update version package when building.

hack/build-go.sh

@@ -18,6 +18,9 @@
 
 set -e
 
+# Update the version.
+$(dirname $0)/version-gen.sh
+
 source $(dirname $0)/config-go.sh
 
 cd "${KUBE_TARGET}"

hack/version-gen.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+# Copyright 2014 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.
+
+# TODO: when we start making tags, switch to git describe?
+desc=$(git rev-list --abbrev-commit --max-count=1 HEAD)
+tab=$'\t'
+script="22s/.*/${tab}commitFromGit = \`${desc}\`/"
+infile="$(dirname $0)/../pkg/version/template.go"
+outfile="$(dirname $0)/../pkg/version/autogenerated.go"
+sed "${script}" "${infile}" > "${outfile}"