Source code for faucet.prom_client

"""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"