origin: Improve high level yaml/json parsing and error handling

Sometimes well-formed yaml/json files don’t conform to openshift/kubernetes data structure. My DeploymentConfig was missing containers key and as a result I got a cryptic yaml parsing error: DeploymentConfig: only encoded map or array can be decoded into a struct. The error is too vague to novice users.

Version

openshift v3.3.0.4 kubernetes v1.3.0+57fb9ac etcd 2.3.0+git

Steps To Reproduce

    template:
      metadata:
        labels:
          name: ${NAME}
        name: ${NAME}
      spec:
       containers:
       - image: docker.io/hawkularqe/hawkular-services:latest

remove containers:

Current Result

DeploymentConfig in version “v1” cannot be handled as a DeploymentConfig: only encoded map or array can be decoded into a struct.

Expected Result

A friendly message such as “Missing Containers object” would greatly improve the user experience.