build: move some of hack/lib/ into a new cluster/lib/

Some functionality in hack/lib is currently depended on by
cluster/common.sh so kube-up from the full release tar (which
does not include hack/) is currently broken. With this PR we
create cluster/lib/ and move the necessary bits from hack/
over to get kube-up working again.

Fixes: 96d1b8d1b2
Signed-off-by: Mike Danese <mikedanese@google.com>

cluster/lib/util.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+# Copyright 2015 The Kubernetes Authors 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.
+
+# Wait for background jobs to finish. Return with
+# an error status if any of the jobs failed.
+kube::util::wait-for-jobs() {
+  local fail=0
+  local job
+  for job in $(jobs -p); do
+    wait "${job}" || fail=$((fail + 1))
+  done
+  return ${fail}
+}
+