Make ceilometer work correctly when hosted with a SCRIPT_NAME

In the past ceilometer was generaly hosted at / and URL generation
was relatively straightforward. It should also be possible to host
at /foobar or /telemetry and for URL generation to still work. This
changeset adds tests to confirm prefixed requests can work and fixes
the small number of issues that were found.

Note that because the ceilometer api has the temerity to not set
location headers, we can't test that those are working, because
there aren't any. In general that's the place where SCRIPT_NAME
mounting would show bugs.

But we can confirm that content-location headers are okay.

Closes-Bug: #1468796
Change-Id: I6e5cf440bc3bd8ffb4cc5c86aa19225b3c5f87ed

.testr.conf

@@ -6,4 +6,4 @@ test_command=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} \
 test_id_option=--load-list $IDFILE
 test_list_option=--list
 # NOTE(chdent): Only used/matches on gabbi-related tests.
-group_regex=(gabbi\.driver\.test_gabbi_[^_]+)_
+group_regex=(gabbi\.driver\.test_gabbi_(?:prefix_|)[^_]+)_

ceilometer/api/controllers/root.py

@@ -27,7 +27,7 @@ class RootController(object):
 
     @pecan.expose('json')
     def index(self):
-        base_url = pecan.request.host_url
+        base_url = pecan.request.application_url
         available = [{'tag': 'v2', 'date': '2013-02-13T00:00:00Z', }]
         collected = [version_descriptor(base_url, v['tag'], v['date'])
                      for v in available]

ceilometer/api/controllers/v2/resources.py

@@ -100,14 +100,14 @@ class ResourcesController(rest.RestController):
                          rel=rel_name)
 
     def _resource_links(self, resource_id, meter_links=1):
-        links = [self._make_link('self', pecan.request.host_url,
+        links = [self._make_link('self', pecan.request.application_url,
                                  'resources', resource_id)]
         if meter_links:
             for meter in pecan.request.storage_conn.get_meters(
                     resource=resource_id):
                 query = {'field': 'resource_id', 'value': resource_id}
                 links.append(self._make_link(meter.name,
-                                             pecan.request.host_url,
+                                             pecan.request.application_url,
                                              'meters', meter.name,
                                              query=query))
         return links

ceilometer/tests/gabbi/gabbits_prefix/api_events_with_data.yaml

@@ -0,0 +1,13 @@
+# This test runs against the Events API and confirms the
+# content-location header includes a prefix.
+fixtures:
+- ConfigFixture
+- EventDataFixture
+
+tests:
+
+- name: get all events
+  url: /v2/events
+  response_headers:
+      content-type: application/json; charset=UTF-8
+      content-location: /$SCHEME://.*/telemetry/v2/events/

ceilometer/tests/gabbi/gabbits_prefix/basic.yaml

@@ -0,0 +1,20 @@
+#
+# Confirm root reports the right data including a prefixed URL
+#
+fixtures:
+    - ConfigFixture
+
+tests:
+
+# Root gives us some information on where to go from here.
+-    name: quick root check
+     url: /
+     response_headers:
+         content-type: application/json; charset=UTF-8
+     response_strings:
+         - '"base": "application/json"'
+     response_json_paths:
+         versions.values.[0].status: stable
+         versions.values.[0].media-types.[0].base: application/json
+     response_strings:
+         - /telemetry/

ceilometer/tests/gabbi/gabbits_prefix/clean-samples.yaml

@@ -0,0 +1,51 @@
+# Post a simple sample and confirm the created resource has
+# reasonable URLs
+fixtures:
+    - ConfigFixture
+
+tests:
+
+# POST one sample and verify its existence.
+
+    - name: post sample for meter
+      desc: post a single sample
+      url: /v2/meters/apples?direct=True
+      method: POST
+      request_headers:
+          content-type: application/json
+      data: |
+        [
+            {
+                "counter_name": "apples",
+                "project_id": "35b17138-b364-4e6a-a131-8f3099c5be68",
+                "user_id": "efd87807-12d2-4b38-9c70-5f5c2ac427ff",
+                "counter_unit": "instance",
+                "counter_volume": 1,
+                "resource_id": "bd9431c1-8d69-4ad3-803a-8d4a6b89fd36",
+                "resource_metadata": {
+                    "name2": "value2",
+                    "name1": "value1"
+                },
+                "counter_type": "gauge"
+            }
+        ]
+
+      response_json_paths:
+          $.[0].counter_name: apples
+      status: 201
+      response_headers:
+          content-type: application/json; charset=UTF-8
+
+    - name: get resources
+      desc: get the resources that exist because of the sample
+      url: /v2/resources
+      response_json_paths:
+          $.[0].metadata.name2: value2
+
+    - name: get resource
+      desc: get just one of those resources via self
+      url: $RESPONSE['$[0].links[0].href']
+      response_json_paths:
+          $.metadata.name2: value2
+      response_strings:
+          - /telemetry/

ceilometer/tests/gabbi/gabbits_prefix/resources-fixtured.yaml

@@ -0,0 +1,24 @@
+#
+# Explore and cover resources API with gabbi tests when there are a
+# small number of pre-existing resources
+#
+
+fixtures:
+    - ConfigFixture
+    - SampleDataFixture
+
+tests:
+
+    - name: list all resources
+      url: /v2/resources
+      response_json_paths:
+          $[0].user_id: farmerjon
+          $[0].links[1].rel: livestock
+      response_strings:
+          - /telemetry/
+
+    - name: get one resource
+      desc: get a resource via the links in the first resource listed above
+      url: $RESPONSE['$[0].links[0].href']
+      response_json_paths:
+          $.resource_id: $RESPONSE['$[0].resource_id']

ceilometer/tests/gabbi/test_gabbi_prefix.py

@@ -0,0 +1,35 @@
+#
+# Copyright 2015 Red Hat. All Rights Reserved.
+#
+# 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.
+
+"""A module to exercise the Ceilometer API with gabbi with a URL prefix"""
+
+import os
+
+from gabbi import driver
+
+from ceilometer.api import app
+from ceilometer.tests.gabbi import fixtures as fixture_module
+
+
+TESTS_DIR = 'gabbits_prefix'
+
+
+def load_tests(loader, tests, pattern):
+    """Provide a TestSuite to the discovery process."""
+    test_dir = os.path.join(os.path.dirname(__file__), TESTS_DIR)
+    return driver.build_tests(test_dir, loader, host=None,
+                              prefix='/telemetry',
+                              intercept=app.VersionSelectorApplication,
+                              fixture_module=fixture_module)