Prometheus-自定义Node_Exporter

标量（Scalar）：一个浮点型的数字值

标量只有一个数字，没有时序。

需要注意的是，当使用表达式count(http_requests_total)，返回的数据类型，依然是瞬时向量。用户可以通过内置函数scalar()将单个瞬时向量转换为标量。

Prometheus-自定义Exporter-使用flask

#!/usr/bin/python
# -*- coding:utf-8 -*-
from flask import Flask,request,render_template,jsonify,Markup
import json

import logging
log = logging.getLogger('werkzeug')
log.setLevel(logging.ERROR)
#定义一个全局字典
Show_Prometheus_Handler = {

}

app = Flask(__name__)

@app.route('/send_data',methods={'GET','POST'})
def send_data_to_dict():
    if request.method == "GET":
        return "method error,please use post method!"
    else:
        # 向dict里注册
        global Show_Prometheus_Handler

        message = request.data
        #print(request.data)
        message_to_json = json.loads(message)
        metric = message_to_json.get("metric",None)
        type_staus = message_to_json.get("counterType",None)
        value = message_to_json.get("value",None)
        tags = message_to_json.get("tags",None)
        endpoint = message_to_json.get("endpoint",None)
        # 生成字段
        tag_list = []
        for tag in tags.split(","):
            t1,t2 = tag.split("=")
            tag_list.append('{0}="{1}"'.format(t1,t2))
        else:
            tag_list.append('%s="%s"' %("endpoint",endpoint))

        Show_Prometheus_Handler[metric] = '# HELP %s prometheus collected metric.\n# TYPE %s %s\n%s{%s} %s' %(metric,metric,type_staus.lower(),metric,",".join(tag_list),value)
        #print(Show_Prometheus_Handler[metric])

        return "ok"

@app.route('/metrics',methods=['GET','POST'])
def get_metrics():
    if request.method == "GET":
        metric_list = []
        for _,value in Show_Prometheus_Handler.items():
            metric_list.append(value)
        content_msg = Markup('{0}'.format("\n".join(metric_list)))
        return render_template('status.html',content=content_msg), {'Content-Type': 'text/plain; version=0.0.4'}

@app.route("/clean_metrics",methods=["GET","POST"])
def clean_metrics():
    if request.method == "GET":
        global Show_Prometheus_Handler
        Show_Prometheus_Handler = {}
        return "clean_ok"

if __name__ == '__main__':
    app.run("0.0.0.0",port=7777,threaded=True)

　需要注意的点  当Prometheus 出现Navtive Token的时候 需要在返回html的时候 加上 {'Content-Type': 'text/plain; version=0.0.4'}  Prometheus才能正常拉取数据.