Red Hat OpenShift Container Platform

Allowing JavaScript-based access to the API server from additional hosts

If you need to access the API server or OAuth server from a JavaScript application by using a different hostname, you can configure additional hostnames to allow.

Prerequisites

Access to the cluster as a user with the cluster-admin role.

Procedure

Edit the APIServer resource:

$ oc edit apiserver.config.openshift.io cluster

Add the additionalCORSAllowedOrigins field under the spec section and specify one or more additional hostnames:

apiVersion: config.openshift.io/v1
kind: APIServer
metadata:
  annotations:
    release.openshift.io/create-only: "true"
  creationTimestamp: "2019-07-11T17:35:37Z"
  generation: 1
  name: cluster
  resourceVersion: "907"
  selfLink: /apis/config.openshift.io/v1/apiservers/cluster
  uid: 4b45a8dd-a402-11e9-91ec-0219944e0696
spec:
  additionalCORSAllowedOrigins:
  - (?i)//my\.subdomain\.domain\.com(:|\z)

where:

additionalCORSAllowedOrigins

The hostname is specified as a Golang regular expression that matches against CORS headers from HTTP requests against the API server and OAuth server.

This example uses the following syntax:

The (?i) makes it case-insensitive.
The // pins to the beginning of the domain and matches the double slash following http: or https:.
The \. escapes dots in the domain name.
The (:|\z) matches the end of the domain name (\z) or a port separator (:).

Save the file to apply the changes.