77 lines
2.5 KiB
Python
77 lines
2.5 KiB
Python
# 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 abc
|
|
|
|
from flask import Flask
|
|
from oslo_config import cfg
|
|
from oslo_log import log as logging
|
|
|
|
from kuryr_kubernetes import clients
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
CONF = cfg.CONF
|
|
|
|
|
|
class BaseHealthServer(abc.ABC):
|
|
"""Base class of server used to provide readiness and liveness probes."""
|
|
|
|
def __init__(self, app_name, port):
|
|
self.app_name = app_name
|
|
self.port = port
|
|
self.ctx = None
|
|
self.application = Flask(app_name)
|
|
self.application.add_url_rule(
|
|
'/ready', methods=['GET'], view_func=self.readiness_status)
|
|
self.application.add_url_rule(
|
|
'/alive', methods=['GET'], view_func=self.liveness_status)
|
|
|
|
def apply_conn_close(response):
|
|
response.headers['Connection'] = 'close'
|
|
return response
|
|
|
|
self.application.after_request(apply_conn_close)
|
|
|
|
@abc.abstractmethod
|
|
def readiness_status(self):
|
|
raise NotImplementedError()
|
|
|
|
@abc.abstractmethod
|
|
def liveness_status(self):
|
|
raise NotImplementedError()
|
|
|
|
def run(self):
|
|
# Disable obtrusive werkzeug logs.
|
|
logging.getLogger('werkzeug').setLevel(logging.WARNING)
|
|
|
|
address = '::'
|
|
LOG.info('Starting %s health check server on %s:%d.', self.app_name,
|
|
address, self.port)
|
|
try:
|
|
self.application.run(address, self.port)
|
|
except Exception:
|
|
LOG.exception('Failed to start %s health check server.',
|
|
self.app_name)
|
|
raise
|
|
|
|
def verify_k8s_connection(self):
|
|
k8s = clients.get_kubernetes_client()
|
|
try:
|
|
k8s.get('/healthz', json=False, headers={'Connection': 'close'})
|
|
except Exception as e:
|
|
# Not LOG.exception to make sure long message from K8s API is not
|
|
# repeated.
|
|
LOG.error('Exception when trying to reach Kubernetes API: %s.', e)
|
|
return False
|
|
|
|
return True
|