Add dib-lint script

This will provide a place to put checks that catch common errors
in elements.  To start, this just checks that files starting with
a shebang are chmod +x so they can actually be run.

Change-Id: I4116a8f38f7bdfc5866764354c459fad8ca18e92

bin/dib-lint

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# Copyright 2014 Red Hat, Inc.
+#
+# 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.
+
+# This script checks all files in the "elements" directory for some
+# common mistakes and exits with a non-zero status if it finds any.
+
+rc=0
+for i in $(find elements -type f); do
+    # Check that files starting with a shebang are +x
+    firstline=$(head -n 1 "$i")
+    if [ ! -x "$i" ] && [ "${firstline:0:2}" = "#!" ]; then
+        echo "ERROR: $i is not executable"
+        rc=1
+    fi
+done
+exit $rc

setup.cfg

@@ -22,6 +22,7 @@ packages =
 # dib-run-parts and ramdisk-image-create are symlinks which become
 # real files on install; see lp bug #1212482
 scripts =
+    bin/dib-lint
     bin/dib-run-parts
     bin/disk-image-create
     bin/disk-image-get-kernel

tox.ini

@@ -14,6 +14,7 @@ commands=
 [testenv:pep8]
 commands =
   flake8 {posargs}
+  dib-lint
 
 [testenv:venv]
 commands = {posargs}