Skeleton implementation of cfn

os_collect_config/cfn.py

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+# 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.
+
+from oslo.config import cfg
+import requests
+
+from openstack.common import log
+from os_collect_config import exc
+
+EC2_METADATA_URL = 'http://169.254.169.254/latest/meta-data'
+CONF = cfg.CONF
+
+opts = [
+    cfg.StrOpt('metadata-url',
+               help='URL to query for CloudFormation Metadata'),
+    cfg.MultiStrOpt('path',
+                    help='Path to Metadata'),
+]
+
+
+def _fetch_metadata(fetch_url, session):
+    try:
+        r = session.get(fetch_url)
+        r.raise_for_status()
+    except (requests.HTTPError,
+            requests.ConnectionError,
+            requests.Timeout) as e:
+        log.getLogger(__name__).warn(e)
+        raise exc.Ec2MetadataNotAvailable
+    content = r.text
+    if fetch_url[-1] == '/':
+        new_content = {}
+        for subkey in content.split("\n"):
+            if '=' in subkey:
+                subkey = subkey[:subkey.index('=')] + '/'
+            sub_fetch_url = fetch_url + subkey
+            if subkey[-1] == '/':
+                subkey = subkey[:-1]
+            new_content[subkey] = _fetch_metadata(sub_fetch_url, session)
+        content = new_content
+    return content
+
+
+def collect():
+    root_url = '%s/' % (CONF.ec2.metadata_url)
+    session = requests.Session()
+    return _fetch_metadata(root_url, session)

os_collect_config/tests/test_cfn.py

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+# 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 fixtures
+import json
+import requests
+import testtools
+from testtools import matchers
+import urlparse
+
+from os_collect_config import cfn
+from os_collect_config import collect
+from os_collect_config import exc
+
+
+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):
+        self.text = text
+
+    def raise_for_status(self):
+        pass
+
+
+class FakeSession(object):
+    def get(self, url):
+        url = urlparse.urlparse(url)
+        params = urlparse.parse_qsl(url.query)
+        # TODO(clint-fewbar) Refactor usage of requests to a factory
+        if 'Action' not in params:
+            raise Exception('No Action')
+        if params['Action'] != 'DescribeStackResources':
+            raise Exception('Wrong Action (%s)' % params['Action'])
+        return FakeResponse(json.dumps(META_DATA))
+
+
+class FakeFailSession(object):
+    def get(self, url):
+        raise requests.exceptions.HTTPError(403, 'Forbidden')
+
+
+class TestCfn(testtools.TestCase):
+    def setUp(self):
+        super(TestCfn, self).setUp()
+        self.log = self.useFixture(fixtures.FakeLogger())
+
+    def test_collect_cfn(self):
+        self.useFixture(
+            fixtures.MonkeyPatch('requests.Session', FakeSession))
+        collect.setup_conf()
+        cfn_md = cfn.collect()
+        self.assertThat(cfn_md, matchers.IsInstance(dict))
+
+        for k in ('int1', 'strfoo', 'mapab'):
+            self.assertIn(k, cfn_md)
+            self.assertEquals(cfn_md[k], META_DATA[k])
+
+        self.assertEquals(cfn_md['block-device-mapping']['ami'], 'vda')
+
+        self.assertEquals('', self.log.output)
+
+    def test_collect_cfn_fail(self):
+        self.useFixture(
+            fixtures.MonkeyPatch(
+                'requests.Session', FakeFailSession))
+        collect.setup_conf()
+        self.assertRaises(exc.CfnMetadataNotAvailable, cfn.collect)
+        self.assertIn('Forbidden', self.log.output)