clean up first_found to fix a few issues:

- add a skip option so it won't raise an exception if you don't match anything
 - make it work as a drop-in replacement for first_available_file
 - document in the module comments all of the above cases

lib/ansible/runner/lookup_plugins/first_found.py

@@ -63,9 +63,46 @@
 #    with_first_found:
 #     - files: generic
 #       paths: tasks/staging tasks/production
-
 # this will include the tasks in the file generic where it is found first (staging or production)
 
+# example simple file lists
+#tasks:
+#- name: first found file
+#  action: copy src=$item dest=/etc/file.cfg
+#  with_first_found:
+#  - files: foo.${inventory_hostname} foo
+
+
+# example skipping if no matched files
+# First_found also offers the ability to control whether or not failing
+# to find a file returns an error or not
+#
+#- name: first found file - or skip
+#  action: copy src=$item dest=/etc/file.cfg
+#  with_first_found:
+#  - files: foo.${inventory_hostname}
+#    skip: true
+
+# the above will return an empty list if the files cannot be found at all
+# if skip is unspecificed or if it is set to false then it will return a list 
+# error which can be caught bye ignore_errors: true for that action.
+
+# finally - if you want you can use it, in place to replace first_available_file:
+# you simply cannot use the - files, path or skip options. simply replace
+# first_available_file with with_first_found and leave the file listing in place
+#
+#
+#  - name: with_first_found like first_available_file
+#    action: copy src=$item dest=/tmp/faftest
+#    with_first_found:
+#     - ../files/foo
+#     - ../files/bar
+#     - ../files/baz
+#    ignore_errors: true
+  
+
+
+
 from ansible import utils, errors
 import os
 
@@ -79,11 +116,19 @@ class LookupModule(object):
         terms = utils.listify_lookup_plugin_terms(terms, self.basedir, inject) 
 
         result = None
+        anydict = False
+        skip = False
 
+        for term in terms:
+            if isinstance(term, dict):
+                anydict = True
+        
+        if anydict:
             for term in terms:
                 if isinstance(term, dict):
                     files = term.get('files', [])
                     paths = term.get('paths', [])
+                    skip  = utils.boolean(term.get('skip', False))
                 
                     filelist = files
                     if isinstance(files, basestring):
@@ -111,6 +156,8 @@ class LookupModule(object):
                                 total_search.append(f)
                 else:
                     total_search = [term]
+        else:
+            total_search = terms
 
         result = None
         for fn in total_search:
@@ -120,4 +167,8 @@ class LookupModule(object):
 
 
         if not result:
-            raise errors.AnsibleError("no match found: %s, %s" % (pathlist, filelist))
+            if skip:
+                return []
+            else:
+                return [None]
+