Merge pull request splitio#237 from splitio/development

Development

Author: mmelograno

CHANGES.txt

@@ -1,3 +1,7 @@
+9.1.0 (Jul 15, 2021)
+- Added Cache-Control header for on-demand requests to sdk-server.
+- Updated the synchronization flow to be more reliable in the event of an edge case generating delay in cache purge propagation, keeping the SDK cache properly synced.
+
 9.0.0 (May 3, 2021)
  - BREAKING CHANGE: Removed splitSdkMachineIp and splitSdkMachineName configs.
  - BREAKING CHANGE: Deprecated `redisCharset` config.

splitio/api/__init__.py

@@ -13,31 +13,3 @@ def __init__(self, custom_message, status_code=None):
     def status_code(self):
         """Return HTTP status code."""
         return self._status_code
-
-
-def headers_from_metadata(sdk_metadata, client_key=None):
-    """
-    Generate a dict with headers required by data-recording API endpoints.
-
-    :param sdk_metadata: SDK Metadata object, generated at sdk initialization time.
-    :type sdk_metadata: splitio.client.util.SdkMetadata
-
-    :param client_key: client key.
-    :type client_key: str
-
-    :return: A dictionary with headers.
-    :rtype: dict
-    """
-
-    metadata = {
-        'SplitSDKVersion': sdk_metadata.sdk_version,
-        'SplitSDKMachineIP': sdk_metadata.instance_ip,
-        'SplitSDKMachineName': sdk_metadata.instance_name
-    } if sdk_metadata.instance_ip != 'NA' and sdk_metadata.instance_ip != 'unknown' else {
-        'SplitSDKVersion': sdk_metadata.sdk_version,
-    }
-
-    if client_key is not None:
-        metadata['SplitSDKClientKey'] = client_key
-
-    return metadata

splitio/api/auth.py

@@ -3,7 +3,8 @@
 import logging
 import json
 
-from splitio.api import APIException, headers_from_metadata
+from splitio.api import APIException
+from splitio.api.commons import headers_from_metadata
 from splitio.api.client import HttpClientException
 from splitio.models.token import from_raw
 

splitio/api/commons.py

@@ -0,0 +1,95 @@
+"""Commons module."""
+
+
+_CACHE_CONTROL = 'Cache-Control'
+_CACHE_CONTROL_NO_CACHE = 'no-cache'
+
+
+def headers_from_metadata(sdk_metadata, client_key=None):
+    """
+    Generate a dict with headers required by data-recording API endpoints.
+
+    :param sdk_metadata: SDK Metadata object, generated at sdk initialization time.
+    :type sdk_metadata: splitio.client.util.SdkMetadata
+
+    :param client_key: client key.
+    :type client_key: str
+
+    :return: A dictionary with headers.
+    :rtype: dict
+    """
+
+    metadata = {
+        'SplitSDKVersion': sdk_metadata.sdk_version,
+        'SplitSDKMachineIP': sdk_metadata.instance_ip,
+        'SplitSDKMachineName': sdk_metadata.instance_name
+    } if sdk_metadata.instance_ip != 'NA' and sdk_metadata.instance_ip != 'unknown' else {
+        'SplitSDKVersion': sdk_metadata.sdk_version,
+    }
+
+    if client_key is not None:
+        metadata['SplitSDKClientKey'] = client_key
+
+    return metadata
+
+
+class FetchOptions(object):
+    """Fetch Options object."""
+
+    def __init__(self, cache_control_headers=False, change_number=None):
+        """
+        Class constructor.
+
+        :param cache_control_headers: Flag for Cache-Control header
+        :type cache_control_headers: bool
+
+        :param change_number: ChangeNumber to use for bypassing CDN in request.
+        :type change_number: int
+        """
+        self._cache_control_headers = cache_control_headers
+        self._change_number = change_number
+
+    @property
+    def cache_control_headers(self):
+        """Return cache control headers."""
+        return self._cache_control_headers
+
+    @property
+    def change_number(self):
+        """Return change number."""
+        return self._change_number
+
+    def __eq__(self, other):
+        """Match between other options."""
+        if self._cache_control_headers != other._cache_control_headers:
+            return False
+        if self._change_number != other._change_number:
+            return False
+        return True
+
+
+def build_fetch(change_number, fetch_options, metadata):
+    """
+    Build fetch with new flags if that is the case.
+
+    :param change_number: Last known timestamp of definition.
+    :type change_number: int
+
+    :param fetch_options: Fetch options for getting definitions.
+    :type fetch_options: splitio.api.commons.FetchOptions
+
+    :param metadata: Metadata Headers.
+    :type metadata: dict
+
+    :return: Objects for fetch
+    :rtype: dict, dict
+    """
+    query = {'since': change_number}
+    extra_headers = metadata
+    if fetch_options is None:
+        return query, extra_headers
+    if fetch_options.cache_control_headers:
+        extra_headers[_CACHE_CONTROL] = _CACHE_CONTROL_NO_CACHE
+    if fetch_options.change_number is not None:
+        query['till'] = fetch_options.change_number
+    return query, extra_headers

splitio/api/events.py

@@ -1,8 +1,9 @@
 """Events API module."""
 import logging
 
-from splitio.api import APIException, headers_from_metadata
+from splitio.api import APIException
 from splitio.api.client import HttpClientException
+from splitio.api.commons import headers_from_metadata
 
