ensure kubeconfig user can access cluster

images/installer/root/usr/local/bin/generate

@@ -99,6 +99,10 @@ class OpenShiftClient:
         call_cmd = 'login {host} -u {u} -p none --config {c}'
         return self.call(call_cmd.format(host=host, u=user, c=self.kubeconfig))
 
+    def whoami(self):
+        """Retrieve information about the current user in the given kubeconfig"""
+        return self.call('whoami')
+
     def get_nodes(self):
         """Retrieve remote node information as a yaml object"""
         return self.call('get nodes -o yaml')
@@ -250,7 +254,7 @@ def main():
         print "Bind-mounted host master configuration file is not of 'kind' MasterConfig. Aborting..."
         exit(1)
 
-    # finish reading config file and begin gathering 
+    # finish reading config file and begin gathering
     # cluster information for inventory file
     file_obj.close()
 
@@ -273,7 +277,7 @@ def main():
     asset_config = y.get("assetConfig")
     master_config = y.get("kubernetesMasterConfig")
     etcd_config = y.get("etcdClientInfo")
-    
+
     # if master_config is missing, error out; we expect to be running on a master to be able to
     # gather enough information to generate the rest of the inventory file.
     if not master_config:
@@ -287,8 +291,19 @@ def main():
         print msg.format(master_config_path)
         exit(1)
 
-    # connect to remote host using `oc login...` and extract all possible node information
     oc = OpenShiftClient(admin_kubeconfig_path)
+
+    # ensure kubeconfig is logged in with provided user, or fail with a friendly message otherwise
+    try:
+        oc.whoami()
+    except OpenShiftClientError as err:
+        msg = ("Unable to obtain user information using the provided kubeconfig file. "
+               "User '{}' does not appear to be logged in, or to have correct authorization. "
+               "Error returned from server:\n\n{}")
+        print msg.format(openshift_cluster_user, str(err))
+        exit(1)
+
+    # connect to remote host using the provided config and extract all possible node information
     nodes_config = yaml.load(oc.get_nodes())
 
     # contains host types (e.g. masters, nodes, etcd)