Nectar

When syncing from a registry which applies rate-limiting to requests, Pulp fails to handle the 429 response code ("Too many requests") and the sync task fails.

A better behaviour would be to back off when seeing 429, then retry.

In the particular instance of Quay.io, request limiting is applied per client IP address per second.

Related: DELIVERY-7214

2019-07-23 03:34:59 +0000 [ERROR   ] Pulp task [0d11937c-f11a-4ba5-b082-245febe02e1c] failed: PLP0000: Too Many Requests:
  Traceback (most recent call last):
    File "/usr/lib/python2.7/site-packages/celery/app/trace.py", line 367, in trace_task
      R = retval = fun(*args, **kwargs)
    File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 529, in __call__
      return super(Task, self).__call__(*args, **kwargs)
    File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 107, in __call__
      return super(PulpTask, self).__call__(*args, **kwargs)
    File "/usr/lib/python2.7/site-packages/celery/app/trace.py", line 622, in __protected_call__
      return self.run(*args, **kwargs)
    File "/usr/lib/python2.7/site-packages/pulp/server/controllers/repository.py", line 769, in sync
      sync_report = sync_repo(transfer_repo, conduit, call_config)
    File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 737, in wrap_f
      return f(*args, **kwargs)
    File "/usr/lib/python2.7/site-packages/pulp_docker/plugins/importers/importer.py", line 85, in sync_repo
      return self.sync_step.process_lifecycle()
    File "/usr/lib/python2.7/site-packages/pulp/plugins/util/publish_step.py", line 572, in process_lifecycle
      super(PluginStep, self).process_lifecycle()
    File "/usr/lib/python2.7/site-packages/pulp/plugins/util/publish_step.py", line 163, in process_lifecycle
      step.process()
    File "/usr/lib/python2.7/site-packages/pulp/plugins/util/publish_step.py", line 256, in process
      self._process_block()
    File "/usr/lib/python2.7/site-packages/pulp/plugins/util/publish_step.py", line 303, in _process_block
      self.process_main()
    File "/usr/lib/python2.7/site-packages/pulp_docker/plugins/importers/sync.py", line 224, in process_main
      available_tags = self.parent.index_repository.get_tags()
    File "/usr/lib/python2.7/site-packages/pulp_docker/plugins/registry.py", line 473, in get_tags
      headers, tags = self._get_path(link)
    File "/usr/lib/python2.7/site-packages/pulp_docker/plugins/registry.py", line 528, in _get_path
      self._raise_path_error(report)
    File "/usr/lib/python2.7/site-packages/pulp_docker/plugins/registry.py", line 550, in _raise_path_error
      raise IOError(report.error_msg)
  IOError: Too Many Requests