 
 _LOGGER = logging.getLogger(__name__)

splitio/api/impressions.py

@@ -3,8 +3,9 @@
 import logging
 from itertools import groupby
 
-from splitio.api import APIException, headers_from_metadata
+from splitio.api import APIException
 from splitio.api.client import HttpClientException
+from splitio.api.commons import headers_from_metadata
 from splitio.engine.impressions import ImpressionsMode
 
 

splitio/api/segments.py

@@ -3,7 +3,8 @@
 import json
 import logging
 
-from splitio.api import APIException, headers_from_metadata
+from splitio.api import APIException
+from splitio.api.commons import headers_from_metadata, build_fetch
 from splitio.api.client import HttpClientException
 
 
@@ -29,25 +30,30 @@ def __init__(self, http_client, apikey, sdk_metadata):
         self._apikey = apikey
         self._metadata = headers_from_metadata(sdk_metadata)
 
-    def fetch_segment(self, segment_name, change_number):
+    def fetch_segment(self, segment_name, change_number, fetch_options):
         """
         Fetch splits from backend.
 
         :param segment_name: Name of the segment to fetch changes for.
         :type segment_name: str
-        :param change_number: Last known timestamp of a split modification.
+
+        :param change_number: Last known timestamp of a segment modification.
         :type change_number: int
 
+        :param fetch_options: Fetch options for getting segment definitions.
+        :type fetch_options: splitio.api.commons.FetchOptions
+
         :return: Json representation of a segmentChange response.
         :rtype: dict
         """
         try:
+            query, extra_headers = build_fetch(change_number, fetch_options, self._metadata)
             response = self._client.get(
                 'sdk',
                 '/segmentChanges/{segment_name}'.format(segment_name=segment_name),
                 self._apikey,
-                extra_headers=self._metadata,
-                query={'since': change_number}
+                extra_headers=extra_headers,
+                query=query,
             )
 
             if 200 <= response.status_code < 300:

splitio/api/splits.py

@@ -3,7 +3,8 @@
 import logging
 import json
 
-from splitio.api import APIException, headers_from_metadata
+from splitio.api import APIException
+from splitio.api.commons import headers_from_metadata, build_fetch
 from splitio.api.client import HttpClientException
 
 
@@ -28,23 +29,27 @@ def __init__(self, client, apikey, sdk_metadata):
         self._apikey = apikey
         self._metadata = headers_from_metadata(sdk_metadata)
 
-    def fetch_splits(self, change_number):
+    def fetch_splits(self, change_number, fetch_options):
         """
         Fetch splits from backend.
 
-        :param changeNumber: Last known timestamp of a split modification.
-        :type changeNumber: int
+        :param change_number: Last known timestamp of a split modification.
+        :type change_number: int
+
+        :param fetch_options: Fetch options for getting split definitions.
+        :type fetch_options: splitio.api.commons.FetchOptions
 
         :return: Json representation of a splitChanges response.
         :rtype: dict
         """
         try:
+            query, extra_headers = build_fetch(change_number, fetch_options, self._metadata)
             response = self._client.get(
                 'sdk',
                 '/splitChanges',
                 self._apikey,
-                extra_headers=self._metadata,
-                query={'since': change_number}
+                extra_headers=extra_headers,
+                query=query,
             )
             if 200 <= response.status_code < 300:
                 return json.loads(response.body)

splitio/api/telemetry.py

@@ -1,7 +1,8 @@
 """Telemetry API Module."""
 import logging
 
-from splitio.api import APIException, headers_from_metadata
+from splitio.api import APIException
+from splitio.api.commons import headers_from_metadata
 from splitio.api.client import HttpClientException
 
 

splitio/client/input_validator.py

@@ -5,6 +5,7 @@
 import math
 
 from splitio.api import APIException
+from splitio.api.commons import FetchOptions
 from splitio.client.key import Key
 from splitio.engine.evaluator import CONTROL
 
@@ -458,7 +459,7 @@ def validate_apikey_type(segment_api):
     _logger = logging.getLogger('splitio.api.segments')
     try:
         _logger.addFilter(api_messages_filter)  # pylint: disable=protected-access
-        segment_api.fetch_segment('__SOME_INVALID_SEGMENT__', -1)
+        segment_api.fetch_segment('__SOME_INVALID_SEGMENT__', -1, FetchOptions())
     except APIException as exc:
         if exc.status_code == 403:
             _LOGGER.error('factory instantiation: you passed a browser type '