text: import asyncio
  import datetime
  import logging
  
  import pykube
  import requests
  
  from kopf import config
  from kopf.clients import auth
  from kopf.structs import hierarchies
  
  logger = logging.getLogger(__name__)
  
  MAX_MESSAGE_LENGTH = 1024
  CUT_MESSAGE_INFIX = '...'
  
  
  async def post_event(*, obj=None, ref=None, type, reason, message=''):
      """
      Issue an event for the object.
  
      This is where they can also be accumulated, aggregated, grouped,
      and where the rate-limits should be maintained. It can (and should)
      be done by the client library, as it is done in the Go client.
      """
  
      # Object reference - similar to the owner reference, but different.
      if obj is not None and ref is not None:
          raise TypeError("Only one of obj= and ref= is allowed for a posted event. Got both.")
      if obj is None and ref is None:
          raise TypeError("One of obj= and ref= is required for a posted event. Got none.")
      if ref is None:
          ref = hierarchies.build_object_reference(obj)
  
      now = datetime.datetime.utcnow()
  
      # See #164. For cluster-scoped objects, use the current namespace from the current context.
      # It could be "default", but in some systems, we are limited to one specific namespace only.
      namespace = ref.get('namespace') or auth.get_pykube_cfg().namespace
      if not ref.get('namespace'):
          ref = dict(ref, namespace=namespace)
  
      # Prevent a common case of event posting errors but shortening the message.
      if len(message) > MAX_MESSAGE_LENGTH:
          infix = CUT_MESSAGE_INFIX
          prefix = message[:MAX_MESSAGE_LENGTH // 2 - (len(infix) // 2)]
          suffix = message[-MAX_MESSAGE_LENGTH // 2 + (len(infix) - len(infix) // 2):]
          message = f'{prefix}{infix}{suffix}'
  
      body = {
          'metadata': {
              'namespace': namespace,
              'generateName': 'kopf-event-',
          },
  
          'action': 'Action?',
          'type': type,
          'reason': reason,
          'message': message,
  
          'reportingComponent': 'kopf',
          'reportingInstance': 'dev',
          'source' : {'component': 'kopf'},  # used in the "From" column in `kubectl describe`.
  
          'involvedObject': ref,
  
          'firstTimestamp': now.isoformat() + 'Z',  # '2019-01-28T18:25:03.000000Z' -- seen in `kubectl describe ...`
          'lastTimestamp': now.isoformat() + 'Z',  # '2019-01-28T18:25:03.000000Z' - seen in `kubectl get events`
          'eventTime': now.isoformat() + 'Z',  # '2019-01-28T18:25:03.000000Z'
      }
  
      try:
          api = auth.get_pykube_api()
          obj = pykube.Event(api, body)
  
          loop = asyncio.get_running_loop()
          await loop.run_in_executor(config.WorkersConfig.get_syn_executor(), obj.create)
  
      except (requests.exceptions.HTTPError, pykube.exceptions.HTTPError) as e:
          # Events are helpful but auxiliary, they should not fail the handling cycle.
          # Yet we want to notice that something went wrong (in logs).
          logger.warning("Failed to post an event. Ignoring and continuing. "
                         f"Error: {e!r}. "
                         f"Event: type={type!r}, reason={reason!r}, message={message!r}.")
  