Allow the FileDownload class to follow redirects.

kolibri/utils/file_transfer.py

@@ -747,9 +747,15 @@ def _set_headers(self):
         if self._headers_set:
             return
 
-        response = self.session.head(self.source, timeout=self.timeout)
+        response = self.session.head(
+            self.source, timeout=self.timeout, allow_redirects=True
+        )
         response.raise_for_status()
 
+        if response.url != self.source:
+            logger.debug("Redirected from {} to {}".format(self.source, response.url))
+            self.source = response.url
+
         self.compressed = bool(response.headers.get("content-encoding", ""))
 
         self.content_length_header = "content-length" in response.headers

kolibri/utils/tests/test_file_transfer.py

@@ -136,6 +136,7 @@ def mock_get_request(self, url, headers=None, **kwargs):
 
         range_headers = self.get_headers(range_data, start, end)
         mock_response = MagicMock()
+        mock_response.url = url
 
         # Because of the way that requests iterates over the content, we need to
         # keep track of whether the content has been exhausted, so that we can
@@ -166,6 +167,7 @@ def content(other):
     def mock_head_request(self, url, **kwargs):
         mock_response = MagicMock()
         mock_response.headers = self.get_headers(self.content, None, None)
+        mock_response.url = url
         return mock_response
 
     def set_session_mock(self):
@@ -368,6 +370,32 @@ def test_file_download_500_raise(self):
             with self.assertRaises(HTTPError):
                 fd.run()
 
+    def test_file_download_redirect(self):
+        mock_response = MagicMock()
+        mock_response.status_code = 302
+        mock_response.url = "https://example.com/testfile"
+
+        def mock_head_request_redirect(url, **kwargs):
+            mock_response = self.mock_head_request(url, **kwargs)
+            mock_response.status_code = 302
+            mock_response.url = "https://example.com/testfile"
+            return mock_response
+
+        self.mock_session.head.side_effect = mock_head_request_redirect
+
+        with FileDownload(
+            self.source,
+            self.dest,
+            self.checksum,
+            session=self.mock_session,
+            retry_wait=0,
+            full_ranges=self.full_ranges,
+        ) as fd:
+            fd.run()
+
+        self.source = "https://example.com/testfile"
+        self._assert_downloaded_content()
+
     def test_file_download_request_exception(self):
         mock_session = MagicMock()
         mock_session.head.side_effect = RequestException