Steve Baker ad475ee927 Collector which does a simple HTTP GET
This change implements a collector which does an HTTP GET via
python requests to fetch the metadata.

It should work with any GET-able URL, however it is designed to
work with Swift TempURLs.

Swift objects are not consistent, so the Last-Modified header is
checked for each poll and metadata is not fetched if the last
modified is not newer than the previous successful poll.

This collector will be enabled for OS::Nova::Server
software_config_transport: POLL_TEMP_URL which is available
in the Juno release of Heat. Using POLL_TEMP_URL will result
in no metadata polling load on heat, which has historically been
an issue with tripleo scalability.

Change-Id: I22155c22bdcc3c81a5e945ca5436a8f29f196528
2014-10-17 09:40:23 +13:00

149 lines
4.8 KiB
Python

# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
#
# 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 calendar
import json
import time
import fixtures
from oslo.config import cfg
import requests
import testtools
from testtools import matchers
from os_collect_config import collect
from os_collect_config import exc
from os_collect_config import request
META_DATA = {u'int1': 1,
u'strfoo': u'foo',
u'map_ab': {
u'a': 'apple',
u'b': 'banana',
}}
class FakeResponse(dict):
def __init__(self, text, headers=None):
self.text = text
self.headers = headers
def raise_for_status(self):
pass
class FakeRequests(object):
exceptions = requests.exceptions
class Session(object):
def get(self, url):
return FakeResponse(json.dumps(META_DATA))
def head(self, url):
return FakeResponse('', headers={
'last-modified': time.strftime(
"%a, %d %b %Y %H:%M:%S %Z", time.gmtime())})
class FakeFailRequests(object):
exceptions = requests.exceptions
class Session(object):
def get(self, url):
raise requests.exceptions.HTTPError(403, 'Forbidden')
def head(self, url):
raise requests.exceptions.HTTPError(403, 'Forbidden')
class TestRequestBase(testtools.TestCase):
def setUp(self):
super(TestRequestBase, self).setUp()
self.log = self.useFixture(fixtures.FakeLogger())
collect.setup_conf()
cfg.CONF.request.metadata_url = 'http://127.0.0.1:8000/my_metadata'
class TestRequest(TestRequestBase):
def test_collect_request(self):
req_collect = request.Collector(requests_impl=FakeRequests)
self.assertIsNone(req_collect.last_modified)
req_md = req_collect.collect()
self.assertIsNotNone(req_collect.last_modified)
self.assertThat(req_md, matchers.IsInstance(list))
self.assertEqual('request', req_md[0][0])
req_md = req_md[0][1]
for k in ('int1', 'strfoo', 'map_ab'):
self.assertIn(k, req_md)
self.assertEqual(req_md[k], META_DATA[k])
self.assertEqual('', self.log.output)
def test_collect_request_fail(self):
req_collect = request.Collector(requests_impl=FakeFailRequests)
self.assertRaises(exc.RequestMetadataNotAvailable, req_collect.collect)
self.assertIn('Forbidden', self.log.output)
def test_collect_request_no_metadata_url(self):
cfg.CONF.request.metadata_url = None
req_collect = request.Collector(requests_impl=FakeRequests)
self.assertRaises(exc.RequestMetadataNotConfigured,
req_collect.collect)
self.assertIn('No metadata_url configured', self.log.output)
def test_check_fetch_content(self):
req_collect = request.Collector()
now_secs = calendar.timegm(time.gmtime())
now_str = time.strftime("%a, %d %b %Y %H:%M:%S %Z",
time.gmtime(now_secs))
future_secs = calendar.timegm(time.gmtime()) + 10
future_str = time.strftime("%a, %d %b %Y %H:%M:%S %Z",
time.gmtime(future_secs))
past_secs = calendar.timegm(time.gmtime()) - 10
past_str = time.strftime("%a, %d %b %Y %H:%M:%S %Z",
time.gmtime(past_secs))
self.assertIsNone(req_collect.last_modified)
# first run always collects
self.assertEqual(
now_secs,
req_collect.check_fetch_content({'last-modified': now_str}))
# second run unmodified, does not collect
req_collect.last_modified = now_secs
self.assertRaises(exc.RequestMetadataNotAvailable,
req_collect.check_fetch_content,
{'last-modified': now_str})
# run with later date, collects
self.assertEqual(
future_secs,
req_collect.check_fetch_content({'last-modified': future_str}))
# run with earlier date, does not collect
self.assertRaises(exc.RequestMetadataNotAvailable,
req_collect.check_fetch_content,
{'last-modified': past_str})
# run no last-modified header, collects
self.assertIsNone(req_collect.check_fetch_content({}))