使用Python编写Prometheus监控的方法

要使用python编写Prometheus监控，需要你先开启Prometheus集群。可以参考//www.jb51.net/article/148895.htm 安装。在python中实现服务器端。在Prometheus中配置请求网址，Prometheus会定期向该网址发起申请获取你想要返回的数据。

使用Python和Flask编写Prometheus监控

Installation

pip install flask
pip install prometheus_client

Metrics

Prometheus提供4种类型Metrics：Counter, Gauge, Summary和Histogram

Counter

Counter可以增长，并且在程序重启的时候会被重设为0，常被用于任务个数，总处理时间，错误个数等只增不减的指标。

import prometheus_client
from prometheus_client import Counter
from prometheus_client.core import CollectorRegistry
from flask import Response, Flask
app = Flask(__name__)
requests_total = Counter("request_count", "Total request cout of the host")
@app.route("/metrics")
def requests_count():
  requests_total.inc()
  # requests_total.inc(2)
  return Response(prometheus_client.generate_latest(requests_total),
          mimetype="text/plain")
@app.route('/')
def index():
  requests_total.inc()
  return "Hello World"
if __name__ == "__main__":
  app.run(host="0.0.0.0")

运行该脚本，访问youhost:5000/metrics

# HELP request_count Total request cout of the host
# TYPE request_count counter
request_count 3.0

Gauge

Gauge与Counter类似，唯一不同的是Gauge数值可以减少，常被用于温度、利用率等指标。

import random
import prometheus_client
from prometheus_client import Gauge
from flask import Response, Flask
app = Flask(__name__)
random_value = Gauge("random_value", "Random value of the request")
@app.route("/metrics")
def r_value():
  random_value.set(random.randint(0, 10))
  return Response(prometheus_client.generate_latest(random_value),
          mimetype="text/plain")
if __name__ == "__main__":
  app.run(host="0.0.0.0")

运行该脚本，访问youhost:5000/metrics

# HELP random_value Random value of the request
# TYPE random_value gauge
random_value 3.0

Summary/Histogram

Summary/Histogram概念比较复杂，一般exporter很难用到，暂且不说。

LABELS

使用labels来区分metric的特征

from prometheus_client import Counter
c = Counter('requests_total', 'HTTP requests total', ['method', 'clientip'])
c.labels('get', '127.0.0.1').inc()
c.labels('post', '192.168.0.1').inc(3)
c.labels(method="get", clientip="192.168.0.1").inc()

使用Python和asyncio编写Prometheus监控

from prometheus_client import Counter, Gauge
from prometheus_client.core import CollectorRegistry
REGISTRY = CollectorRegistry(auto_describe=False)
requests_total = Counter("request_count", "Total request cout of the host", registry=REGISTRY)
random_value = Gauge("random_value", "Random value of the request", registry=REGISTRY)

import prometheus_client
from prometheus_client import Counter,Gauge
from prometheus_client.core import CollectorRegistry
from aiohttp import web
import aiohttp
import asyncio
import uvloop
import random,logging,time,datetime
asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
routes = web.RouteTableDef()
# metrics包含
requests_total = Counter("request_count", "Total request cout of the host") # 数值只增
random_value = Gauge("random_value", "Random value of the request") # 数值可大可小
@routes.get('/metrics')
async def metrics(request):
  requests_total.inc()   # 计数器自增
  # requests_total.inc(2)
  data = prometheus_client.generate_latest(requests_total)
  return web.Response(body = data,content_type="text/plain")  # 将计数器的值返回
@routes.get("/metrics2")
async def metrics2(request):
  random_value.set(random.randint(0, 10))  # 设置值任意值，但是一定要为 整数或者浮点数
  return web.Response(body = prometheus_client.generate_latest(random_value),content_type="text/plain")  # 将值返回
@routes.get('/')
async def hello(request):
  return web.Response(text="Hello, world")
# 使用labels来区分metric的特征
c = Counter('requests_total', 'HTTP requests total', ['method', 'clientip']) # 添加lable的key，
c.labels('get', '127.0.0.1').inc()    #为不同的label进行统计
c.labels('post', '192.168.0.1').inc(3)   #为不同的label进行统计
c.labels(method="get", clientip="192.168.0.1").inc()  #为不同的label进行统计
g = Gauge('my_inprogress_requests', 'Description of gauge',['mylabelname'])
g.labels(mylabelname='str').set(3.6)  #value自己定义,但是一定要为 整数或者浮点数
if __name__ == '__main__':
  logging.info('server start：%s'% datetime.datetime.now())
  app = web.Application(client_max_size=int(2)*1024**2)  # 创建app，设置最大接收图片大小为2M
  app.add_routes(routes)   # 添加路由映射
  web.run_app(app,host='0.0.0.0',port=2222)  # 启动app
  logging.info('server close：%s'% datetime.datetime.now())