monasca-events-api/monasca_events_api/app/controller/healthchecks.py

63 lines
2.1 KiB
Python

# Copyright 2017 FUJITSU LIMITED
#
# 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.
import collections
import falcon
from monasca_common.rest import utils as rest_utils
from monasca_events_api.app.healthcheck import kafka_check
HealthCheckResult = collections.namedtuple('HealthCheckResult',
['status', 'details'])
class HealthChecks(object):
# response configuration
CACHE_CONTROL = ['must-revalidate', 'no-cache', 'no-store']
# response codes
HEALTHY_CODE_GET = falcon.HTTP_OK
HEALTHY_CODE_HEAD = falcon.HTTP_NO_CONTENT
NOT_HEALTHY_CODE = falcon.HTTP_SERVICE_UNAVAILABLE
def __init__(self):
self._kafka_check = kafka_check.KafkaHealthCheck()
super(HealthChecks, self).__init__()
def on_head(self, req, res):
res.status = self.HEALTHY_CODE_HEAD
res.cache_control = self.CACHE_CONTROL
def on_get(self, req, res):
# at this point we know API is alive, so
# keep up good work and verify kafka status
kafka_result = self._kafka_check.healthcheck()
# in case it'd be unhealthy,
# message will contain error string
status_data = {
'kafka': kafka_result.message
}
# Really simple approach, ideally that should be
# part of monasca-common with some sort of registration of
# healthchecks concept
res.status = (self.HEALTHY_CODE_GET
if kafka_result.healthy else self.NOT_HEALTHY_CODE)
res.cache_control = self.CACHE_CONTROL
res.body = rest_utils.as_json(status_data)