adding lookup plugin for chef_databags (#18403)

* adding lookup plugin for chef_databags

* add missing classes for code-smell

lib/ansible/plugins/lookup/chef_databag.py

@@ -0,0 +1,98 @@
+# (c) 2016, Josh Bradley <jbradley(at)digitalocean.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+"""
+
+USAGE: {{ lookup('chef_databag', 'name=data_bag_name item=data_bag_item') }}
+
+NOTES: This is a lookup plugin to provide access to chef data bags using the
+       pychef package. It interfaces with the chef server api using the same
+       methods to find a knife or chef-client config file to load parameters
+       from, starting from either the given base path or the current working
+       directory. The lookup order mirrors the one from Chef, all folders in
+       the base path are walked back looking for the following configuration
+       file in order : .chef/knife.rb, ~/.chef/knife.rb, /etc/chef/client.rb
+
+Requires: pychef package: https://pychef.readthedocs.io `pip install pychef`
+
+"""
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+from ansible.errors import AnsibleError
+from ansible.plugins.lookup import LookupBase
+from ansible.parsing.splitter import parse_kv
+
+try:
+    import chef
+    HAS_CHEF = True
+except ImportError as missing_module:
+    HAS_CHEF = False
+
+
+class LookupModule(LookupBase):
+    """
+    Chef data bag lookup module
+    """
+    def __init__(self, loader=None, templar=None, **kwargs):
+
+        super(LookupModule, self).__init__(loader, templar, **kwargs)
+
+        # setup vars for data bag name and data bag item
+        self.name = None
+        self.item = None
+
+    def parse_kv_args(self, args):
+        """
+        parse key-value style arguments
+        """
+
+        for arg in ["name", "item"]:
+            try:
+                arg_raw = args.pop(arg, None)
+                if arg_raw is None:
+                    continue
+                parsed = str(arg_raw)
+                setattr(self, arg, parsed)
+            except ValueError:
+                raise AnsibleError(
+                    "can't parse arg {}={} as string".format(arg, arg_raw)
+                )
+        if args:
+            raise AnsibleError(
+                "unrecognized arguments to with_sequence: %r" % args.keys()
+            )
+
+    def run(self, terms, variables=None, **kwargs):
+        # Ensure pychef has been loaded
+        if not HAS_CHEF:
+            raise AnsibleError('PyChef needed for lookup plugin, try `pip install pychef`')
+
+        for term in terms:
+            self.parse_kv_args(parse_kv(term))
+
+        api_object = chef.autoconfigure()
+
+        if not isinstance(api_object, chef.api.ChefAPI):
+            raise AnsibleError('Unable to connect to Chef Server API.')
+
+        data_bag_object = chef.DataBag(self.name)
+
+        data_bag_item = data_bag_object[self.item]
+
+        return [dict(data_bag_item)]