[solved] KongPlugin 'cors' does not add access-control-allow-origin to the response header

Kubernetes
1

Hello,

I am following https://docs.konghq.com/hub/kong-inc/cors/ to setup cors plugin for a route.

First I have KongPlugin created:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: cors
  namespace: kong
config:
  origins:
  - http://*.mydomain.com
plugin: cors

Then I have the plugin added to the Ingress:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: data-service
  namespace: common
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/strip-path: "true"
    konghq.com/plugins: cors
spec:
  rules:
    - http:
        paths:
          - path: /v1/api-data-service
            backend:
              serviceName: data-service
              servicePort: 80

However, when I call the API I don’t see anything like access-control-allow-origin in the response header:

image
image1040×343 6.22 KB

Can someone please help?

BTW - some inspection I did:

$ curl -s localhost:8001/plugins | json
{
    "next": null,
    "data": []
}

$ curl -s localhost:8001/routes/3e805d97-8d99-54af-b2be-793305c4525d | json
{
    "id": "3e805d97-8d99-54af-b2be-793305c4525d",
    "tags": null,
    "paths": [
        "/v1/api-data-service"
    ],
    "destinations": null,
    "headers": null,
    "protocols": [
        "http",
        "https"
    ],
    "created_at": 1607652789,
    "methods": null,
    "snis": null,
    "service": {
        "id": "6918b268-4fb1-5562-b4a0-d16012fb829d"
    },
    "name": "common.data-service.00",
    "updated_at": 1607652789,
    "hosts": null,
    "preserve_host": true,
    "regex_priority": 0,
    "strip_path": true,
    "sources": null,
    "response_buffering": true,
    "https_redirect_status_code": 426,
    "path_handling": "v0",
    "request_buffering": true
}

$ kubectl describe kongplugins.configuration.konghq.com cors
Name:         cors
Namespace:    kong
Labels:       <none>
Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                {"apiVersion":"configuration.konghq.com/v1","config":{"origins":["http://*.mydomain.com"]},"kind":"KongPlugin","metadata":{"annotations"...
API Version:  configuration.konghq.com/v1
Config:
  Origins:
    http://*.mydomain.com
Kind:  KongPlugin
Metadata:
  Creation Timestamp:  2020-12-11T02:00:53Z
  Generation:          5
  Managed Fields:
    API Version:  configuration.konghq.com/v1
    Fields Type:  FieldsV1
    fieldsV1:
      f:config:
        .:
        f:origins:
      f:metadata:
        f:annotations:
          .:
          f:kubectl.kubernetes.io/last-applied-configuration:
      f:plugin:
    Manager:         kubectl
    Operation:       Update
    Time:            2020-12-11T02:20:01Z
  Resource Version:  26537774
  Self Link:         /apis/configuration.konghq.com/v1/namespaces/kong/kongplugins/cors
  UID:               0a3cd227-3bdf-48bd-bfc5-0d84749ffa2d
Plugin:              cors
Events:              <none>


$ kubectl describe ingress --namespace common data-service
Name:             data-service
Namespace:        common
Address:          a097f4e169e6f4cec841753752f24d69-1322353396.ap-southeast-1.elb.amazonaws.com
Default backend:  default-http-backend:80 (<none>)
Rules:
  Host  Path  Backends
  ----  ----  --------
  *
        /v1/api-data-service   data-service:80 (10.2.0.109:9000)
Annotations:
  konghq.com/strip-path:                             true
  kubectl.kubernetes.io/last-applied-configuration:  {"apiVersion":"extensions/v1beta1","kind":"Ingress","metadata":{"annotations":{"konghq.com/plugins":"cors","konghq.com/strip-path":"true","kubernetes.io/ingress.class":"kong"},"name":"data-service","namespace":"common"},"spec":{"rules":[{"http":{"paths":[{"backend":{"serviceName":"data-service","servicePort":80},"path":"/v1/api-data-service"}]}}]}}

  kubernetes.io/ingress.class:  kong
  konghq.com/plugins:           cors
Events:                         <none>
2

It turns out I created KongPlugin in the same namespace as Kong for Kubernetes, whereas the Ingress was created in its own namespace.

I’d suggest to make that clear in the doc.