added an 'ignore_errors' option to tasks

Failed tasks with ignore_errors=True, allow the remaining tasks in the
play to be executed as if no failure happened. A failure notice is still
written to the output as well as an '...ignoring' message.

lib/ansible/callbacks.py

@@ -259,7 +259,7 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
         else:
             print "fatal: [%s] => %s" % (host, msg)
 
-    def on_failed(self, host, results):
+    def on_failed(self, host, results, ignore_errors):
 
         item = results.get('item', None)
 
@@ -269,6 +269,8 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
             msg = "failed: [%s] => %s" % (host, utils.jsonify(results))
 
         print stringc(msg, 'red')
+        if ignore_errors:
+            print stringc("...ignoring", 'yellow')
 
     def on_ok(self, host, host_result):
 

lib/ansible/playbook/task.py

@@ -23,13 +23,13 @@ class Task(object):
     __slots__ = [ 
         'name', 'action', 'only_if', 'async_seconds', 'async_poll_interval',
         'notify', 'module_name', 'module_args', 'module_vars', 
-        'play', 'notified_by', 'tags', 'with_items', 'first_available_file'
+        'play', 'notified_by', 'tags', 'with_items', 'first_available_file', 'ignore_errors'
     ]
 
     # to prevent typos and such
     VALID_KEYS = [
          'name', 'action', 'only_if', 'async', 'poll', 'notify', 'with_items', 'first_available_file',
-         'include', 'tags'
+         'include', 'tags', 'ignore_errors'
     ]
 
     def __init__(self, play, ds, module_vars=None):
@@ -62,6 +62,7 @@ class Task(object):
         self.notify = ds.get('notify', [])
         self.first_available_file = ds.get('first_available_file', None)
         self.with_items = ds.get('with_items', None)
+        self.ignore_errors = ds.get('ignore_errors', False)
         
         # notify can be a string or a list, store as a list
         if isinstance(self.notify, basestring):
@@ -97,6 +98,9 @@ class Task(object):
             self.with_items = [ ]
         self.module_vars['items'] = self.with_items
 
+        # make ignore_errors accessable to Runner code
+        self.module_vars['ignore_errors'] = self.ignore_errors
+
         # tags allow certain parts of a playbook to be run without running the whole playbook
         apply_tags = ds.get('tags', None)
         if apply_tags is not None:

lib/ansible/runner/__init__.py

@@ -602,7 +602,13 @@ class Runner(object):
             if 'skipped' in data:
                 self.callbacks.on_skipped(result.host)
             elif not result.is_successful():
-                self.callbacks.on_failed(result.host, data)
+                ignore_errors = self.module_vars['ignore_errors']
+                self.callbacks.on_failed(result.host, data, ignore_errors)
+                if ignore_errors:
+                    if 'failed' in result.result:
+                        result.result['failed'] = False
+                    if 'rc' in result.result:
+                        result.result['rc'] = 0
             else:
                 self.callbacks.on_ok(result.host, data)
         return result