PROMETHEUS

• It is an monitoring tool for metrics

• We have to setup prometheus into our code because it is self hosted

• Does not have agents same as Newrelic

• Install prom-client

  npm i prom-client

• Collect default metrics of server by adding this into main index.js

  const collectDefaultMetrics = promClient.collectDefaultMetrics;

• Register the collected metrics

  collectDefaultMetrics({register:promClient.register});

• Create api route to provide all collected metrics

app.get('/metrics',async(req,res)=>{
  //we had set the content type into headers
 res.setHeader('Content-Type',promClient.register.contentType);
 //get the metrics from promp client
 const metrics = await promClient.register.metrics();
 //return the metrics in reponse
 res.send(metrics);
})

• Create prometheus-config.yml file and put the bellow data init

global:
 scrape_interval: 4s #scrap the data after every 4 seconds

scrape_configs:
 -job_name: prometheus
  static_configs:
    -targets: [" 192.168.1.16:8000"] #from this local-host/ourIPaddress:port

• Create docker-compose.yaml for prometheus server

version: "3"

services:
  prom-server:
   image: prom/prometheus
   ports:
     - 9090:9090
   volumes:
     - ./prometheus-config.yml:/etc/prometheus/prometheus.yaml

GRAFANA

• It is used for metrics-visualization

• It uses the metrics which was scrapped by prometheus server

• It integrate the prometheus into its service

• To run the grafana image directly into docker from CLI

docker run -d -p 3000:3000 --name=grafana grafana/grafana-oss

• To run from docker-compose

  grafana:
    image: grafana/grafana-oss
    container_name: grafana
    ports:
      - 3000:3000
    restart: always