What's the hostname of openshift master server for internal access?

user_671639 0
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If I want to access the REST API of the openshift master server from anywhere in my company I use https://master.test04.otc-test.company.com:8443 which works just fine.

Now I'm writing an admin application that is accessing the REST API and is deployed in this openshift cluster. Is there a generic name or environment variable in openshift to get the hostname of the master server?

Background: My admin application will be deployed on multiple openshift clusters which do not have the same URL. It would be very handy to have them autodiscover the hostname of the current master server instead of configuring this value for every deployment.

openshift rest
1 Answers

Use environment variables:

https://$KUBERNETES_SERVICE_HOST:$KUBERNETES_SERVICE_PORT

In the container, unless service account details are not being mounted, you can also access the directory:

/var/run/secrets/kubernetes.io/serviceaccount

In this you can then find a token file which contains the access token for the service account the container runs as. This means you can create a separate service account for the application in that project, and use RBAC to control what it can do via the REST API.

That same directory also has a namespace file so you know what project the container is running in, and files with certificates to use when accessing the REST API over a secure connection.

This is the recommended approach, rather than trying to pass an access token to your application through its configuration.

Note that in OpenShift 4, if you need to access the OAuth server endpoint, it is on a separate URL to what the REST API is. In 3.X, they were on the same URL.

In 4.0, you can access the path /.well-known/oauth-authorization-server on the REST API URL, to get information about the separate OAuth server endpoint.

For additional information on giving REST API access to an application via a service account, see:

Note that that page currently says you can use https://openshift.default.svc.cluster.local as URL, but this doesn't work in OpenShift 4.

user_1281410
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