucket-sa
  replicas: 0
  triggers:
    - name: bitbucket-triggers
      bindings:
        - ref: bitbucket-binding
      template:
        name: bitbucket-template
EOF

Gives response like below

Error from server (BadRequest): error when creating "STDIN": admission webhook "validation.webhook.triggers.tekton.dev" denied the request: validation failed: invalid value: 0: spec.replicas

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/apis/triggers/v1alpha1/event_listener_validation.go	93.1%	93.3%	0.2

[khrm]

/lgtm

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/apis/triggers/v1alpha1/event_listener_validation.go	93.1%	93.4%	0.3

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/apis/triggers/v1alpha1/event_listener_validation.go	93.1%	93.4%	0.3

[savitaashture]

/test pull-tekton-triggers-integration-tests

[dibyom]

/test pull-tekton-triggers-integration-tests

Thanks @savitaashture
This is a feature right? So, we should add something to the release notes section.

[dibyom]

/lgtm

[savitaashture]

This is a feature right? So, we should add something to the release notes section.

@dibyom Yes this is a feature
Updated release notes section

Thank you

[savitaashture]

/kind feature

[dibyom]

/test pull-tekton-triggers-integration-tests

[dibyom]

/approve

[tekton-robot]

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