Remove symlink if exists

On sync, if the symlink already exists, an exception would
be thrown.  This change removes the file if it already
exists.

Bug 1132

Change-Id: I151a96adcac5d7cd51b84c2770f498a78d7d68be
Signed-off-by: beierlm <mark.beierl@canonical.com>
(cherry picked from commit 6d72d5cfb6f75c62402d493fdc2d81797cd48081)
(cherry picked from commit ff2e826ee2ead832eff974e331aed3994e9b06f9)

diff --git a/osm_common/fsmongo.py b/osm_common/fsmongo.py
index 6a96d44..af52ee5 100644 (file)
--- a/osm_common/fsmongo.py
+++ b/osm_common/fsmongo.py
@@ -16,13 +16,16 @@
 # contact: eduardo.sousa@canonical.com
 ##
 
+import errno
+from http import HTTPStatus
 from io import BytesIO, StringIO
-from pymongo import MongoClient
-from gridfs import GridFSBucket, errors
 import logging
-from http import HTTPStatus
 import os
+
+from gridfs import GridFSBucket, errors
 from osm_common.fsbase import FsBase, FsException
+from pymongo import MongoClient
+
 
 __author__ = "Eduardo Sousa <eduardo.sousa@canonical.com>"
 
@@ -211,6 +214,13 @@ class FsMongo(FsBase):
                     self.fs.download_to_stream(writing_file._id, b)
                     b.seek(0)
                     link = b.read().decode("utf-8")
+
+                try:
+                    os.remove(file_path)
+                except OSError as e:
+                    if e.errno != errno.ENOENT:
+                        # This is probably permission denied or worse
+                        raise
                 os.symlink(link, file_path)
             else:
                 with open(file_path, 'wb+') as file_stream:
@@ -313,7 +323,7 @@ class FsMongo(FsBase):
 
             if requested_file.metadata["type"] == mode:
                 return True
-            
+
             if requested_file.metadata["type"] == "sym" and mode == "file":
                 return True
 
@@ -448,7 +458,7 @@ class FsMongo(FsBase):
                 else:
                     self.fs.delete(requested_file._id)
             if not found and not ignore_non_exist:
-                raise FsException("File {} does not exist".format(storage), http_code=HTTPStatus.NOT_FOUND)    
+                raise FsException("File {} does not exist".format(storage), http_code=HTTPStatus.NOT_FOUND)
         except IOError as e:
             raise FsException("File {} cannot be deleted: {}".format(f, e), http_code=HTTPStatus.INTERNAL_SERVER_ERROR)