Where does the environment variable is set?

3

The Wiki guide does not say much about, how RATINGS_HOSTNAME is setup or environment variables are setup.

What I am trying to achieve is, I would like to create two services, for example Foo and Boo. Foo will call Boo and it has to know the address of Boo. How can I find out the address or how to define it for Boo.

I deployed the app BookInfo on my k8s cluster and it works as expected.

Looking at the review app and how the url of the ratings app is build:

private final static String services_domain = System.getenv("SERVICES_DOMAIN") == null ? "" : ("." + System.getenv("SERVICES_DOMAIN"));
private final static String ratings_hostname = System.getenv("RATINGS_HOSTNAME") == null ? "ratings" : System.getenv("RATINGS_HOSTNAME");
private final static String ratings_service = "http://" + ratings_hostname + services_domain + ":9080/ratings";

Those environment variables have to be set somewhere before the app is deployed.

Thanks