Add --only-if-changed option.

bin/ansible-pull

@@ -45,8 +45,9 @@ import socket
 from optparse import OptionParser
 
 DEFAULT_PLAYBOOK = 'local.yml'
-PLAYBOOK_ERRORS = { 1: 'File does not exist',
-                    2: 'File is not readable' }
+PLAYBOOK_ERRORS = {1: 'File does not exist',
+                    2: 'File is not readable'}
+
 
 def _run(cmd):
     print >>sys.stderr, "Running: '%s'" % cmd
@@ -56,7 +57,8 @@ def _run(cmd):
     print out
     if cmd.returncode != 0:
         print >>sys.stderr, err
-    return cmd.returncode
+    return cmd.returncode, out
+
 
 def try_playbook(path):
     if not os.path.exists(path):
@@ -65,6 +67,7 @@ def try_playbook(path):
         return 2
     return 0
 
+
 def select_playbook(path, args):
     playbook = None
     if len(args) > 0 and args[0] is not None:
@@ -89,12 +92,15 @@ def select_playbook(path, args):
             print >>sys.stderr, "\n".join(errors)
         return playbook
 
+
 def main(args):
     """ Set up and run a local playbook """
     usage = "%prog [options] [playbook.yml]"
     parser = OptionParser(usage=usage)
     parser.add_option('--purge', default=False, action='store_true',
                       help='Purge git checkout after playbook run')
+    parser.add_option('-o', '--only-if-changed', dest='ifchanged', default=False, action='store_true',
+                      help='Only run the playbook if the repository has been updated')
     parser.add_option('-d', '--directory', dest='dest', default=None,
                       help='Directory to clone git repository to')
     parser.add_option('-U', '--url', dest='url', default=None,
@@ -123,9 +129,12 @@ def main(args):
     cmd = 'ansible all -c local -i "%s" --limit "%s" -m git -a "%s"' % (
             inv_opts, limit_opts, git_opts
             )
-    rc = _run(cmd)
+    rc, out = _run(cmd)
     if rc != 0:
         return rc
+    elif options.ifchanged and '"changed": true' not in out:
+        print "Repository has not changed, quitting."
+        return 0
 
     playbook = select_playbook(options.dest, args)
 
@@ -137,7 +146,7 @@ def main(args):
     if options.inventory:
         cmd += ' -i "%s"' % options.inventory
     os.chdir(options.dest)
-    rc = _run(cmd)
+    rc, out = _run(cmd)
 
     if options.purge:
         os.chdir('/')