fix(proxy): fixes GCP inverse proxy url priority. Fixes #4284 (#4702)

* fix: fixes proxy url priority

uses proxy url that is closest to the given zone

Fixes #4284

* style: formatting proxy with yapf

using .style.yapf provided in the repo

proxy/get_proxy_url.py

@@ -12,7 +12,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
 """CLI tool that returns URL of the proxy for particular zone and version."""
 import argparse
 import functools
@@ -22,12 +21,13 @@
 import requests
 
 try:
-  unicode
+    unicode
 except NameError:
-  unicode = str
+    unicode = str
+
 
 def urls_for_zone(zone, location_to_urls_map):
-  """Returns list of potential proxy URLs for a given zone.
+    """Returns list of potential proxy URLs for a given zone.
 
   Returns:
     List of possible URLs, in order of proximity.
@@ -41,71 +41,79 @@ def urls_for_zone(zone, location_to_urls_map):
         ...
       }
   """
-  zone_match = re.match("((([a-z]+)-[a-z]+)\d+)-[a-z]", zone)
-  if not zone_match:
-    raise ValueError("Incorrect zone specified: {}".format(zone))
+    zone_match = re.match("((([a-z]+)-[a-z]+)\d+)-[a-z]", zone)
+    if not zone_match:
+        raise ValueError("Incorrect zone specified: {}".format(zone))
 
-  # e.g. zone = us-west1-b
-  region = zone_match.group(1)         # us-west1
-  approx_region = zone_match.group(2)  # us-west
-  country = zone_match.group(3)        # us
+    # e.g. zone = us-west1-b
+    region = zone_match.group(1)  # us-west1
+    approx_region = zone_match.group(2)  # us-west
+    country = zone_match.group(3)  # us
 
-  urls = []
-  if region in location_to_urls_map:
-    urls.extend(location_to_urls_map[region])
+    urls = []
+    if region in location_to_urls_map:
+        urls.extend([
+            url for url in location_to_urls_map[region] if url not in urls
+        ])
 
-  region_regex = re.compile("([a-z]+-[a-z]+)\d+")
-  for location in location_to_urls_map:
-    region_match = region_regex.match(location)
-    if region_match and region_match.group(1) == approx_region:
-      urls.extend(location_to_urls_map[location])
+    region_regex = re.compile("([a-z]+-[a-z]+)\d+")
+    for location in location_to_urls_map:
+        region_match = region_regex.match(location)
+        if region_match and region_match.group(1) == approx_region:
+            urls.extend([
+                url for url in location_to_urls_map[location] if url not in urls
+            ])
 
-  if country in location_to_urls_map:
-    urls.extend(location_to_urls_map[country])
+    if country in location_to_urls_map:
+        urls.extend([
+            url for url in location_to_urls_map[country] if url not in urls
+        ])
 
