fix: usr: Bug fix for access denied error while downloading file. Pul…

…l Request #190.

SDK-191: Aws throws Access denied errors in situations where the versioning on
s3 files is enabled and an attempt to download the file is done by specifying the
version(default beahvior by aws boto2). This is seen in boto2 and the workaround is to
retry downloading again without specifying the version of the file.

qds_sdk/commands.py

@@ -1342,7 +1342,18 @@ def _is_complete_data_available(bucket_paths, num_result_dir):
             raise Exception("Results file not available on s3 yet. This can be because of s3 eventual consistency issues.")
         log.info("Downloading file from %s" % s3_path)
         if delim is None:
-            key_instance.get_contents_to_file(fp)  # cb=_callback
+            try:
+                key_instance.get_contents_to_file(fp)  # cb=_callback
+            except boto.exception.S3ResponseError as e:
+                if (e.status == 403):
+                    # SDK-191, boto gives an error while fetching the objects using versions which happens by default
+                    # in the get_contents_to_file() api. So attempt one without specifying version.
+                    log.warn("Access denied while fetching the s3 object. Retrying without specifying the version....")
+                    key_instance.open()
+                    fp.write(key_instance.read())
+                    key_instance.close()
+                else:
+                    raise
         else:
             # Get contents as string. Replace parameters and write to file.
             _read_iteratively(key_instance, fp, delim=delim)