test python + prometheus

test.py

from prometheus_client import multiprocess
from prometheus_client import generate_latest, CollectorRegistry, CONTENT_TYPE_LATEST, Gauge

from flask import Flask, Response

app = Flask(__name__)

from flask import request
from prometheus_client import Counter, Histogram
import time
import sys

REQUEST_COUNT = Counter(
    'request_count', 'App Request Count',
    ['app_name', 'method', 'endpoint', 'http_status']
)
REQUEST_LATENCY = Histogram('request_latency_seconds', 'Request latency',
    ['app_name', 'endpoint']
)

def start_timer():
    request.start_time = time.time()

def stop_timer(response):
    resp_time = time.time() - request.start_time
    REQUEST_LATENCY.labels('webapp', request.path).observe(resp_time)
    return response

def record_request_data(response):
    REQUEST_COUNT.labels('webapp', request.method, request.path,
            response.status_code).inc()
    return response

def setup_metrics(app):
    app.before_request(start_timer)
    # The order here matters since we want stop_timer
    # to be executed first
    app.after_request(record_request_data)
    app.after_request(stop_timer)

@app.route('/test/')
def test():
    return 'rest'

@app.route('/test1/')
def test1():
    1/0
    return 'rest'

@app.errorhandler(500)
def handle_500(error):
    return str(error), 500

@app.route('/metrics')
def metrics():
    """
    View the metrics sent to prometheus servers.
    """
    registry = CollectorRegistry()
    multiprocess.MultiProcessCollector(registry)
    data = generate_latest(registry)
    print(data)
    response_headers = [
        ('Content-type', CONTENT_TYPE_LATEST),
        ('Content-Length', str(len(data)))
    ]
    return Response(response=data, status=200, headers=response_headers)

if __name__ == '__main__':
    setup_metrics(app)
    app.run()