So far we don't return proper http status code every time from backend and also we don't respond with error message. Usually we respond with 500 and no error message. So there is also some work needed on backend. Some initial work started here [1]. This task could be little bit more complex as error returned e.g. from library interacting with OpenShift does not contain the error code. So if we want to be correct we should also examine error returned from library on backend and decide what response code we should return. If this is not that important we can just pick most probable error type for certain call. After all the most important for the user is the error message returned (shown in the UI) and only way for user to determine the error code returned would be via browser console.

There is separate task to show the error notifications in UI [2].

[1] https://github.com/aerogear/mobile-developer-console/pull/75/files
[2] https://issues.jboss.org/browse/AEROGEAR-7964