Initial work on refactoring Nulecule config. #524

- Create a class representation for config data
- Implement load() to load config data for a component, taking into account answers and user supplied data
- Implement context() method to render flattened data to be consumed in a  component artifact.

Author: rtnpro

atomicapp/nulecule/config.py

@@ -0,0 +1,71 @@
+import copy
+import logging
+
+from atomicapp.constants import (NAME_KEY,
+                                 GLOBAL_CONF,
+                                 DEFAULTNAME_KEY,
+                                 LOGGER_COCKPIT)
+from atomicapp.utils import Utils
+from collections import defaultdict
+
+cockpit_logger = logging.getLogger(LOGGER_COCKPIT)
+
+
+class Config(object):
+    """
+    Store config data for a Nulecule or Nulecule component.
+    """
+
+    def __init__(self, namespace='', params=None, answers=None, cli=None,
+                 data=None, is_nulecule=False):
+        self._namespace = namespace
+        self._parent_ns, self._current_ns = self._split_namespace(self._namespace)
+        self._params = params or {}
+        self._answers = answers or defaultdict(dict)
+        self._cli = cli or {}
+        self._data = data or defaultdict(dict)
+        self._is_nulecule = is_nulecule or False
+
+    def load(self, ask=False, skip_asking=False):
+        """
+        Load config data.
+        """
+        for param in self._params:
+            value = self._answers[self._namespace].get(param[NAME_KEY]) or \
+                self._answers[self._parent_ns].get(param[NAME_KEY]) or \
+                self._answers[GLOBAL_CONF].get(param[NAME_KEY])
+            if value is None and (ask or (
+                    not skip_asking and param.get(DEFAULTNAME_KEY) is None)):
+                cockpit_logger.info("%s is missing in answers.conf." % param[NAME_KEY])
+                value = Utils.askfor(param[NAME_KEY], param)
+            elif value is None:
+                value = param.get(DEFAULTNAME_KEY)
+            self._data[self._namespace][param[NAME_KEY]] = value
+
+    def _split_namespace(self, namespace):
+        """
+        Split namespace to get parent and current namespace in a Nulecule.
+        """
+        if self._is_nulecule:
+            return '', namespace
+        words = namespace.rsplit('.', 1)
+        parent, current = '', ''
+        if len(words) == 2:
+            parent, current = words[0], words[1]
+        else:
+            parent, current = '', words[0]
+        return parent, current
+
+    def context(self):
+        """
+        Get context to render artifact files in a Nulecule component.
+        """
+        context = {}
+
+        context.update(copy.copy(self._data[GLOBAL_CONF]))
+        context.update(copy.copy(self._data[self._namespace]))
+
+        context.update(copy.copy(self._answers[GLOBAL_CONF]))
+        context.update(copy.copy(self._answers[self._namespace]))
+
+        return context