Add a script to validate templates

This adds a new script that can walk through a template directory and
call heat template-validate on them. It handles environment files by
expecting $template_env.ext, so it'll need renaming for the 2 templates
that we have needing that. It also needs #1298450 fixed. The goal is to
be able to use this script in a future gate.

Change-Id: I4246d494de9a3a56c3b334ba20ad06186ccaefd6

tools/validate-templates

@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+
+import os
+import subprocess
+import sys
+
+
+def main(args):
+    if len(args) != 1:
+        raise SystemExit("Takes one argument, the path to the templates")
+
+    path = args[0]
+    got_error = False
+    for root, dirs, files in os.walk(path):
+        for name in files:
+            if name.endswith((".yaml", ".template")):
+                got_error = validate(root, name)
+    sys.exit(int(got_error))
+
+
+def validate(base, name):
+    basename, ext = os.path.splitext(name)
+    if basename.endswith("_env"):
+        return
+    args = ["heat", "template-validate", "-f", os.path.join(base, name)]
+    base_env = "%s_env%s" % (basename, ext)
+    env = os.path.join(base, base_env)
+    if os.path.exists(env):
+        args.extend(["-e", env])
+    try:
+        output = subprocess.check_output(args)
+    except subprocess.CalledProcessError as e:
+        print "Got error validating %s" % name
+        return True
+    else:
+        return False
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])