def on_put(self, request, response, queue):
"""Create a queue in the catalogue, then forwards to marconi.
This is the only time marconi proxy ever needs to select a
partition for a queue. The association is created in the
catalogue. This should also be the only time
partition.weighted_select is ever called.
:raises: HTTPInternalServerError - if no partitions are registered
"""
project = helpers.get_project(request)
# NOTE(cpp-cabrera): if we've already registered a queue,
# don't try to create it again, because it will duplicate it
# across partitions.
#
# There exists a race condition here, but it is benign. It's
# possible that after the existence check has succeeded,
# another request may succeed in DELETEing a queue. In this
# scenario, the queue will be recreated on another partition,
# which is reasonable, since the user meant to both DELETE and
# PUT That queue.
if lookup.exists(project, queue,
self._catalogue, self._cache):
response.status = falcon.HTTP_204
return
target = partition.weighted_select(self._partitions.list())
if target is None:
LOG.error('No partitions registered')
raise falcon.HTTPInternalServerError(
"No partitions registered",
"Contact the system administrator for more details."
)
host = target['hosts'][0]
resp = helpers.forward(host, request)
# NOTE(cpp-cabrera): only catalogue a queue if it was created
if resp.status_code == 201:
self._catalogue.insert(project, queue, target['name'],
host)
response.set_headers(helpers.capitalized(resp.headers))
response.status = http.status(resp.status_code)
response.body = resp.content
def on_get(self, request, response):
LOG.debug('GET v1')
partition = None
try:
partition = next(self._partitions.list())
except StopIteration:
LOG.error('GET v1 - no partitions registered')
raise falcon.HTTPServiceUnavailable(
"No partitions found",
"Register some partitions",
retry_after=120
)
host = partition['hosts'][0]
resp = helpers.forward(host, request)
response.set_headers(helpers.capitalized(resp.headers))
response.status = http.status(resp.status_code)
response.body = resp.content
def on_put(self, request, response, queue):
"""Create a queue in the catalogue, then forwards to marconi.
This is the only time marconi proxy ever needs to select a
partition for a queue. The association is created in the
catalogue. This should also be the only time
partition.weighted_select is ever called.
:raises: HTTPInternalServerError - if no partitions are registered
"""
project = helpers.get_project(request)
# NOTE(cpp-cabrera): if we've already registered a queue,
# don't try to create it again, because it will duplicate it
# across partitions.
#
# There exists a race condition here, but it is benign. It's
# possible that after the existence check has succeeded,
# another request may succeed in DELETEing a queue. In this
# scenario, the queue will be recreated on another partition,
# which is reasonable, since the user meant to both DELETE and
# PUT That queue.
if lookup.exists(project, queue, self._catalogue, self._cache):
response.status = falcon.HTTP_204
return
target = partition.weighted_select(self._partitions.list())
if target is None:
LOG.error('No partitions registered')
raise falcon.HTTPInternalServerError(
"No partitions registered",
"Contact the system administrator for more details.")
host = target['hosts'][0]
resp = helpers.forward(host, request)
# NOTE(cpp-cabrera): only catalogue a queue if it was created
if resp.status_code == 201:
self._catalogue.insert(project, queue, target['name'], host)
response.set_headers(helpers.capitalized(resp.headers))
response.status = http.status(resp.status_code)
response.body = resp.content
def forward(self, request, response, queue, **kwargs):
"""Forwards requests in a selector-driven fashion."""
project = helpers.get_project(request)
LOG.debug('FORWARD - project/queue: {0}/{1}'.format(
project, queue
))
partition = lookup.partition(project, queue,
self._catalogue,
self._cache)
# NOTE(cpp-cabrera): we tried to look up a catalogue
# entry and it failed. This happens if the associated
# queue doesn't exist under that project.
if not partition:
LOG.debug('Catalogue entry not found')
raise falcon.HTTPNotFound()
hosts = lookup.hosts(partition, self._partitions, self._cache)
# NOTE(cpp-cabrera): we tried to look up a partition, and it
# failed. This only happens if a partition is deleted from
# the primary store between here and the last call.
if not hosts:
LOG.debug('Partition not found')
raise falcon.HTTPNotFound()
# round robin to choose the desired host
host = self._selector.next(partition, hosts)
# send the request, update the response
resp = helpers.forward(host, request)
# NOTE(zyuan): normalize the lower-case header from
# `requests` to Caml-Case and forward the headers back
response.set_headers(helpers.capitalized(resp.headers))
response.status = http.status(resp.status_code)
response.body = resp.content
# NOTE(cpp-cabrera): in case responder must do more afterwards
return resp
def forward(self, request, response, queue, **kwargs):
"""Forwards requests in a selector-driven fashion."""
project = helpers.get_project(request)
LOG.debug('FORWARD - project/queue: {0}/{1}'.format(project, queue))
partition = lookup.partition(project, queue, self._catalogue,
self._cache)
# NOTE(cpp-cabrera): we tried to look up a catalogue
# entry and it failed. This happens if the associated
# queue doesn't exist under that project.
if not partition:
LOG.debug('Catalogue entry not found')
raise falcon.HTTPNotFound()
hosts = lookup.hosts(partition, self._partitions, self._cache)
# NOTE(cpp-cabrera): we tried to look up a partition, and it
# failed. This only happens if a partition is deleted from
# the primary store between here and the last call.
if not hosts:
LOG.debug('Partition not found')
raise falcon.HTTPNotFound()
# round robin to choose the desired host
host = self._selector.next(partition, hosts)
# send the request, update the response
resp = helpers.forward(host, request)
# NOTE(zyuan): normalize the lower-case header from
# `requests` to Caml-Case and forward the headers back
response.set_headers(helpers.capitalized(resp.headers))
response.status = http.status(resp.status_code)
response.body = resp.content
# NOTE(cpp-cabrera): in case responder must do more afterwards
return resp
