fix(kubernetes): temporary solution for updated k8s python client

kubernetes/base/watch/watch.py

@@ -0,0 +1,213 @@
+# Copyright 2016 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+
+import json
+import pydoc
+import sys
+
+from kubernetes import client
+
+PYDOC_RETURN_LABEL = ":return:"
+PYDOC_FOLLOW_PARAM = ":param bool follow:"
+
+# Removing this suffix from return type name should give us event's object
+# type. e.g., if list_namespaces() returns "NamespaceList" type,
+# then list_namespaces(watch=true) returns a stream of events with objects
+# of type "Namespace". In case this assumption is not true, user should
+# provide return_type to Watch class's __init__.
+TYPE_LIST_SUFFIX = "List"
+
+
+PY2 = sys.version_info[0] == 2
+if PY2:
+    import httplib
+    HTTP_STATUS_GONE = httplib.GONE
+else:
+    import http
+    HTTP_STATUS_GONE = http.HTTPStatus.GONE
+
+
+class SimpleNamespace:
+
+    def __init__(self, **kwargs):
+        self.__dict__.update(kwargs)
+
+
+def _find_return_type(func):
+    for line in pydoc.getdoc(func).splitlines():
+        if line.startswith(PYDOC_RETURN_LABEL):
+            return line[len(PYDOC_RETURN_LABEL):].strip()
+    return ""
+
+
+def iter_resp_lines(resp):
+    buffer = bytearray()
+    for segment in resp.stream(amt=None, decode_content=False):
+
+        # Append the segment (chunk) to the buffer
+        #
+        # Performance note: depending on contents of buffer and the type+value of segment,
+        # encoding segment into the buffer could be a wasteful step. The approach used here
+        # simplifies the logic farther down, but in the future it may be reasonable to
+        # sacrifice readability for performance.
+        if isinstance(segment, bytes):
+            buffer.extend(segment)
+        elif isinstance(segment, str):
+            buffer.extend(segment.encode("utf-8"))
+        else:
+            raise TypeError(
+                f"Received invalid segment type, {type(segment)}, from stream. Accepts only 'str' or 'bytes'.")
+
+        # Split by newline (safe for utf-8 because multi-byte sequences cannot contain the newline byte)
+        next_newline = buffer.find(b'\n')
+        while next_newline != -1:
+            # Convert bytes to a valid utf-8 string, replacing any invalid utf-8 with the '<27>' character
+            line = buffer[:next_newline].decode(
+                "utf-8", errors="replace")
+            buffer = buffer[next_newline+1:]
+            if line:
+                yield line
+            next_newline = buffer.find(b'\n')
+
+
+class Watch(object):
+
+    def __init__(self, return_type=None):
+        self._raw_return_type = return_type
+        self._stop = False
+        self._api_client = client.ApiClient()
+        self.resource_version = None
+
+    def stop(self):
+        self._stop = True
+
+    def get_return_type(self, func):
+        if self._raw_return_type:
+            return self._raw_return_type
+        return_type = _find_return_type(func)
+        if return_type.endswith(TYPE_LIST_SUFFIX):
+            return return_type[:-len(TYPE_LIST_SUFFIX)]
+        return return_type
+
+    def get_watch_argument_name(self, func):
+        if PYDOC_FOLLOW_PARAM in pydoc.getdoc(func):
+            return 'follow'
+        else:
+            return 'watch'
+
+    def unmarshal_event(self, data, return_type):
+        js = json.loads(data)
+        js['raw_object'] = js['object']
+        # BOOKMARK event is treated the same as ERROR for a quick fix of
+        # decoding exception
+        # TODO: make use of the resource_version in BOOKMARK event for more
+        # efficient WATCH
+        if return_type and js['type'] != 'ERROR' and js['type'] != 'BOOKMARK':
+            obj = SimpleNamespace(data=json.dumps(js['raw_object']))
+            js['object'] = self._api_client.deserialize(obj, return_type)
+            if hasattr(js['object'], 'metadata'):
+                self.resource_version = js['object'].metadata.resource_version
+            # For custom objects that we don't have model defined, json
+            # deserialization results in dictionary
+            elif (isinstance(js['object'], dict) and 'metadata' in js['object']
+                  and 'resourceVersion' in js['object']['metadata']):
+                self.resource_version = js['object']['metadata'][
+                    'resourceVersion']
+        return js
+
+    def stream(self, func, *args, **kwargs):
+        """Watch an API resource and stream the result back via a generator.
+
+        Note that watching an API resource can expire. The method tries to
+        resume automatically once from the last result, but if that last result
+        is too old as well, an `ApiException` exception will be thrown with
+        ``code`` 410. In that case you have to recover yourself, probably
+        by listing the API resource to obtain the latest state and then
+        watching from that state on by setting ``resource_version`` to
+        one returned from listing.
+
+        :param func: The API function pointer. Any parameter to the function
+                     can be passed after this parameter.
+
+        :return: Event object with these keys:
+                   'type': The type of event such as "ADDED", "DELETED", etc.
+                   'raw_object': a dict representing the watched object.
+                   'object': A model representation of raw_object. The name of
+                             model will be determined based on
+                             the func's doc string. If it cannot be determined,
+                             'object' value will be the same as 'raw_object'.
+
+        Example:
+            v1 = kubernetes.client.CoreV1Api()
+            watch = kubernetes.watch.Watch()
+            for e in watch.stream(v1.list_namespace, resource_version=1127):
+                type_ = e['type']
+                object_ = e['object']  # object is one of type return_type
+                raw_object = e['raw_object']  # raw_object is a dict
+                ...
+                if should_stop:
+                    watch.stop()
+        """
+
+        self._stop = False
+        return_type = self.get_return_type(func)
+        watch_arg = self.get_watch_argument_name(func)
+        kwargs[watch_arg] = True
+        kwargs['_preload_content'] = False
+        if 'resource_version' in kwargs:
+            self.resource_version = kwargs['resource_version']
+
+        # Do not attempt retries if user specifies a timeout.
+        # We want to ensure we are returning within that timeout.
+        disable_retries = ('timeout_seconds' in kwargs)
+        retry_after_410 = False
+        while True:
+            resp = func(*args, **kwargs)
+            try:
+                for line in iter_resp_lines(resp):
+                    # unmarshal when we are receiving events from watch,
+                    # return raw string when we are streaming log
+                    if watch_arg == "watch":
+                        event = self.unmarshal_event(line, return_type)
+                        if isinstance(event, dict) \
+                                and event['type'] == 'ERROR':
+                            obj = event['raw_object']
+                            # Current request expired, let's retry, (if enabled)
+                            # but only if we have not already retried.
+                            if not disable_retries and not retry_after_410 and \
+                                    obj['code'] == HTTP_STATUS_GONE:
+                                retry_after_410 = True
+                                break
+                            else:
+                                reason = "%s: %s" % (
+                                    obj['reason'], obj['message'])
+                                raise client.rest.ApiException(
+                                    status=obj['code'], reason=reason)
+                        else:
+                            retry_after_410 = False
+                            yield event
+                    else:
+                        yield line
+                    if self._stop:
+                        break
+            finally:
+                resp.close()
+                resp.release_conn()
+                if self.resource_version is not None:
+                    kwargs['resource_version'] = self.resource_version
+                else:
+                    self._stop = True
+
+            if self._stop or disable_retries:
+                break