Introduce exception AnsibleFilterError and use it in Jinja filters. Ignore this…

Introduce exception AnsibleFilterError and use it in Jinja filters.  Ignore this exception when trying to find the name of a task for display (callback) purpose.

lib/ansible/errors.py

@@ -35,3 +35,6 @@ class AnsibleYAMLValidationFailed(AnsibleError):
 
 class AnsibleUndefinedVariable(AnsibleError):
     pass
+
+class AnsibleFilterError(AnsibleError):
+    pass

lib/ansible/playbook/__init__.py

@@ -326,7 +326,7 @@ class PlayBook(object):
         ansible.callbacks.set_task(self.callbacks, task)
         ansible.callbacks.set_task(self.runner_callbacks, task)
 
-        self.callbacks.on_task_start(template(play.basedir, task.name, task.module_vars, lookup_fatal=False), is_handler)
+        self.callbacks.on_task_start(template(play.basedir, task.name, task.module_vars, lookup_fatal=False, filter_fatal=False), is_handler)
         if hasattr(self.callbacks, 'skip_task') and self.callbacks.skip_task:
             ansible.callbacks.set_task(self.callbacks, None)
             ansible.callbacks.set_task(self.runner_callbacks, None)

lib/ansible/runner/filter_plugins/core.py

@@ -33,7 +33,7 @@ def to_nice_json(*a, **kw):
 def failed(*a, **kw):
     item = a[0] 
     if type(item) != dict:
-        raise errors.AnsibleError("|failed expects a dictionary")
+        raise errors.AnsibleFilterError("|failed expects a dictionary")
     rc = item.get('rc',0)
     failed = item.get('failed',False)
     if rc != 0 or failed:

lib/ansible/utils/template.py

@@ -295,9 +295,10 @@ def legacy_varReplace(basedir, raw, vars, lookup_fatal=True, depth=0, expand_lis
 
 # TODO: varname is misnamed here
 
-def template(basedir, varname, vars, lookup_fatal=True, depth=0, expand_lists=True, convert_bare=False, fail_on_undefined=False):
+def template(basedir, varname, vars, lookup_fatal=True, depth=0, expand_lists=True, convert_bare=False, fail_on_undefined=False, filter_fatal=True):
     ''' templates a data structure by traversing it and substituting for other data structures '''
 
+    try:
         if convert_bare and isinstance(varname, basestring):
             first_part = varname.split(".")[0].split("[")[0]
             if first_part in vars and '{{' not in varname and '$' not in varname:
@@ -331,6 +332,11 @@ def template(basedir, varname, vars, lookup_fatal=True, depth=0, expand_lists=Tr
             return d
         else:
             return varname
+    except errors.AnsibleFilterError:
+        if filter_fatal:
+            raise
+        else:
+            return varname
 
 
 class _jinja2_vars(object):