Create macos juju prereqs #8313

cluster/juju/macos-prereqs

@@ -0,0 +1,41 @@
+
+#!/bin/bash
+
+# Copyright 2015 The Kubernetes Authors.
+#
+# 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.
+
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+function package_status() {
+    local pkgname=$1
+    brew info ${pkgname} | grep "Not installed" > /dev/null
+    if [[ $? -eq 0 ]]; then
+        echo "Missing package ${pkgname}"
+        brew install ${pkgname}
+    fi
+}
+
+function gather_installation_reqs() {
+    brew > /dev/null
+    if [[ $? -ne 0 ]]; then
+        echo "Missing brew installer"
+        /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
+    fi
+
+    package_status 'juju'
+    package_status 'charm-tools'
+}