Implement a fake SDL database backend

[ric-plt/sdlpy.git] / ricsdl-package / ricsdl / configuration.py

diff --git a/ricsdl-package/ricsdl/configuration.py b/ricsdl-package/ricsdl/configuration.py
index 91bcd98..892d607 100644 (file)
--- a/ricsdl-package/ricsdl/configuration.py
+++ b/ricsdl-package/ricsdl/configuration.py
@@ -21,16 +21,23 @@
 
 """The module provides implementation of Shared Data Layer (SDL) configurability."""
 import os
+from enum import Enum
 from collections import namedtuple
 
 
+class DbBackendType(Enum):
+    """Enumeration class of supported SDL database backend types."""
+    REDIS = 1
+    FAKE_DICT = 2
+
+
 class _Configuration():
     """This class implements Shared Data Layer (SDL) configurability."""
     Params = namedtuple('Params', ['db_host', 'db_port', 'db_sentinel_port',
-                                   'db_sentinel_master_name'])
+                                   'db_sentinel_master_name', 'db_type'])
 
-    def __init__(self):
-        self.params = self._read_configuration()
+    def __init__(self, fake_db_backend):
+        self.params = self._read_configuration(fake_db_backend)
 
     def __str__(self):
         return str(
@@ -38,7 +45,8 @@ class _Configuration():
                 "DB host": self.params.db_host,
                 "DB port": self.params.db_port,
                 "DB master sentinel": self.params.db_sentinel_master_name,
-                "DB sentinel port": self.params.db_sentinel_port
+                "DB sentinel port": self.params.db_sentinel_port,
+                "DB type": self.params.db_type.name,
             }
         )
 
@@ -47,8 +55,21 @@ class _Configuration():
         return self.params
 
     @classmethod
-    def _read_configuration(cls):
+    def _read_configuration(cls, fake_db_backend):
+        backend_type = DbBackendType.REDIS
+        if fake_db_backend:
+            if fake_db_backend.lower() != 'dict':
+                msg = ("Configuration error: "
+                       "SDL instance was initiated with wrong "
+                       "'fake_db_backend' argument value: {}. "
+                       "Value 'dict' is only supported.".
+                       format(fake_db_backend))
+                raise ValueError(msg)
+
+            backend_type = DbBackendType.FAKE_DICT
+
         return _Configuration.Params(db_host=os.getenv('DBAAS_SERVICE_HOST'),
                                      db_port=os.getenv('DBAAS_SERVICE_PORT'),
                                      db_sentinel_port=os.getenv('DBAAS_SERVICE_SENTINEL_PORT'),
-                                     db_sentinel_master_name=os.getenv('DBAAS_MASTER_NAME'))
+                                     db_sentinel_master_name=os.getenv('DBAAS_MASTER_NAME'),
+                                     db_type=backend_type)