Merge pull request #1342 from codeswhite/patch-network-retry

Implemented connectivity check (Fixed #1038)

testUpdateHostsFile.py

@@ -1627,14 +1627,14 @@ class GetFileByUrl(BaseStdout):
         url = b"www.google.com"
 
         expected = "www.google.com"
-        actual = get_file_by_url(url)
+        actual = get_file_by_url(url, delay=0)
 
         self.assertEqual(actual, expected)
 
     @mock.patch("updateHostsFile.urlopen", side_effect=mock_url_open_fail)
     def test_read_url_fail(self, _):
         url = b"www.google.com"
-        self.assertIsNone(get_file_by_url(url))
+        self.assertIsNone(get_file_by_url(url, delay=0))
 
         expected = "Problem getting file:"
         output = sys.stdout.getvalue()
@@ -1644,7 +1644,7 @@ class GetFileByUrl(BaseStdout):
     @mock.patch("updateHostsFile.urlopen", side_effect=mock_url_open_read_fail)
     def test_read_url_read_fail(self, _):
         url = b"www.google.com"
-        self.assertIsNone(get_file_by_url(url))
+        self.assertIsNone(get_file_by_url(url, delay=0))
 
         expected = "Problem getting file:"
         output = sys.stdout.getvalue()
@@ -1654,7 +1654,7 @@ class GetFileByUrl(BaseStdout):
     @mock.patch("updateHostsFile.urlopen", side_effect=mock_url_open_decode_fail)
     def test_read_url_decode_fail(self, _):
         url = b"www.google.com"
-        self.assertIsNone(get_file_by_url(url))
+        self.assertIsNone(get_file_by_url(url, delay=0))
 
         expected = "Problem getting file:"
         output = sys.stdout.getvalue()

updateHostsFile.py

@@ -1469,7 +1469,7 @@ def maybe_copy_example_file(file_path):
             shutil.copyfile(example_file_path, file_path)
 
 
-def get_file_by_url(url):
+def get_file_by_url(url, retries=3, delay=10):
     """
     Get a file data located at a particular URL.
 
@@ -1490,12 +1490,19 @@ def get_file_by_url(url):
         format we have to encode or decode data before parsing it to UTF-8.
     """
 
-    try:
-        f = urlopen(url)
-        soup = BeautifulSoup(f.read(), "lxml").get_text()
-        return "\n".join(list(map(domain_to_idna, soup.split("\n"))))
-    except Exception:
-        print("Problem getting file: ", url)
+    while retries:
+        try:
+            with urlopen(url) as f:
+                soup = BeautifulSoup(f.read(), "lxml").get_text()
+                return "\n".join(list(map(domain_to_idna, soup.split("\n"))))
+        except Exception as e:
+            if 'failure in name resolution' in str(e):
+                print('No internet connection! Retrying in {} seconds'.format(delay))
+                time.sleep(delay)
+                retries -= 1
+                continue
+            break
+    print("Problem getting file: ", url)
 
 
 def write_data(f, data):