Revize c073a0fc

Re #8569 Added support for handling configuration files

app.py

@@ -66 +66 @@
     """
     global certificate_controller
 
-    injector = Injector([configuration.configure_default, ConnectionProvider])
+    injector = Injector([configuration.configure_env_variable, ConnectionProvider])
     certificate_controller = injector.get(CertController)
 
     # There's a little dependency on the CryptoService, which is not a pretty thing from

src/config/configuration.py

@@ +1 @@
+import os
+
+import configparser
 from injector import singleton
 
+from src.constants import DEFAULT_CONNECTION_STRING
+
+DATABASE_SECTION = "Database"
+DATABASE_CONNECTION_STRING = "ConnectionString"
 
 class Configuration:
+    """
+    Configuration class servers for injecting current application
+    configuration all over the application
+    """
+
+    def __init__(self):
+        """
+        Constructor
+        It must initialize all variables to their default values
+        """
+        self.connection_string = DEFAULT_CONNECTION_STRING
+
 
-    def __init__(self, connection_string):
-        self.connection_string = connection_string
+def configure_env_variable(binder):
+    """
+    Load configuration file stored in X509_CONFIG environment variable.
+    If the file is not specified, use the default configuration
+    :param binder: injector configuration binder instance
+    :return: N/A
+    """
+    # TODO log which configuration is going to be used
+    config_file = os.environ.get("X509_CONFIG")
+    app_configuration = Configuration()
+    # if configuration file is not specified use the default configuration
+    if config_file is not None:
+        config = configparser.ConfigParser()
+        config.read(config_file)
 
+        if config[DATABASE_SECTION] is not None:
+            database_config = config[DATABASE_SECTION]
+            app_configuration.connection_string = database_config.get(DATABASE_CONNECTION_STRING,
+                                                                      DEFAULT_CONNECTION_STRING)
 
-def configure_default(binder):
-    configuration = Configuration("db/database_sqlite.db")
-    binder.bind(Configuration, to=configuration, scope=singleton)
+    binder.bind(Configuration, to=app_configuration, scope=singleton)

src/constants.py

@@ -42 +42 @@
 # DB column names of PrivateKey table
 COL_CERTIFICATE_ID = "certificate_id"
 COL_USAGE_TYPE_ID = "usage_type_id"
+
+# configuration default
+DEFAULT_CONNECTION_STRING = "db/database_sqlite.db"