Lookups: use Ansible's config manager whenever possible (#5440)

* Start using Ansible's config manager to handle options.

* Docs improvements.

* Fix documentation, make options actual lookup options.

* The cyberarkpassword lookup does too strange things.

* The onepassword lookups are converted in #4728, let's not interfere.

* Improve docs.

* Skip shelvefile as well.

* Convert lmdb_kv.

* Convert and fix credstash.

* Convert manifold.

* Drop chef_databag.

* Convert dig.

* Update examples.

* Forgot the most important part.

* Fix lmdb_kv docs.

* Python 2.6 compatibility.

* Convert AnsibleUnicode to str.

* Load lookup with lookup loader.

* Fix environment handling and error message checking.

* Improve docs formatting.

plugins/lookup/keyring.py

@@ -26,7 +26,9 @@ EXAMPLES = """
     - 'servicename username'
 
 - name: access mysql with password from keyring
-  mysql_db: login_password={{lookup('community.general.keyring','mysql joe')}} login_user=joe
+  community.mysql.mysql_db:
+    login_password: "{{ lookup('community.general.keyring', 'mysql joe') }}"
+    login_user: joe
 """
 
 RETURN = """
@@ -53,10 +55,12 @@ display = Display()
 
 class LookupModule(LookupBase):
 
-    def run(self, terms, **kwargs):
+    def run(self, terms, variables=None, **kwargs):
         if not HAS_KEYRING:
             raise AnsibleError(u"Can't LOOKUP(keyring): missing required python library 'keyring'")
 
+        self.set_options(var_options=variables, direct=kwargs)
+
         display.vvvv(u"keyring: %s" % keyring.get_keyring())
         ret = []
         for term in terms: