argo-events: gateway validation failed

Describe the bug calendar-gateway validation fails

To Reproduce Followed tutorials:

• https://github.com/argoproj/argo-events/blob/master/docs/quickstart.md
• https://github.com/argoproj/argo-events/blob/master/docs/tutorial.md#calendar

1. create configmap
2. create calendar gateway

When I ran $ kubectl describe gateways calendar-gateway

it says the validation failed.

Name:         calendar-gateway
Namespace:    argo-events
Labels:       gateway-name=calendar-gateway
              gateways.argoproj.io/gateway-controller-instanceid=argo-events
              sensors.argoproj.io/phase=Error
Annotations:  gateways.argoproj.io/phase=Error
API Version:  argoproj.io/v1alpha1
Kind:         Gateway
Metadata:
  Creation Timestamp:  2019-01-23T03:37:31Z
  Generation:          1
  Resource Version:    2485150
  Self Link:           /apis/argoproj.io/v1alpha1/namespaces/argo-events/gateways/calendar-gateway
  UID:                 370b9790-1ec0-11e9-9d23-062114e1fc54
Spec:
  Config Map:  calendar-gateway-configmap
  Deploy Spec:
    Metadata:
      Creation Timestamp:  <nil>
    Spec:
      Containers:  <nil>
    Status:
  Dispatch Protocol:
  Event Version:
  Processor Port:
  Type:               calendar
  Watchers:
    Sensors:
      Name:  calendar-sensor
Status:
  Message:     validation failed
  Phase:       Error
  Started At:  2019-01-23T03:37:31Z
Events:        <none>

even after creating the sensor it still fails validation

Expected behavior Seems like that gateway is not active,

Status:
  Message:     validation failed
  Phase:       Error
  Started At:  2019-01-23T03:37:31Z
Events:        <none>

Environment (please complete the following information):

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.5 LTS
Release:        16.04
Codename:       xenial

Additional context Add any other context about the problem here.

I tried running docker logs on the container metalgearsolid/gateway-controller and here’s the logs:

2019-01-23T09:24:37Z | info  | msg: operating on the gateway |  name:webhook-gateway namespace:argo-events phase:Error
2019-01-23T09:24:37Z | error | msg: gateway is in error state. please check escalated K8 event for the error |  name:webhook-gateway namespace:argo-events