move common code into server, update tests and makefile (#2425)

* move common code into server, update tests and makefile

remove backend directory, refactor

update smoke tests

server/common/config/external_config.py

@@ -0,0 +1,44 @@
+import os
+
+from server.common.config.base_config import BaseConfig
+from server.common.errors import ConfigurationError
+from server.common.utils.type_conversion_utils import convert_string_to_value
+
+
+class ExternalConfig(BaseConfig):
+    """Manages the config attribute associated with external configuration sources, such as
+    environment variables."""
+
+    def __init__(self, app_config, default_config):
+        super().__init__(app_config, default_config)
+        try:
+            self.environment = default_config["environment"]
+
+        except KeyError as e:
+            raise ConfigurationError(f"Unexpected config: {str(e)}")
+
+    def complete_config(self, context):
+        self.handle_environment(context)
+
+    def handle_environment(self, context):
+        """For each environment variable defined, get the value (if it is set),
+        and set the specified config parameter"""
+        self.validate_correct_type_of_configuration_attribute("environment", list)
+        for envdict in self.environment:
+            name = envdict.get("name")
+            if name is None:
+                raise ConfigurationError("environment: 'name' is missing")
+            required = envdict.get("required", False)
+            if type(required) != bool:
+                raise ConfigurationError("environment: 'required' must be a bool")
+            path = envdict.get("path")
+            if path is None:
+                raise ConfigurationError("environment: 'path' is missing")
+
+            value = os.environ.get(name)
+            if value is None:
+                if required:
+                    raise ConfigurationError(f"required environment variable '{name}' not set")
+            else:
+                value = convert_string_to_value(value)
+                self.app_config.update_single_config_from_path_and_value(path, value)