Teach the common module code to warn users about typo'd arguments and also set…

Teach the common module code to warn users about typo'd arguments and also set everything to None automatically such
that code doesn't have to do a lot of params.get('foo', None) everywhere.

lib/ansible/module_common.py

@@ -64,26 +64,43 @@ class AnsibleModule(object):
         self.argument_spec = argument_spec
         (self.params, self.args) = self._load_params()
 
+        self._legal_inputs = []
         self._handle_aliases()
-        self._set_defaults()
+        self._check_invalid_arguments()
+        self._set_defaults(pre=True)
 
         if not bypass_checks:
             self._check_required_arguments()
             self._check_argument_types()
+
+        self._set_defaults(pre=False)
         if not no_log:
             self._log_invocation()
 
+
     def _handle_aliases(self):
         for (k,v) in self.argument_spec.iteritems():
+            self._legal_inputs.append(k)
             aliases = v.get('aliases', None)
+            default = v.get('default', None)
+            required = v.get('required', False)
+            if default is not None and required:
+                # not alias specific but this is a good place to check this
+                self.fail_json(msg="internal error: required and default are mutally exclusive for %s" % k)
             if aliases is None:
                 continue
             if type(aliases) != list:
                 self.fail_json(msg='internal error: aliases must be a list')
             for alias in aliases:
+                self._legal_inputs.append(alias)
                 if alias in self.params:
                     self.params[k] = self.params[alias]
 
+    def _check_invalid_arguments(self):
+        for (k,v) in self.params.iteritems():
+            if k not in self._legal_inputs:
+                self.fail_json(msg="unsupported parameter for module: %s" % k)
+
     def _check_required_arguments(self):
         ''' ensure all required arguments are present '''
         missing = []
@@ -109,11 +126,17 @@ class AnsibleModule(object):
             else:
                 self.fail_json(msg="internal error: do not know how to interpret argument_spec")
 
-    def _set_defaults(self):
+    def _set_defaults(self, pre=True):
          for (k,v) in self.argument_spec.iteritems():
-             default = v.get('default', '__NO_DEFAULT__')
-             if default != '__NO_DEFAULT__' and k not in self.params:
-                 self.params[k] = default
+             default = v.get('default', None)
+             if pre == True:
+                 # this prevents setting defaults on required items
+                 if default and k not in self.params:
+                     self.params[k] = default
+             else:
+                 # make sure things without a default still get set None
+                 if k not in self.params:
+                     self.params[k] = default
 
     def _load_params(self):
         ''' read the input and return a dictionary and the arguments string '''

library/command

@@ -76,6 +76,12 @@ def main():
 
 class CommandModule(AnsibleModule):
 
+    def _handle_aliases(self):
+        pass
+
+    def _check_invalid_arguments(self):
+        pass
+
     def _load_params(self):
         ''' read the input and return a dictionary and the arguments string '''
         args = base64.b64decode(MODULE_ARGS)

library/yum

@@ -280,15 +280,13 @@ def main():
             # removed==absent, installed==present, these are accepted as aliases
             state=dict(default='installed', choices=['absent','present','installed','removed','latest']),
             list=dict(choices=['installed','updates','available','repos','pkgspec']),
+            conf_file=dict()
         )
     )
 
     params = module.params
 
-    if 'conf_file' not in params:
-        params['conf_file'] = None
-
-    if 'list' in params and 'pkg' in params:
+    if params['list'] and params['pkg']:
         module.fail_json(msg="expected 'list=' or 'name=', but not both")
     
     if 'list' in params: