Introduce API for aborting introspection

It is not currently possible to stop a running introspection.  This
may be annoying for the operator, considering the amount of time it
takes for the bare metal node to call the continue API request,
especially knowing the introspection will fail/time-out eventually
(such as when debugging).

This patch introduces a REST API endpoint "POST
/v1/introspection/<node-UUID>/abort" in order to fill the gap.  Upon the
abort method call, following preconditions are checked:

* there's a bare metal node matching the UUID
* introspection was not finished for the node
* introspection process is waiting for the node to give the continue call

Following Responses are returned to the caller in case the
preconditions were not met:

* 404 Response in case node wasn't found
* 409 Response (resource busy) in case the introspection process is not
      waiting for the Continue call

Otherwise, a 202 Response is returned.

When the abort method is processed, the node is powered off and it is
black-listed in inspector's firewall to prevent it from booting the
introspection image. This happens asynchronously.

To prevent interference with the continue call processing, the
processing method was updated to give a 400 Response to the
introspection client in case continuing a finished or canceled
introspection.

Limitations:
* IMPI credentials are never updated in case introspection was canceled
* 202 response is returned even if the introspection was already finished
* the endpoint differs from requested "DELETE
  /v1/introspection/<node-UUID>"

Links:
[1] https://bugs.launchpad.net/ironic-inspector/+bug/1525235

Change-Id: If043171f0d292ae2775dc1f26233dd4911599247
Closes-Bug: #1525235

doc/source/http-api.rst

@@ -51,7 +51,25 @@ Response body: JSON dictionary with keys:
 
 * ``finished`` (boolean) whether introspection is finished
   (``true`` on introspection completion or if it ends because of an error)
-* ``error`` error string or ``null``
+* ``error`` error string or ``null``; ``Canceled by operator`` in
+  case introspection was aborted
+
+
+Abort Running Introspection
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+``POST /v1/introspection/<UUID>/abort`` abort running introspection.
+
+Requires X-Auth-Token header with Keystone token for authentication.
+
+Response:
+
+* 202 - accepted
+* 400 - bad request
+* 401, 403 - missing or invalid authentication
+* 404 - node cannot be found
+* 409 - inspector has locked this node for processing
+
 
 Get Introspection Data
 ~~~~~~~~~~~~~~~~~~~~~~
@@ -295,3 +313,4 @@ Version History
 * **1.0** version of API at the moment of introducing versioning.
 * **1.1** adds endpoint to retrieve stored introspection data.
 * **1.2** endpoints for manipulating introspection rules.
+* **1.3** endpoint for canceling running introspection

ironic_inspector/introspect.py

@@ -174,3 +174,54 @@ def _background_introspect_locked(ironic, node_info):
         LOG.info(_LI('Introspection environment is ready, manual power on is '
                      'required within %d seconds'), CONF.timeout,
                  node_info=node_info)
+
+
+def abort(uuid, token=None):
+    """Abort running introspection.
+
+    :param uuid: node uuid
+    :param token: authentication token
+    :raises: Error
+    """
+    LOG.debug('Aborting introspection for node %s', uuid)
+    ironic = utils.get_client(token)
+    node_info = node_cache.get_node(uuid, ironic=ironic, locked=False)
+
+    # check pending operations
+    locked = node_info.acquire_lock(blocking=False)
+    if not locked:
+        # Node busy --- cannot abort atm
+        raise utils.Error(_('Node is locked, please, retry later'),
+                          node_info=node_info, code=409)
+
+    utils.spawn_n(_abort, node_info, ironic)
+
+
+def _abort(node_info, ironic):
+    # runs in background
+    if node_info.finished_at is not None:
+        # introspection already finished; nothing to do
+        LOG.info(_LI('Cannot abort introspection as it is already '
+                     'finished'), node_info=node_info)
+        node_info.release_lock()
+        return
+
+    # block this node from PXE Booting the introspection image
+    try:
+        firewall.update_filters(ironic)
+    except Exception as exc:
+        # Note(mkovacik): this will be retried in firewall update
+        # periodic task; we continue aborting
+        LOG.warning(_LW('Failed to update firewall filters: %s'), exc,
+                    node_info=node_info)
+
+    # finish the introspection
+    LOG.debug('Forcing power-off', node_info=node_info)
+    try:
+        ironic.node.set_power_state(node_info.uuid, 'off')
+    except Exception as exc:
+        LOG.warning(_LW('Failed to power off node: %s'), exc,
+                    node_info=node_info)
+
+    node_info.finished(error=_('Canceled by operator'))
+    LOG.info(_LI('Introspection aborted'), node_info=node_info)

ironic_inspector/main.py

@@ -45,7 +45,7 @@ app = flask.Flask(__name__)
 LOG = utils.getProcessingLogger(__name__)
 
 MINIMUM_API_VERSION = (1, 0)
-CURRENT_API_VERSION = (1, 2)
+CURRENT_API_VERSION = (1, 3)
 _MIN_VERSION_HEADER = 'X-OpenStack-Ironic-Inspector-API-Minimum-Version'
 _MAX_VERSION_HEADER = 'X-OpenStack-Ironic-Inspector-API-Maximum-Version'
 _VERSION_HEADER = 'X-OpenStack-Ironic-Inspector-API-Version'
@@ -209,6 +209,18 @@ def api_introspection(uuid):
                                   error=node_info.error or None)
 
 
+@app.route('/v1/introspection/<uuid>/abort', methods=['POST'])
+@convert_exceptions
+def api_introspection_abort(uuid):
+    utils.check_auth(flask.request)
+
+    if not uuidutils.is_uuid_like(uuid):
+        raise utils.Error(_('Invalid UUID value'), code=400)
+
+    introspect.abort(uuid, token=flask.request.headers.get('X-Auth-Token'))
+    return '', 202
+
+
 @app.route('/v1/introspection/<uuid>/data', methods=['GET'])
 @convert_exceptions
 def api_introspection_data(uuid):

ironic_inspector/process.py

@@ -104,6 +104,12 @@ def process(introspection_data):
     LOG.info(_LI('Matching node is %s'), node_info.uuid,
              node_info=node_info, data=introspection_data)
 
+    if node_info.finished_at is not None:
+        # race condition or introspection canceled
+        raise utils.Error(_('Node processing already finished with '
+                            'error: %s') % node_info.error,
+                          node_info=node_info, code=400)
+
     try:
         node = node_info.node()
     except exceptions.NotFound:

ironic_inspector/test/functional.py

@@ -159,6 +159,9 @@ class Base(base.NodeTest):
     def call_get_status(self, uuid):
         return self.call('get', '/v1/introspection/%s' % uuid).json()
 
+    def call_abort_introspect(self, uuid):
+        return self.call('post', '/v1/introspection/%s/abort' % uuid)
+
     def call_continue(self, data):
         return self.call('post', '/v1/continue', data=data).json()
 
@@ -361,6 +364,30 @@ class Test(Base):
         status = self.call_get_status(self.uuid)
         self.assertEqual({'finished': True, 'error': None}, status)
 
+    def test_abort_introspection(self):
+        self.call_introspect(self.uuid)
+        eventlet.greenthread.sleep(DEFAULT_SLEEP)
+        self.cli.node.set_power_state.assert_called_once_with(self.uuid,
+                                                              'reboot')
+        status = self.call_get_status(self.uuid)
+        self.assertEqual({'finished': False, 'error': None}, status)
+
+        res = self.call_abort_introspect(self.uuid)
+        eventlet.greenthread.sleep(DEFAULT_SLEEP)
+
+        self.assertEqual(res.status_code, 202)
+        status = self.call_get_status(self.uuid)
+        self.assertTrue(status['finished'])
+        self.assertEqual('Canceled by operator', status['error'])
+
+        # Note(mkovacik): we're checking just this doesn't pass OK as
+        # there might be either a race condition (hard to test) that
+        # yields a 'Node already finished.' or an attribute-based
+        # look-up error from some pre-processing hooks because
+        # node_info.finished() deletes the look-up attributes only
+        # after releasing the node lock
+        self.call('post', '/v1/continue', self.data, expect_error=400)
+
 
 @contextlib.contextmanager
 def mocked_server():

ironic_inspector/test/test_introspect.py

@@ -416,3 +416,109 @@ class TestSetIpmiCredentials(BaseTest):
 
         self.assertRaises(utils.Error, introspect.introspect, self.uuid,
                           new_ipmi_credentials=self.new_creds)
+
+
+@mock.patch.object(utils, 'spawn_n',
+                   lambda f, *a, **kw: f(*a, **kw) and None)
+@mock.patch.object(firewall, 'update_filters', autospec=True)
+@mock.patch.object(node_cache, 'get_node', autospec=True)
+@mock.patch.object(utils, 'get_client', autospec=True)
+class TestAbort(BaseTest):
+    def setUp(self):
+        super(TestAbort, self).setUp()
+        self.node_info.started_at = None
+        self.node_info.finished_at = None
+
+    def test_ok(self, client_mock, get_mock, filters_mock):
+        cli = self._prepare(client_mock)
+        get_mock.return_value = self.node_info
+        self.node_info.acquire_lock.return_value = True
+        self.node_info.started_at = time.time()
+        self.node_info.finished_at = None
+
+        introspect.abort(self.node.uuid)
+
+        get_mock.assert_called_once_with(self.uuid, ironic=cli,
+                                         locked=False)
+        self.node_info.acquire_lock.assert_called_once_with(blocking=False)
+        filters_mock.assert_called_once_with(cli)
+        cli.node.set_power_state.assert_called_once_with(self.uuid, 'off')
+        self.node_info.finished.assert_called_once_with(error='Canceled '
+                                                        'by operator')
+
+    def test_node_not_found(self, client_mock, get_mock, filters_mock):
+        cli = self._prepare(client_mock)
+        exc = utils.Error('Not found.', code=404)
+        get_mock.side_effect = iter([exc])
+
+        self.assertRaisesRegexp(utils.Error, str(exc),
+                                introspect.abort, self.uuid)
+
+        self.assertEqual(0, filters_mock.call_count)
+        self.assertEqual(0, cli.node.set_power_state.call_count)
+        self.assertEqual(0, self.node_info.finished.call_count)
+
+    def test_node_locked(self, client_mock, get_mock, filters_mock):
+        cli = self._prepare(client_mock)
+        get_mock.return_value = self.node_info
+        self.node_info.acquire_lock.return_value = False
+        self.node_info.started_at = time.time()
+
+        self.assertRaisesRegexp(utils.Error, 'Node is locked, please, '
+                                'retry later', introspect.abort, self.uuid)
+
+        self.assertEqual(0, filters_mock.call_count)
+        self.assertEqual(0, cli.node.set_power_state.call_count)
+        self.assertEqual(0, self.node_info.finshed.call_count)
+
+    def test_introspection_already_finished(self, client_mock,
+                                            get_mock, filters_mock):
+        cli = self._prepare(client_mock)
+        get_mock.return_value = self.node_info
+        self.node_info.acquire_lock.return_value = True
+        self.node_info.started_at = time.time()
+        self.node_info.finished_at = time.time()
+
+        introspect.abort(self.uuid)
+
+        self.assertEqual(0, filters_mock.call_count)
+        self.assertEqual(0, cli.node.set_power_state.call_count)
+        self.assertEqual(0, self.node_info.finshed.call_count)
+
+    def test_firewall_update_exception(self, client_mock, get_mock,
+                                       filters_mock):
+        cli = self._prepare(client_mock)
+        get_mock.return_value = self.node_info
+        self.node_info.acquire_lock.return_value = True
+        self.node_info.started_at = time.time()
