Merge pull request #2891 from coreos-inc/joseph.schorr/QS-38/refactor-storage

Small storage refactoring

storage/__init__.py

@@ -4,6 +4,7 @@ from storage.fakestorage import FakeStorage
 from storage.distributedstorage import DistributedStorage
 from storage.swift import SwiftStorage
 from storage.downloadproxy import DownloadProxy
+from util.ipresolver import NoopIPResolver
 
 STORAGE_DRIVER_CLASSES = {
   'LocalStorage': LocalStorage,
@@ -15,13 +16,15 @@ STORAGE_DRIVER_CLASSES = {
 }
 
 
-def get_storage_driver(location, metric_queue, chunk_cleanup_queue, config_provider, ip_resolver, storage_params):
+def get_storage_driver(location, metric_queue, chunk_cleanup_queue, config_provider, ip_resolver,
+                       storage_params):
   """ Returns a storage driver class for the given storage configuration
       (a pair of string name and a dict of parameters). """
   driver = storage_params[0]
   parameters = storage_params[1]
   driver_class = STORAGE_DRIVER_CLASSES.get(driver, FakeStorage)
-  context = StorageContext(location, metric_queue, chunk_cleanup_queue, config_provider, ip_resolver)
+  context = StorageContext(location, metric_queue, chunk_cleanup_queue, config_provider,
+                           ip_resolver)
   return driver_class(context, **parameters)
 
 
@@ -31,7 +34,7 @@ class StorageContext(object):
     self.metric_queue = metric_queue
     self.chunk_cleanup_queue = chunk_cleanup_queue
     self.config_provider = config_provider
-    self.ip_resolver = ip_resolver
+    self.ip_resolver = ip_resolver or NoopIPResolver()
 
 
 class Storage(object):
@@ -44,7 +47,8 @@ class Storage(object):
     else:
       self.state = None
 
-  def init_app(self, app, metric_queue, chunk_cleanup_queue, instance_keys, config_provider, ip_resolver):
+  def init_app(self, app, metric_queue, chunk_cleanup_queue, instance_keys, config_provider,
+               ip_resolver):
     storages = {}
     for location, storage_params in app.config.get('DISTRIBUTED_STORAGE_CONFIG').items():
       storages[location] = get_storage_driver(location, metric_queue, chunk_cleanup_queue,

storage/cloud.py

@@ -577,12 +577,13 @@ class RadosGWStorage(_CloudStorage):
                                          storage_path, bucket_name, access_key, secret_key)
 
   # TODO remove when radosgw supports cors: http://tracker.ceph.com/issues/8718#change-38624
-  def get_direct_download_url(self, path, request_ip=None, expires_in=60, requires_cors=False, head=False):
+  def get_direct_download_url(self, path, request_ip=None, expires_in=60, requires_cors=False,
+                              head=False):
     if requires_cors:
       return None
 
-    return super(RadosGWStorage, self).get_direct_download_url(path, request_ip, expires_in, requires_cors,
-                                                               head)
+    return super(RadosGWStorage, self).get_direct_download_url(path, request_ip, expires_in,
+                                                               requires_cors, head)
 
   # TODO remove when radosgw supports cors: http://tracker.ceph.com/issues/8718#change-38624
   def get_direct_upload_url(self, path, mime_type, requires_cors=True):
@@ -621,9 +622,9 @@ class CloudFrontedS3Storage(S3Storage):
       
     resolved_ip_info = None
     logger.debug('Got direct download request for path "%s" with IP "%s"', path, request_ip)
-    if request_ip is not None and self._context.ip_resolver is not None:
-      # Lookup the IP address in our resolution table and determine whether it is under AWS. If it is,
-      # then return an S3 signed URL, since we are in-network.
+    if request_ip is not None:
+      # Lookup the IP address in our resolution table and determine whether it is under AWS.
+      # If it is, then return an S3 signed URL, since we are in-network.
       resolved_ip_info = self._context.ip_resolver.resolve_ip(request_ip)
       logger.debug('Resolved IP information for IP %s: %s', request_ip, resolved_ip_info)
       if resolved_ip_info and resolved_ip_info.provider == 'aws':

util/ipresolver/__init__.py

@@ -2,6 +2,9 @@ import logging
 import json
 import requests
 
+from abc import ABCMeta, abstractmethod
+from six import add_metaclass
+
 from cachetools import ttl_cache, lru_cache
 from collections import namedtuple, defaultdict
 from netaddr import IPNetwork, IPAddress, IPSet, AddrFormatError
@@ -9,6 +12,8 @@ from netaddr import IPNetwork, IPAddress, IPSet, AddrFormatError
 import geoip2.database
 import geoip2.errors
 
+from util.abchelpers import nooper
+
 ResolvedLocation = namedtuple('ResolvedLocation', ['provider', 'region', 'service', 'sync_token'])
 
 logger = logging.getLogger(__name__)
@@ -28,7 +33,25 @@ def update_resolver_datafiles():
       f.write(response.text)
       logger.debug('Successfully wrote %s', filename)
 
-class IPResolver(object):
+
+@add_metaclass(ABCMeta)
+class IPResolverInterface(object):
+  """ Helper class for resolving information about an IP address. """
+  @abstractmethod
+  def resolve_ip(self, ip_address):
+    """ Attempts to return resolved information about the specified IP Address. If such an attempt
+        fails, returns None.
+    """
+    pass
+
+
+@nooper
+class NoopIPResolver(IPResolverInterface):
+  """ No-op version of the security scanner API. """
+  pass
+
+
+class IPResolver(IPResolverInterface):
   def __init__(self, app):
     self.app = app
     self.geoip_db = geoip2.database.Reader('util/ipresolver/GeoLite2-Country.mmdb')