Add the ability to blacklist v2 for specific versions

util/registry/dockerver.py

@@ -0,0 +1,27 @@
+import re
+
+from semantic_version import Version
+
+_USER_AGENT_SEARCH_REGEX = re.compile(r'docker\/([0-9]+(?:\.[0-9]+){1,2})')
+_EXACT_1_5_USER_AGENT = re.compile(r'^Go 1\.1 package http$')
+_ONE_FIVE_ZERO = '1.5.0'
+
+def docker_version(user_agent_string):
+  """ Extract the Docker version from the user agent, taking special care to
+      handle the case of a 1.5 client requesting an auth token, which sends
+      a broken user agent. If we can not positively identify a version, return
+      None.
+      """
+
+  # First search for a well defined semver portion in the UA header.
+  found_semver = _USER_AGENT_SEARCH_REGEX.search(user_agent_string)
+  if found_semver:
+    return Version(found_semver.group(1), partial=True)
+
+  # Check if we received the very specific header which represents a 1.5 request
+  # to the auth endpoints.
+  elif _EXACT_1_5_USER_AGENT.match(user_agent_string):
+    return Version(_ONE_FIVE_ZERO)
+
+  else:
+    return None