Add ability to set puppet Exec timeout and to do a "dry run"

This patch allows setting "global" settings in puppet templates and
implements the "timeout" global setting for controlling the timeout
for puppet's Exec resource. In addition, a "dry run" setting that
generates manifests for development purposes but doesn't actually
apply them, is added.

Change-Id: I5a845a6569aec7188093abfdf354e46fee8c274c

packstack/modules/ospluginutils.py

@@ -39,6 +39,7 @@ class ManifestFiles(object):
     def __init__(self):
         self.filelist = []
         self.data = {}
+        self.global_data = None
 
     # continuous manifest file that have the same marker can be
     # installed in parallel, if on different servers
@@ -58,12 +59,15 @@ class ManifestFiles(object):
         Write out the manifest data to disk, this should only be called once
         write before the puppet manifests are copied to the various servers
         """
+        if not self.global_data:
+            with open(os.path.join(PUPPET_TEMPLATE_DIR, "global.pp")) as gfp:
+                self.global_data = gfp.read() % controller.CONF
         os.mkdir(basedefs.PUPPET_MANIFEST_DIR, 0700)
         for fname, data in self.data.items():
             path = os.path.join(basedefs.PUPPET_MANIFEST_DIR, fname)
             fd = os.open(path, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0600)
             with os.fdopen(fd, 'w') as fp:
-                fp.write(data)
+                fp.write(self.global_data + data)
 manifestfiles = ManifestFiles()