add --step option to ansible-playbooks to let people step through a playbook

one by one - asking for confirmation along the way.

also allows to 'continue' after a certain point

bin/ansible-playbook

@@ -72,6 +72,8 @@ def main(args):
         help="do a playbook syntax check on the playbook, do not execute the playbook")
     parser.add_option('--list-tasks', dest='listtasks', action='store_true',
         help="do list all tasks that would be executed")
+    parser.add_option('--step', dest='step', action='store_true',
+        help="one-step-at-a-time: confirm each task before running")
 
     options, args = parser.parse_args(args)
 
@@ -111,6 +113,8 @@ def main(args):
 
         stats = callbacks.AggregateStats()
         playbook_cb = callbacks.PlaybookCallbacks(verbose=utils.VERBOSITY)
+        if options.step:
+            playbook_cb.step = options.step
         runner_cb = callbacks.PlaybookRunnerCallbacks(stats, verbose=utils.VERBOSITY)
 
         pb = ansible.playbook.PlayBook(

lib/ansible/callbacks.py

@@ -464,7 +464,20 @@ class PlaybookCallbacks(object):
         msg = "TASK: [%s]" % name
         if is_conditional:
             msg = "NOTIFIED: [%s]" % name
-        print banner(msg)
+
+        if hasattr(self, 'step') and self.step:
+            resp = raw_input('Perform task: %s (y/n/c): ' % name)
+            if resp.lower() in ['y','yes']:
+                self.skip_task = False
+                print banner(msg)                
+            elif resp.lower() in ['c', 'continue']:
+                self.skip_task = False
+                self.step = False
+                print banner(msg)
+            else:
+                self.skip_task = True
+        
+        
         call_callback_module('playbook_on_task_start', name, is_conditional)
 
     def on_vars_prompt(self, varname, private=True, prompt=None, encrypt=None, confirm=False, salt_size=None, salt=None, default=None):

lib/ansible/playbook/__init__.py

@@ -301,7 +301,9 @@ class PlayBook(object):
         ''' run a single task in the playbook and recursively run any subtasks.  '''
 
         self.callbacks.on_task_start(utils.template(play.basedir, task.name, task.module_vars, lookup_fatal=False), is_handler)
-
+        if hasattr(self.callbacks, 'skip_task') and self.callbacks.skip_task:
+            return True
+        
         # load up an appropriate ansible runner to run the task in parallel
         results = self._run_task_internal(task)