"""Implement Prometheus client."""
# Copyright (C) 2013 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2015 Brad Cowie, Christopher Lorier and Joe Stringer.
# Copyright (C) 2015 Research and Education Advanced Network New Zealand Ltd.
# Copyright (C) 2015--2019 The Contributors
#
# 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 urllib.parse import parse_qs
from os_ken.lib import hub
from pbr.version import VersionInfo
from prometheus_client import Gauge as PromGauge
from prometheus_client import generate_latest, CONTENT_TYPE_LATEST, REGISTRY
# Ryu's WSGI implementation doesn't always set QUERY_STRING
[docs]
def make_wsgi_app(registry):
"""Create a WSGI app which serves the metrics from a registry."""
def prometheus_app(environ, start_response):
query_str = environ.get("QUERY_STRING", "")
params = parse_qs(query_str)
reg = registry
if "name[]" in params:
reg = reg.restricted_registry(params["name[]"])
output = generate_latest(reg)
status = str("200 OK")
headers = [(str("Content-type"), CONTENT_TYPE_LATEST)]
start_response(status, headers)
return [output]
return prometheus_app
[docs]
class PromClient: # pylint: disable=too-few-public-methods
"""Prometheus client."""
REQUIRED_LABELS = ["dp_id", "dp_name"]
_reg = REGISTRY
def __init__(self, reg=None):
if reg is not None:
self._reg = reg
self.version = VersionInfo("faucet").semantic_version().release_string()
self.faucet_version = PromGauge(
"faucet_pbr_version", "Faucet PBR version", ["version"], registry=self._reg
)
self.faucet_version.labels(version=self.version).set(
1
) # pylint: disable=no-member
self.server = None
self.thread = None
[docs]
def start(self, prom_port, prom_addr, use_test_thread=False):
"""Start webserver."""
if not self.server:
app = make_wsgi_app(self._reg)
if use_test_thread:
# pylint: disable=import-outside-toplevel
from wsgiref.simple_server import make_server, WSGIRequestHandler
import threading
class NoLoggingWSGIRequestHandler(WSGIRequestHandler):
"""Don't log requests."""
def log_message(
self, format, *args
): # pylint: disable=redefined-builtin
pass
self.server = make_server(
prom_addr,
int(prom_port),
app,
handler_class=NoLoggingWSGIRequestHandler,
)
self.thread = threading.Thread(target=self.server.serve_forever)
self.thread.daemon = True
self.thread.start()
else:
self.server = hub.WSGIServer((prom_addr, int(prom_port)), app)
self.thread = hub.spawn(self.server.serve_forever)
self.thread.name = "prometheus"