Actual implementation of CloudFormation

os_collect_config/cfn.py

@@ -13,47 +13,70 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 from oslo.config import cfg
-import requests
 
 from openstack.common import log
+from os_collect_config import common
 from os_collect_config import exc
 
 EC2_METADATA_URL = 'http://169.254.169.254/latest/meta-data'
 CONF = cfg.CONF
+logger = log.getLogger(__name__)
 
 opts = [
     cfg.StrOpt('metadata-url',
                help='URL to query for CloudFormation Metadata'),
+    cfg.StrOpt('stack-name',
+               help='Stack name to describe'),
     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
+class CollectCfn(object):
+    def __init__(self, requests_impl=common.requests):
+        self._requests_impl = requests_impl
+        self._session = requests_impl.Session()
 
+    def collect(self):
+        if CONF.cfn.metadata_url is None:
+            logger.warn('No metadata_url configured.')
+            raise exc.CfnMetadataNotConfigured
+        url = CONF.cfn.metadata_url
+        stack_name = CONF.cfn.stack_name
+        headers = {'Content-Type': 'application/json'}
+        final_content = {}
+        if CONF.cfn.path is None:
+            logger.warn('No path configured')
+            raise exc.CfnMetadataNotConfigured
 
-def collect():
-    root_url = '%s/' % (CONF.ec2.metadata_url)
-    session = requests.Session()
-    return _fetch_metadata(root_url, session)
+        for path in CONF.cfn.path:
+            if '.' not in path:
+                logger.error('Path not in format resource.field[.x.y] (%s)' %
+                             path)
+                raise exc.CfnMetadataNotConfigured
+            resource, field = path.split('.', 1)
+            if '.' in field:
+                field, sub_path = field.split('.', 1)
+            else:
+                sub_path = ''
+                params = {'Action': 'DescribeStackResource',
+                          'Stackname': stack_name,
+                          'LogicalResourceId': resource}
+            try:
+                content = self._session.get(
+                    url, params=params, headers=headers)
+            except self._requests_impl.exceptions.RequestException as e:
+                logger.warn(e)
+                raise exc.CfnMetadataNotAvailable
+            map_content = json.loads(content.text)
+            if sub_path:
+                if sub_path not in map_content:
+                    logger.warn('Sub-path could not be found for Resource (%s)'
+                                % path)
+                    raise exc.CfnMetadataNotConfigured
+                map_content = map_content[sub_path]
+
+            final_content.update(map_content)
+        return final_content

os_collect_config/collect.py

@@ -19,6 +19,7 @@ import subprocess
 
 from openstack.common import log
 from os_collect_config import cache
+from os_collect_config import cfn
 from os_collect_config import common
 from os_collect_config import ec2
 from oslo.config import cfg
@@ -40,8 +41,13 @@ def setup_conf():
     ec2_group = cfg.OptGroup(name='ec2',
                              title='EC2 Metadata options')
 
+    cfn_group = cfg.OptGroup(name='cfn',
+                             title='CloudFormation API Metadata options')
+
     CONF.register_group(ec2_group)
+    CONF.register_group(cfn_group)
     CONF.register_cli_opts(ec2.opts, group='ec2')
+    CONF.register_cli_opts(cfn.opts, group='cfn')
 
     CONF.register_cli_opts(opts)
 

os_collect_config/exc.py

@@ -8,3 +8,7 @@ class Ec2MetadataNotAvailable(SourceNotAvailable):
 
 class CfnMetadataNotAvailable(SourceNotAvailable):
     """The cfn metadata service is not available."""
+
+
+class CfnMetadataNotConfigured(SourceNotAvailable):
+    """The cfn metadata service is not fully configured."""

os_collect_config/tests/test_cfn.py

@@ -15,6 +15,7 @@
 
 import fixtures
 import json
+from oslo.config import cfg
 import requests
 import testtools
 from testtools import matchers
@@ -41,47 +42,65 @@ class FakeResponse(dict):
         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 FakeRequests(object):
+    exceptions = requests.exceptions
+
+    def __init__(self, testcase):
+        self._test = testcase
+
+    def Session(self):
+        class FakeReqSession(object):
+            def __init__(self, testcase):
+                self._test = testcase
+
+            def get(self, url, params, headers):
+                url = urlparse.urlparse(url)
+                self._test.assertEquals('/', url.path)
+                self._test.assertEquals('application/json',
+                                        headers['Content-Type'])
+                # TODO(clint-fewbar) Refactor usage of requests to a factory
+                self._test.assertIn('Action', params)
+                self._test.assertEquals('DescribeStackResource',
+                                        params['Action'])
+                self._test.assertIn('LogicalResourceId', params)
+                self._test.assertEquals('foo', params['LogicalResourceId'])
+                return FakeResponse(json.dumps(META_DATA))
+        return FakeReqSession(self._test)
 
 
-class FakeFailSession(object):
-    def get(self, url):
-        raise requests.exceptions.HTTPError(403, 'Forbidden')
+class FakeFailRequests(object):
+    exceptions = requests.exceptions
+
+    class Session(object):
+        def get(self, url, params, headers):
+            raise requests.exceptions.HTTPError(403, 'Forbidden')
 
 
 class TestCfn(testtools.TestCase):
     def setUp(self):
         super(TestCfn, self).setUp()
         self.log = self.useFixture(fixtures.FakeLogger())
+        collect.setup_conf()
+        cfg.CONF.cfn.metadata_url = 'http://127.0.0.1:8000/'
+        cfg.CONF.cfn.path = ['foo.Metadata']
 
     def test_collect_cfn(self):
-        self.useFixture(
-            fixtures.MonkeyPatch('requests.Session', FakeSession))
-        collect.setup_conf()
-        cfn_md = cfn.collect()
+        cfn_md = cfn.CollectCfn(requests_impl=FakeRequests(self)).collect()
         self.assertThat(cfn_md, matchers.IsInstance(dict))
 
-        for k in ('int1', 'strfoo', 'mapab'):
+        for k in ('int1', 'strfoo', 'map_ab'):
             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)
+        cfn_collect = cfn.CollectCfn(requests_impl=FakeFailRequests)
+        self.assertRaises(exc.CfnMetadataNotAvailable, cfn_collect.collect)
         self.assertIn('Forbidden', self.log.output)
+
+    def test_collect_cfn_no_path(self):
+        cfg.CONF.cfn.path = None
+        cfn_collect = cfn.CollectCfn(requests_impl=FakeRequests(self))
+        self.assertRaises(exc.CfnMetadataNotConfigured, cfn_collect.collect)
+        self.assertIn('No path configured', self.log.output)

os_collect_config/tests/test_collect.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import extras
 import fixtures
 import json
 import os
@@ -86,3 +87,5 @@ class TestConf(testtools.TestCase):
     def test_setup_conf(self):
         collect.setup_conf()
         self.assertEquals('/var/run/os-collect-config', cfg.CONF.cachedir)
+        self.assertTrue(extras.safe_hasattr(cfg.CONF, 'ec2'))
+        self.assertTrue(extras.safe_hasattr(cfg.CONF, 'cfn'))