Merge "Add optional healthcheck middleware"

ironic/api/app.py

@@ -18,6 +18,7 @@
 import keystonemiddleware.audit as audit_middleware
 from oslo_config import cfg
 import oslo_middleware.cors as cors_middleware
+from oslo_middleware import healthcheck
 import osprofiler.web as osprofiler_web
 import pecan
 
@@ -103,6 +104,14 @@ def setup_app(pecan_config=None, extra_hooks=None):
     if CONF.profiler.enabled:
         app = osprofiler_web.WsgiMiddleware(app)
 
+    # add in the healthcheck middleware if enabled
+    # NOTE(jroll) this is after the auth token middleware as we don't want auth
+    # in front of this, and WSGI works from the outside in. Requests to
+    # /healthcheck will be handled and returned before the auth middleware
+    # is reached.
+    if CONF.healthcheck.enabled:
+        app = healthcheck.Healthcheck(app, CONF)
+
     # Create a CORS wrapper, and attach ironic-specific defaults that must be
     # included in all CORS responses.
     app = IronicCORS(app, CONF)

ironic/conf/__init__.py

@@ -29,6 +29,7 @@ from ironic.conf import deploy
 from ironic.conf import dhcp
 from ironic.conf import drac
 from ironic.conf import glance
+from ironic.conf import healthcheck
 from ironic.conf import ilo
 from ironic.conf import inspector
 from ironic.conf import ipmi
@@ -62,6 +63,7 @@ deploy.register_opts(CONF)
 drac.register_opts(CONF)
 dhcp.register_opts(CONF)
 glance.register_opts(CONF)
+healthcheck.register_opts(CONF)
 ilo.register_opts(CONF)
 inspector.register_opts(CONF)
 ipmi.register_opts(CONF)

ironic/conf/healthcheck.py

@@ -0,0 +1,29 @@
+#    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
+
+from ironic.common.i18n import _
+
+opts = [
+    cfg.BoolOpt('enabled',
+                default=False,
+                help=_('Enable the health check endpoint at /healthcheck. '
+                       'Note that this is unauthenticated. More information '
+                       'is available at '
+                       'https://docs.openstack.org/oslo.middleware/latest/'
+                       'reference/healthcheck_plugins.html.')),
+]
+
+
+def register_opts(conf):
+    conf.register_opts(opts, group='healthcheck')

ironic/conf/opts.py

@@ -47,6 +47,7 @@ _opts = [
     ('dhcp', ironic.conf.dhcp.opts),
     ('drac', ironic.conf.drac.opts),
     ('glance', ironic.conf.glance.list_opts()),
+    ('healthcheck', ironic.conf.healthcheck.opts),
     ('ilo', ironic.conf.ilo.opts),
     ('inspector', ironic.conf.inspector.list_opts()),
     ('ipmi', ironic.conf.ipmi.opts),

ironic/tests/unit/api/test_healthcheck.py

@@ -0,0 +1,39 @@
+#    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.
+"""
+Tests to assert that audit middleware works as expected.
+"""
+
+import mock
+from oslo_config import cfg
+from oslo_middleware import healthcheck
+
+from ironic.tests.unit.api import base
+
+
+CONF = cfg.CONF
+
+
+class TestHealthcheckMiddleware(base.BaseApiTest):
+    """Provide a basic smoke test to ensure healthcheck middleware works."""
+
+    @mock.patch.object(healthcheck, 'Healthcheck')
+    def test_enable(self, mock_healthcheck):
+        CONF.set_override('enabled', True, group='healthcheck')
+        self._make_app()
+        mock_healthcheck.assert_called_once_with(mock.ANY, CONF)
+
+    @mock.patch.object(healthcheck, 'Healthcheck')
+    def test_disable(self, mock_healthcheck):
+        CONF.set_override('enabled', False, group='healthcheck')
+        self._make_app()
+        self.assertFalse(mock_healthcheck.called)

releasenotes/notes/add-healthcheck-middleware-86120fa07a7c8151.yaml

@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    Adds the healthcheck middleware from oslo, configurable via the
+    ``[healthcheck]/enabled`` option. This middleware adds a status check at
+    `/healthcheck`. This is useful for load balancers to determine if a service
+    is up (and add or remove it from rotation), or for monitoring tools to see
+    the health of the server. This endpoint is unauthenticated, as not all load
+    balancers or monitoring tools support authenticating with a health check
+    endpoint.

tools/config/ironic-config-generator.conf

@@ -10,6 +10,7 @@ namespace = ironic_lib.utils
 namespace = oslo.db
 namespace = oslo.messaging
 namespace = oslo.middleware.cors
+namespace = oslo.middleware.healthcheck
 namespace = oslo.concurrency
 namespace = oslo.policy
 namespace = oslo.log