Improve merging of config files

When loading toml config files, new files would completely
overwrite the values associated with root keys in the old files.
This change allows for a cleaner merge when some values overwrite
and some just extend.

Include new python module mergedeep (MIT license)

Signed-off-by: Mic Bowman <[email protected]>

Author: cmickeyb

build/Makefile

@@ -100,6 +100,7 @@ $(PYTHON_DIR) :
 	. $(abspath $(DSTDIR)/bin/activate) && pip install --upgrade websocket-client
 	. $(abspath $(DSTDIR)/bin/activate) && pip install --upgrade msgpack
 	. $(abspath $(DSTDIR)/bin/activate) && pip install --upgrade ccf==1.0.19
+	. $(abspath $(DSTDIR)/bin/activate) && pip install --upgrade mergedeep
 
 $(DSTDIR) :
 	@echo CREATE INSTALLATION DIRECTORY $(DSTDIR)

python/pdo/common/config.py

@@ -20,6 +20,7 @@
 before logging is enabled.
 """
 
+import mergedeep
 import os
 import sys
 import warnings
@@ -89,7 +90,7 @@ def parse_configuration_files(cfiles, search_path, variable_map = None) :
 
     for filename in files_found :
         try :
-            config.update(parse_configuration_file(filename, variable_map))
+            mergedeep.merge(config, parse_configuration_file(filename, variable_map))
         except IOError as detail :
             raise ConfigurationException(filename, "IO error; {0}".format(str(detail)))
         except ValueError as detail :