Assert pre and post conditions of all commands in test-cmd.sh

`hack/test-cmd.sh` contains a list of `kubectl` commands to test.
However, the effect of the execution of those commands was not systematically
checked. As a consequence, it was possible to break a command without breaking
those tests.

This commit surrounds every single `kubectl` command with assertions on
pre and post condition.

hack/lib/test.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+
+# Copyright 2015 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# A set of helpers for tests
+
+readonly reset=$(tput sgr0)
+readonly  bold=$(tput bold)
+readonly black=$(tput setaf 0)
+readonly   red=$(tput setaf 1)
+readonly green=$(tput setaf 2)
+
+kube::test::clear_all() {
+  kubectl delete rc,pods --all
+}
+
+kube::test::get_object_assert() {
+  local object=$1
+  local request=$2
+  local expected=$3
+
+  res=$(kubectl get $object -o template -t "$request")
+
+  if [[ "$res" =~ ^$expected$ ]]; then
+      echo -n ${green}
+      echo "Successful get $object $request: $res"
+      echo -n ${reset}
+      return 0
+  else
+      echo ${bold}${red}
+      echo "FAIL!"
+      echo "Get $object $request"
+      echo "  Expected: $expected"
+      echo "  Got:      $res"
+      echo ${reset}${red}
+      caller
+      echo ${reset}
+      return 1
+  fi
+}