Improve config.json handling, making single_location optional but bypasses the stacker automagic.

volatility/cli/__init__.py

@@ -98,6 +98,12 @@ class CommandLine(object):
         plugin = plugin_list[args.plugin]
         plugin_config_path = interfaces.configuration.path_join('plugins', plugin.__name__)
 
+        # UI fills in the config, here we load it from the config file and do it before we process the CL parameters
+        if args.config:
+            with open(args.config, "r") as f:
+                json_val = json.load(f)
+                ctx.config.splice(plugin_config_path, HierarchicalDict(json_val))
+
         # Populate the context config based on the returned args
         # We have already determined these elements must be descended from ConfigurableInterface
         vargs = vars(args)
@@ -113,12 +119,6 @@ class CommandLine(object):
                     extended_path = interfaces.configuration.path_join(config_path, requirement.name)
                     ctx.config[extended_path] = value
 
-        # UI fills in the config:
-        if args.config:
-            with open(args.config, "r") as f:
-                json_val = json.load(f)
-                ctx.config.splice(plugin_config_path, HierarchicalDict(json_val))
-
         ###
         # BACK TO THE FRAMEWORK
         ###
@@ -134,8 +134,10 @@ class CommandLine(object):
 
         constructed = plugin(ctx, plugin_config_path)
 
-        with open("config.json", "w") as f:
-            json.dump(dict(constructed.build_configuration()), f, sort_keys = True, indent = 2)
+        if args.verbosity >= 2:
+            vollog.debug("Writing out configuration data to config.json")
+            with open("config.json", "w") as f:
+                json.dump(dict(constructed.build_configuration()), f, sort_keys = True, indent = 2)
 
         # Construct and run the plugin
         QuickTextRenderer().render(constructed.run())

volatility/framework/automagic/stacker.py

@@ -11,8 +11,7 @@ import logging
 from urllib import parse
 
 import volatility
-from volatility.framework import configuration
-from volatility.framework import interfaces
+from volatility.framework import configuration, interfaces
 from volatility.framework.automagic import construct_layers
 from volatility.framework.configuration import requirements
 from volatility.framework.layers import physical
@@ -48,6 +47,9 @@ class LayerStacker(interfaces.automagic.AutomagicInterface):
             vollog.info("Unable to run LayerStacker, unsatisfied requirement: {}".format(unsatisfied))
             return unsatisfied
         location = self.config["single_location"]
+        if not location:
+            vollog.info("Unable to run LayerStacker, single_location parameter not provided")
+            return []
         self._check_type(location, str)
         self._check_type(requirement, interfaces.configuration.RequirementInterface)
         location = parse.urlparse(location)
@@ -135,4 +137,4 @@ class LayerStacker(interfaces.automagic.AutomagicInterface):
         # This is not optional for the stacker to run, so optional must be marked as False
         return [requirements.StringRequirement("single_location",
                                                description = "Specifies a base location on which to stack",
-                                               optional = False)]
+                                               optional = True)]