-  return set(urls)
+    return urls
 
 
 def main():
-  unicode_type = functools.partial(unicode, encoding="utf8")
-  parser = argparse.ArgumentParser(
-      description="Get proxy URL")
-  parser.add_argument("--config-file-path", required=True, type=unicode_type)
-  parser.add_argument("--location", required=True, type=unicode_type)
-  parser.add_argument("--version", required=True, type=unicode_type)
-
-  args = parser.parse_args()
-  with open(args.config_file_path, "r") as config_file:
-    data = json.loads(config_file.read())
-
-  agent_containers_config = data["agent-docker-containers"]
-  version = args.version
-  if version not in agent_containers_config:
-    version = "latest"
-  if version not in agent_containers_config:
-    raise ValueError("Version latest not found in the config file.")
-  container_config = agent_containers_config[version]
-  regional_urls = container_config["proxy-urls"]
-
-  location = args.location
-  urls = urls_for_zone(location, regional_urls)
-  if not urls:
-    raise ValueError("No valid URLs found for zone: {}".format(location))
-
-  for url in urls:
-    try:
-      status_code = requests.head(url).status_code
-    except requests.ConnectionError:
-      pass
-    expected_codes = frozenset([307])
-    # 307 - Temporary Redirect, Proxy server sends this if VM has access rights.
-    if status_code in expected_codes:
-      logging.debug("Status code from the url %s", status_code)
-      print(url)
-      exit(0)
-    logging.debug("Incorrect status_code from the server: %s. Expected: %s",
-                  status_code, expected_codes)
-  raise ValueError("No working URL found")
+    unicode_type = functools.partial(unicode, encoding="utf8")
+    parser = argparse.ArgumentParser(description="Get proxy URL")
+    parser.add_argument("--config-file-path", required=True, type=unicode_type)
+    parser.add_argument("--location", required=True, type=unicode_type)
+    parser.add_argument("--version", required=True, type=unicode_type)
+
+    args = parser.parse_args()
+    with open(args.config_file_path, "r") as config_file:
+        data = json.loads(config_file.read())
+
+    agent_containers_config = data["agent-docker-containers"]
+    version = args.version
+    if version not in agent_containers_config:
+        version = "latest"
+    if version not in agent_containers_config:
+        raise ValueError("Version latest not found in the config file.")
+    container_config = agent_containers_config[version]
+    regional_urls = container_config["proxy-urls"]
+
+    location = args.location
+    urls = urls_for_zone(location, regional_urls)
+    if not urls:
+        raise ValueError("No valid URLs found for zone: {}".format(location))
+
+    for url in urls:
+        try:
+            status_code = requests.head(url).status_code
+        except requests.ConnectionError:
+            pass
+        expected_codes = frozenset([307])
+        # 307 - Temporary Redirect, Proxy server sends this if VM has access rights.
+        if status_code in expected_codes:
+            logging.debug("Status code from the url %s", status_code)
+            print(url)
+            exit(0)
+        logging.debug(
+            "Incorrect status_code from the server: %s. Expected: %s",
+            status_code, expected_codes
+        )
+    raise ValueError("No working URL found")
+
 
 if __name__ == '__main__':
-  main()
+    main()

proxy/get_proxy_url_test.py

@@ -22,24 +22,36 @@
     {
       "us": ["https://datalab-us-west1.cloud.google.com"],
       "us-west1": ["https://datalab-us-west1.cloud.google.com"],
+      "us-west2": ["https://datalab-us-west2.cloud.google.com"],
       "us-east1": ["https://datalab-us-east1.cloud.google.com"]
     }
     """
 
+
 class TestUrlsForZone(unittest.TestCase):
 
-  def test_get_urls(self):
-    self.assertEqual(
-        set(["https://datalab-us-east1.cloud.google.com","https://datalab-us-west1.cloud.google.com"]),
-        urls_for_zone("us-east1-a",json.loads(url_map_json)))
+    def test_get_urls(self):
+        self.assertEqual([
+            "https://datalab-us-east1.cloud.google.com",
+            "https://datalab-us-west1.cloud.google.com"
+        ], urls_for_zone("us-east1-a", json.loads(url_map_json)))
+
+    def test_get_urls_no_match(self):
+        self.assertEqual([],
+                         urls_for_zone(
+                             "euro-west1-a", json.loads(url_map_json)
+                         ))
 
+    def test_get_urls_incorrect_format(self):
+        with self.assertRaises(ValueError):
+            urls_for_zone("weird-format-a", json.loads(url_map_json))
 
-  def test_get_urls_no_match(self):
-    self.assertEqual(set([]), urls_for_zone("euro-west1-a",json.loads(url_map_json)))
+    def test_get_urls_priority(self):
+        self.assertEqual([
+            "https://datalab-us-west1.cloud.google.com",
+            "https://datalab-us-west2.cloud.google.com"
+        ], urls_for_zone("us-west1-a", json.loads(url_map_json)))
 
-  def test_get_urls_incorrect_format(self):
-    with self.assertRaises(ValueError):
-      urls_for_zone("weird-format-a",json.loads(url_map_json))
 
 if __name__ == '__main__':
-  unittest.main()
+    unittest.main()