python: move VMIHandler into it's own package

python/microvmi/volatility/__init__.py

@@ -0,0 +1,8 @@
+"""
+This package regroups the volatility plugins developed on top of the Microvmi package
+
+It is intended to be used as a volatility3 plugins directory:
+
+Example:
+    vol.py -p /path/to/microvmi/volatility windows.pslist.PsList
+"""

python/microvmi/handler.py → python/microvmi/volatility/vmi_handler.py

@@ -1,5 +1,5 @@
 import logging
-from typing import Any, List, Optional, Tuple, Type
+from typing import Any, List, Optional, Tuple
 from urllib.parse import parse_qs, urlparse
 from urllib.request import BaseHandler, Request
 
@@ -8,22 +8,23 @@
 # to be used by volatility, the VMIHandler should inherit from VolatilityHandler
 # in order to be non cacheable
 # if we find volatility, use VolatilityHandler, otherwise use the BaseHandler from stdlib
-HANDLER_BASE_CLASS: Type[BaseHandler] = BaseHandler
 try:
-    from volatility3.framework.layers.handler import VolatilityHandler
-
-    HANDLER_BASE_CLASS = VolatilityHandler
+    from volatility3.framework.layers.resources import VolatilityHandler
 except ImportError:
-    pass
+    # define dummy class
+    # mypy checking: ignore name already defined
+    class VolatilityHandler(BaseHandler):  # type: ignore
+        pass
+
 
 micro: Optional[Microvmi] = None
 
 
 class MicrovmiHandlerError(Exception):
     pass
 
-# Note: mypy: dynamic base classes are not handled
-class VMIHandler(HANDLER_BASE_CLASS):   # type: ignore
+
+class VMIHandler(VolatilityHandler):
     """
     Handles the Virtual Machine Introspection URL scheme based on libmicrovmi
 

python/tests/test_handler.py

@@ -1,6 +1,6 @@
 import pytest
 from microvmi import DriverType
-from microvmi.handler import MicrovmiHandlerError, url_to_driver_parameters
+from microvmi.volatility.vmi_handler import MicrovmiHandlerError, url_to_driver_parameters
 
 
 def test_valid_scheme():