IBP: Fix socket.timeout catching

Recent version of python-requests doesn't catch socket.timeout()
This patch resolves the issue by explicit adding socket.timeout to
the list of expected exceptions to be caught.

Change-Id: Ifcadf9efbec633175bb1bd31cf7f58732c2e78c4
Closes-Bug: #1458526

fuel_agent/tests/test_utils.py

@@ -18,6 +18,7 @@ import testtools
 import mock
 from oslo.config import cfg
 import requests
+import socket
 import stevedore
 import urllib3
 
@@ -140,6 +141,7 @@ class ExecuteTestCase(testtools.TestCase):
                                 requests.exceptions.ConnectionError(),
                                 requests.exceptions.Timeout(),
                                 requests.exceptions.TooManyRedirects(),
+                                socket.timeout(),
                                 mock_ok]
         req_obj = utils.init_http_request('fake_url')
         self.assertEqual(mock_ok, req_obj)

fuel_agent/utils/utils.py

@@ -18,6 +18,7 @@ import math
 import os
 import re
 import shlex
+import socket
 import subprocess
 import time
 
@@ -203,7 +204,8 @@ def init_http_request(url, byte_range=0):
                     url, stream=True,
                     timeout=CONF.http_request_timeout,
                     headers={'Range': 'bytes=%s-' % byte_range})
-            except (urllib3.exceptions.DecodeError,
+            except (socket.timeout,
+                    urllib3.exceptions.DecodeError,
                     urllib3.exceptions.ProxyError,
                     requests.exceptions.ConnectionError,
                     requests.exceptions.Timeout,