Provide a gabbi-tempest job, tested by itself

The name follows the patterns defined by zuul docs.
The Depends-On is to a necessary Tempest change for
handling the enviornment variable.

The gabbigts in gate/gabbits talk to keystone and nova
to simply confirm that the tests can run.

Depends-On: https://review.openstack.org/607507
Change-Id: I7a9efefb28e23bf47951617cbe08f177235688d6

.zuul.yaml

@@ -1,3 +1,25 @@
 - project:
-    templates:
-      - noop-jobs
+    check:
+      jobs:
+        - gabbi-tempest
+    gate:
+      jobs:
+        - gabbi-tempest
+
+- job:
+    name: gabbi-tempest
+    parent: devstack-tempest
+    description: |
+      A job that can be used as a base for running gabbi tests
+      against a set of directories.
+    required-projects:
+      - openstack/gabbi-tempest
+    vars:
+      gabbi_tempest_path: "{{ devstack_base_dir|default('/opt/stack') }}/gabbi-tempest/gate/gabbits"
+      tox_envlist: all
+      tempest_test_regex: 'gabbi'
+      # run test in serial, because we have no control over stestr group_regex
+      tempest_concurrency: 1
+      devstack_localrc:
+        TEMPEST_PLUGINS: "{{ devstack_base_dir|default('/opt/stack') }}/gabbi-tempest"
+        USE_PYTHON3: True

gate/gabbits/confirm.yaml

@@ -0,0 +1,27 @@
+# A basic set of tests to confirm that we the test environment and plugin
+# system is working as expected. We retrieve some information from keystone
+# and then confirm it against nova.
+
+defaults:
+    request_headers:
+        x-auth-token: $ENVIRON['SERVICE_TOKEN']
+        content-type: application/json
+        accept: application/json
+
+tests:
+
+    - name: retrieve services
+      GET: $ENVIRON['IDENTITY_SERVICE']/v3/services
+      response_json_paths:
+          $.services[?type = compute].name: nova
+
+    - name: retrieve compute endpoint
+      GET: $ENVIRON['IDENTITY_SERVICE']/v3/endpoints?interface=public&service_id=$RESPONSE['$.services[?type = compute].id']
+      response_json_paths:
+          $.endpoints[0].url: $ENVIRON['COMPUTE_SERVICE']
+
+    - name: get compute version doc
+      GET: $RESPONSE['$.endpoints[0].url']
+      redirects: True
+      response_json_paths:
+          $.version.status: CURRENT