Implement omit for module args, also add tests for it

lib/ansible/runner/__init__.py

@@ -624,6 +624,7 @@ class Runner(object):
         inject['defaults']    = self.default_vars
         inject['environment'] = self.environment
         inject['playbook_dir'] = os.path.abspath(self.basedir)
+        inject['omit']        = OMIT_PLACE_HOLDER
 
         # template this one is available, callbacks use this
         delegate_to = self.module_vars.get('delegate_to')
@@ -867,11 +868,8 @@ class Runner(object):
 
         # allow module args to work as a dictionary
         # though it is usually a string
-        if type(module_args) == dict:
-            new_args = []
-            for (k, v) in module_args.iteritems():
-                new_args.append("%s='%s'" % (k, v))
-            module_args = ' '.join(new_args)
+        if isinstance(module_args, dict):
+            module_args = utils.serialize_args(module_args)
 
         # render module_args and complex_args templates
         try:
@@ -893,13 +891,16 @@ class Runner(object):
         except jinja2.exceptions.UndefinedError, e:
             raise errors.AnsibleUndefinedVariable("One or more undefined variables: %s" % str(e))
 
-        # filter omitted arguments out
-        new_complex_args = {}
-        for key, value in complex_args.iteritems():
-            if value == OMIT_PLACE_HOLDER:
-                continue
-            new_complex_args[key] = value
-        complex_args = new_complex_args
+        def not_omitted(item):
+            return item[1] != OMIT_PLACE_HOLDER
+
+        if module_name not in ['shell', 'command']:
+            # filter omitted arguments out from complex_args
+            complex_args = dict(filter(not_omitted, complex_args.iteritems()))
+            # filter omitted arguments out from module_args
+            module_kv = utils.parse_kv(module_args)
+            module_kv = dict(filter(not_omitted, module_kv.iteritems()))
+            module_args = utils.serialize_args(module_kv)
 
         result = handler.run(conn, tmp, module_name, module_args, inject, complex_args)
         # Code for do until feature

lib/ansible/runner/filter_plugins/core.py

@@ -32,7 +32,6 @@ from ansible.utils import md5s, OMIT_PLACE_HOLDER
 from distutils.version import LooseVersion, StrictVersion
 from random import SystemRandom
 from jinja2.filters import environmentfilter
-from jinja2.runtime import Undefined
 
 
 def to_nice_yaml(*a, **kw):
@@ -239,12 +238,6 @@ def rand(environment, end, start=None, step=None):
         raise errors.AnsibleFilterError('random can only be used on sequences and integers')
 
 
-def default_omit(a):
-    if isinstance(a, Undefined):
-        return OMIT_PLACE_HOLDER
-    return a
-
-
 class FilterModule(object):
     ''' Ansible core jinja2 filters '''
 
@@ -316,6 +309,4 @@ class FilterModule(object):
 
             # random numbers
             'random': rand,
-
-            'default_omit': default_omit,
         }

lib/ansible/utils/__init__.py

@@ -787,6 +787,10 @@ def _validate_both_dicts(a, b):
             "failed to combine variables, expected dicts but got a '%s' and a '%s'" % (type(a).__name__, type(b).__name__)
         )
 
+def serialize_args(args):
+    ''' convert a dict to a string of key/value items '''
+    return ' '.join("%s='%s'" % item for item in args.iteritems())
+
 def merge_hash(a, b):
     ''' recursively merges hash b into a
     keys from b take precedence over keys from a '''

test/integration/roles/test_good_parsing/tasks/main.yml

@@ -172,3 +172,32 @@
   assert:
     that:
       - nested_include_var is undefined
+
+- name: test omit in complex args
+  set_fact:
+    foo: bar
+    spam: "{{ omit }}"
+    should_not_omit: "prefix{{ omit }}"
+
+- assert:
+    that:
+      - foo == 'bar'
+      - spam is undefined
+      - should_not_omit == "prefix{{ omit }}"
+
+- name: test omit in module args
+  set_fact: >
+    yo=whatsup
+    eggs="{{ omit }}"
+    default_omitted="{{ not_exists|default(omit) }}"
+    should_not_omit_1="prefix{{ omit }}"
+    should_not_omit_2="{{ omit }}suffix"
+
+- assert:
+    that:
+      - yo == 'whatsup'
+      - eggs is undefined
+      - default_omitted is undefined
+      - should_not_omit_1 == "prefix{{ omit }}"
+      - should_not_omit_2 == "{{ omit }}suffix"
+