@@ -154,7 +154,7 @@ def buildSourcesList(yamlDir, blackListPkgs, logger, singleFile=True):

             sourceName = listSourceNames[0]

             sha1 = SPECS.getData().getSHA1(package, sourceName)

             if sha1 is not None:

-                PullSources.get(sourceName, sha1, yamlSourceDir,

+                PullSources.get(package, sourceName, sha1, yamlSourceDir,

                                 constants.pullsourcesConfig, logger)

         if not singleFile:

@@ -450,8 +450,8 @@ class PackageUtils(object):

         # Fetch/verify sources if sha1 not None.

         sha1 = SPECS.getData().getSHA1(package, source, index)

         if sha1 is not None:

-            PullSources.get(source, sha1, constants.sourcePath, constants.pullsourcesConfig,

-                            self.logger)

+            PullSources.get(package, source, sha1, constants.sourcePath,

+                            constants.pullsourcesConfig, self.logger)

         sourcePath = cmdUtils.findFile(source, constants.sourcePath)

         if not sourcePath:

@@ -22,7 +22,7 @@ def getFileHash(filepath):

         f.close()

     return sha1.hexdigest()

-def get(source, sha1, sourcesPath, configs, logger):

+def get(package, source, sha1, sourcesPath, configs, logger):

     cmdUtils = CommandUtils()

     sourcePath = cmdUtils.findFile(source, sourcesPath)

     if sourcePath is not None and len(sourcePath) > 0:

@@ -40,7 +40,7 @@ def get(source, sha1, sourcesPath, configs, logger):

         p = pullSources(config, logger)

         package_path = os.path.join(sourcesPath, source)

         try:

-            p.downloadFileHelper(source, package_path, sha1)

+            p.downloadFileHelper(package, source, package_path, sha1)

             return

         except Exception as e:

             logger.exception(e)

@@ -63,13 +63,21 @@ class pullSources:

         with open(conf_file) as jsonFile:

             self._config = json.load(jsonFile)

-    def downloadFile(self, filename, file_path):

+    def downloadFile(self, package, filename, file_path):

         #form url: https://dl.bintray.com/vmware/photon_sources/1.0/<filename>.

         url = '%s/%s' % (self._config['baseurl'], filename)

         self.logger.info("Downloading: " + url)

-        with open(file_path, 'wb') as handle:

+        # We need to provide atomicity for file downloads. That is,

+        # the file should be visible in its canonical location only

+        # when the download is complete. To achieve that, first

+        # download to a temporary location (on the same filesystem)

+        # and then rename it to the final destination filename.

+

+        temp_file_path = file_path + "-" + package

+

+        with open(temp_file_path, 'wb') as handle:

             response = requests.get(url, auth=self._auth, stream=True)

             if not response.ok:

@@ -82,9 +90,15 @@ class pullSources:

                 handle.write(block)

             handle.flush()

             response.close()

+

+        if os.path.exists(file_path):

+            os.remove(temp_file_path)

+        else:

+            os.rename(temp_file_path, file_path)

+

         return file_path

-    def downloadFileHelper(self, package_name, package_path, package_sha1=None):

-        self.downloadFile(package_name, package_path)

-        if package_sha1 != getFileHash(package_path):

-            raise Exception('Invalid sha1 for package %s' % package_name)

+    def downloadFileHelper(self, package, filename, file_path, package_sha1=None):

+        self.downloadFile(package, filename, file_path)

+        if package_sha1 != getFileHash(file_path):

+            raise Exception('Invalid sha1 for package %s file %s' % package, filename)