Basic logging for package-installs-squash

Some basic info logging and debugging for package-installs-squash.

Change-Id: If7c227cf0a53b71d334b5f5a6075120f2a7bf3a7

diskimage_builder/elements/package-installs/bin/package-installs-squash

@@ -18,10 +18,15 @@ import argparse
 import collections
 import functools
 import json
+import logging
 import os
 import sys
 import yaml
 
+from diskimage_builder import logging_config
+
+logger = logging.getLogger(__name__)
+
 
 def get_element_installtype(element_name):
     default = os.environ.get("DIB_DEFAULT_INSTALLTYPE", "source")
@@ -97,6 +102,8 @@ def main():
     parser.add_argument('outfile', help="Location of the output file")
     args = parser.parse_args()
 
+    logging_config.setup()
+
     # Replicate the logic of finding the first element, because we can't
     # operate on the post-copied hooks dir, since we lose element context
     element_dirs = list()
@@ -106,6 +113,8 @@ def main():
             if os.path.exists(potential_path):
                 element_dirs.append((elements_dir, element_name))
 
+    logger.debug("element_dirs -> %s" % element_dirs)
+
     # Collect the merge of all of the existing install files in the elements
     # that are the first on the ELEMENT_PATH
     final_dict = collections.defaultdict(
@@ -116,8 +125,11 @@ def main():
                 elements_dir, element_name, "package-installs.%s" % file_type)
             if not os.path.exists(target_file):
                 continue
+            logger.info("Squashing install file: %s" % target_file)
             final_dict = collect_data(final_dict, target_file, element_name)
 
+    logger.debug("final_dict -> %s" % final_dict)
+
     # Write the resulting file
     with open(args.outfile, 'w') as outfile:
         json.dump(