Debian Support

The following Ubuntu repository has Releases=bionic/mongodb-org/4.1:

Id:                  upstream_ubuntu-bionic-mongo-4.1_all
Display Name:        None
Description:         None
Content Unit Counts:
  Deb:           65
  Deb Component: 1
  Deb Release:   1
Notes:
Scratchpad:
Importers:
  Config:
    Architectures:  amd64
    Components:     multiverse
    Feed:           http://repo.mongodb.org/apt/ubuntu
    Releases:       bionic/mongodb-org/4.1
    SSL Validation: True
  Id:                   deb_importer
  Importer Type Id:     deb_importer
  Last Override Config:
  Last Sync:            2019-06-11T14:44:20Z
  Last Updated:         2019-06-11T14:43:57Z
  Repo Id:              upstream_ubuntu-bionic-mongo-4.1_all
  Scratchpad:           None
Distributors:
  Auto Publish:         True
  Config:
    Http:         False
    Https:        True
    Relative URL: upstream/ubuntu-bionic-mongo-4.1/all
  Distributor Type Id:  deb_distributor
  Id:                   deb_distributor
  Last Override Config:
  Last Publish:         2019-06-11T14:43:58Z
  Last Updated:         2019-06-11T12:38:38Z
  Repo Id:              upstream_ubuntu-bionic-mongo-4.1_all
  Scratchpad:

Because of the extra element in Releases (i.e bionic/mongodb-org/4.1 and not, say, bionic/mongodb-org-4.1), publishing breaks with:

2019-06-11T14:50:50.454921+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424) Exception caught from plugin during publish for repo [upstream_ubuntu-bionic-mongo-4.1_2019-06-11-144338]
2019-06-11T14:50:50.454995+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424) Traceback (most recent call last):
2019-06-11T14:50:50.454921+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424) Exception caught from plugin during publish for repo [upstream_ubuntu-bionic-mongo-4.1_2019-06-11-144338]
2019-06-11T14:50:50.454995+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424) Traceback (most recent call last):
2019-06-11T14:50:50.455057+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)   File "/usr/lib/python2.7/site-packages/pulp/server/controllers/repository.py", line 1259, in _do_publish
2019-06-11T14:50:50.455116+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)     publish_report = publish_repo(transfer_repo, conduit, call_config)
2019-06-11T14:50:50.455173+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)   File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 737, in wrap_f
2019-06-11T14:50:50.455229+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)     return f(*args, **kwargs)
2019-06-11T14:50:50.455303+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)   File "/usr/lib/python2.7/site-packages/pulp_deb/plugins/distributors/distributor.py", line 84, in publish_repo
2019-06-11T14:50:50.455362+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)     return self._publisher.process_lifecycle()
2019-06-11T14:50:50.455418+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)   File "/usr/lib/python2.7/site-packages/pulp/plugins/util/publish_step.py", line 573, in process_lifecycle
2019-06-11T14:50:50.455473+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)     super(PluginStep, self).process_lifecycle()
2019-06-11T14:50:50.455527+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)   File "/usr/lib/python2.7/site-packages/pulp/plugins/util/publish_step.py", line 164, in process_lifecycle
2019-06-11T14:50:50.455582+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)     step.process()
2019-06-11T14:50:50.455664+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)   File "/usr/lib/python2.7/site-packages/pulp/plugins/util/publish_step.py", line 257, in process
2019-06-11T14:50:50.455725+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)     self._process_block()
2019-06-11T14:50:50.455782+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)   File "/usr/lib/python2.7/site-packages/pulp/plugins/util/publish_step.py", line 304, in _process_block
2019-06-11T14:50:50.455840+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)     self.process_main()
2019-06-11T14:50:50.455895+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)   File "/usr/lib/python2.7/site-packages/pulp_deb/plugins/distributors/distributor.py", line 360, in process_main
2019-06-11T14:50:50.455950+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424)     os.mkdir(release_path)
2019-06-11T14:50:50.456007+00:00 host pulp[24687]: pulp.server.controllers.repository:ERROR: [e9969ccf] (24687-63424) OSError: [Errno 2] No such file or directory: '/var/cache/pulp/reserved_resource_worker-0@host/e9969ccf-aa8d-4bb4-9249-e43553b251d9/dists/bionic/mongodb-org'

Changing https://github.com/pulp/pulp_deb/blob/1.9-release/plugins/pulp_deb/plugins/distributors/distributor.py#L360 from `os.mkdir(release_path)` to `os.makedirs(release_path)` fixes the problem.