+        self.node_info.finished_at = None
+        filters_mock.side_effect = iter([Exception('Boom')])
+
+        introspect.abort(self.uuid)
+
+        get_mock.assert_called_once_with(self.uuid, ironic=cli,
+                                         locked=False)
+        self.node_info.acquire_lock.assert_called_once_with(blocking=False)
+        filters_mock.assert_called_once_with(cli)
+        cli.node.set_power_state.assert_called_once_with(self.uuid, 'off')
+        self.node_info.finished.assert_called_once_with(error='Canceled '
+                                                        'by operator')
+
+    def test_node_power_off_exception(self, client_mock, get_mock,
+                                      filters_mock):
+        cli = self._prepare(client_mock)
+        get_mock.return_value = self.node_info
+        self.node_info.acquire_lock.return_value = True
+        self.node_info.started_at = time.time()
+        self.node_info.finished_at = None
+        cli.node.set_power_state.side_effect = iter([Exception('BadaBoom')])
+
+        introspect.abort(self.uuid)
+
+        get_mock.assert_called_once_with(self.uuid, ironic=cli,
+                                         locked=False)
+        self.node_info.acquire_lock.assert_called_once_with(blocking=False)
+        filters_mock.assert_called_once_with(cli)
+        cli.node.set_power_state.assert_called_once_with(self.uuid, 'off')
+        self.node_info.finished.assert_called_once_with(error='Canceled '
+                                                        'by operator')

ironic_inspector/test/test_main.py

@@ -135,6 +135,50 @@ class TestApiContinue(BaseAPITest):
         self.assertFalse(process_mock.called)
 
 
+@mock.patch.object(introspect, 'abort', autospec=True)
+class TestApiAbort(BaseAPITest):
+    def test_ok(self, abort_mock):
+        abort_mock.return_value = '', 202
+
+        res = self.app.post('/v1/introspection/%s/abort' % self.uuid,
+                            headers={'X-Auth-Token': 'token'})
+
+        abort_mock.assert_called_once_with(self.uuid, token='token')
+        self.assertEqual(202, res.status_code)
+        self.assertEqual(b'', res.data)
+
+    def test_no_authentication(self, abort_mock):
+        abort_mock.return_value = b'', 202
+
+        res = self.app.post('/v1/introspection/%s/abort' % self.uuid)
+
+        abort_mock.assert_called_once_with(self.uuid, token=None)
+        self.assertEqual(202, res.status_code)
+        self.assertEqual(b'', res.data)
+
+    def test_node_not_found(self, abort_mock):
+        exc = utils.Error("Not Found.", code=404)
+        abort_mock.side_effect = iter([exc])
+
+        res = self.app.post('/v1/introspection/%s/abort' % self.uuid)
+
+        abort_mock.assert_called_once_with(self.uuid, token=None)
+        self.assertEqual(404, res.status_code)
+        data = json.loads(str(res.data.decode()))
+        self.assertEqual(str(exc), data['error']['message'])
+
+    def test_abort_failed(self, abort_mock):
+        exc = utils.Error("Locked.", code=409)
+        abort_mock.side_effect = iter([exc])
+
+        res = self.app.post('/v1/introspection/%s/abort' % self.uuid)
+
+        abort_mock.assert_called_once_with(self.uuid, token=None)
+        self.assertEqual(409, res.status_code)
+        data = json.loads(res.data.decode())
+        self.assertEqual(str(exc), data['error']['message'])
+
+
 class TestApiGetStatus(BaseAPITest):
     @mock.patch.object(node_cache, 'get_node', autospec=True)
     def test_get_introspection_in_progress(self, get_mock):

ironic_inspector/test/test_process.py

@@ -127,6 +127,18 @@ class TestProcess(BaseTest):
         self.assertFalse(process_mock.called)
         pop_mock.return_value.finished.assert_called_once_with(error=mock.ANY)
 
+    @prepare_mocks
+    def test_already_finished(self, cli, pop_mock, process_mock):
+        old_finished_at = pop_mock.return_value.finished_at
+        pop_mock.return_value.finished_at = time.time()
+        try:
+            self.assertRaisesRegexp(utils.Error, 'already finished',
+                                    process.process, self.data)
+            self.assertFalse(process_mock.called)
+            self.assertFalse(pop_mock.return_value.finished.called)
+        finally:
+            pop_mock.return_value.finished_at = old_finished_at
+
     @prepare_mocks
     def test_expected_exception(self, cli, pop_mock, process_mock):
         process_mock.side_effect = iter([utils.Error('boom')])

releasenotes/notes/abort-introspection-ae5cb5a9fbacd2ac.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - Introduced API "POST /v1/introspection/<UUID>/abort" for aborting
+    the introspection process.