Add networking settings to client config

Extend the UpdaterConfig class with the settings
needed for RequestsFetcher.

Signed-off-by: Teodora Sechkova <[email protected]>

Author: sechkova

tuf/ngclient/_internal/requests_fetcher.py

@@ -14,7 +14,7 @@
 import urllib3.exceptions
 
 import tuf
-from tuf import exceptions, settings
+from tuf import exceptions
 from tuf.ngclient.fetcher import FetcherInterface
 
 # Globals
@@ -30,7 +30,7 @@ class RequestsFetcher(FetcherInterface):
             session per scheme+hostname combination.
     """
 
-    def __init__(self):
+    def __init__(self, config: "UpdaterConfig"):
         # http://docs.python-requests.org/en/master/user/advanced/#session-objects:
         #
         # "The Session object allows you to persist certain parameters across
@@ -46,6 +46,7 @@ def __init__(self):
         # hosts-scheme combinations to minimize subtle security issues.
         # Some cookies may not be HTTP-safe.
         self._sessions = {}
+        self.config = config
 
     def fetch(self, url, required_length):
         """Fetches the contents of HTTP/HTTPS url from a remote server.
@@ -76,7 +77,7 @@ def fetch(self, url, required_length):
         #  - connect timeout (max delay before first byte is received)
         #  - read (gap) timeout (max delay between bytes received)
         response = session.get(
-            url, stream=True, timeout=settings.SOCKET_TIMEOUT
+            url, stream=True, timeout=self.config.SOCKET_TIMEOUT
         )
         # Check response status.
         try:
@@ -99,11 +100,11 @@ def chunks():
                     # large file in one shot. Before beginning the round, sleep
                     # (if set) for a short amount of time so that the CPU is not
                     # hogged in the while loop.
-                    if settings.SLEEP_BEFORE_ROUND:
-                        time.sleep(settings.SLEEP_BEFORE_ROUND)
+                    if self.config.SLEEP_BEFORE_ROUND:
+                        time.sleep(self.config.SLEEP_BEFORE_ROUND)
 
                     read_amount = min(
-                        settings.CHUNK_SIZE,
+                        self.config.CHUNK_SIZE,
                         required_length - bytes_received,
                     )
 

tuf/ngclient/config.py

@@ -1,17 +1,26 @@
 # Copyright 2021, New York University and the TUF contributors
 # SPDX-License-Identifier: MIT OR Apache-2.0
 
-"""Configuration options for Updater class
+"""Client configuration options
 """
 
 from dataclasses import dataclass
+from typing import Optional
 
 
 @dataclass
 class UpdaterConfig:
+    """Client workflow configuration"""
+
+    # Updater settings
     MAX_ROOT_ROTATIONS: int = 32
     MAX_DELEGATIONS: int = 32
     DEFAULT_ROOT_MAX_LENGTH: int = 512000  # bytes
     DEFAULT_TIMESTAMP_MAX_LENGTH: int = 16384  # bytes
     DEFAULT_SNAPSHOT_MAX_LENGTH: int = 2000000  # bytes
     DEFAULT_TARGETS_MAX_LENGTH: int = 5000000  # bytes
+
+    # RequestsFetcher settings
+    SOCKET_TIMEOUT: int = 4  # seconds
+    CHUNK_SIZE: int = 400000  # bytes
+    SLEEP_BEFORE_ROUND: Optional[int] = None

tuf/ngclient/updater.py

@@ -65,16 +65,16 @@ def __init__(
         data = self._load_local_metadata("root")
         self._trusted_set = trusted_metadata_set.TrustedMetadataSet(data)
 
-        if fetcher is None:
-            self._fetcher = requests_fetcher.RequestsFetcher()
-        else:
-            self._fetcher = fetcher
-
         if config is None:
             self.config = UpdaterConfig()
         else:
             self.config = config
 
+        if fetcher is None:
+            self._fetcher = requests_fetcher.RequestsFetcher(self.config)
+        else:
+            self._fetcher = fetcher
+
     def refresh(self) -> None:
         """
         This method downloads, verifies, and loads metadata for the top-level