How to use

[ghost]

Hi

Its been mentioned that pm2 cannot work with prometheus because we cannot run our own code in the master process. So im curious to know how does this work?

I am trying to test this package but struggling to find out how to set it up.

Does this config go in my pm2 ecosystem file?

 "config": {
    "app_name": "api",             //需要拉取监控数据的 APP 名称
    "app_group": "book",           //consul 服务分组 
    "port": 3000,                  //http服务默认端口，提供 /metrics 和 /online 接口
    "reigster_disabled": false,    //是否禁止服务注册到 consul
    "consul_host": "127.0.0.1",    
    "consul_port": "8500",
    "register_mode": "cluster"            // default:cluster   other: worker
  }

--
where should i put this code in my node app

const promClient = require('prom-client')

process.on('message', function (message) {
    if (message.type === 'prom:getMetricsReq') {
        process.send({
            type: 'prom:getMetricsRes',
            data: {
                requestId: message.data.requestId,
                metrics: promClient.register.getMetricsAsJSON()
            }
        })
    }
})

Do i need to declare a new route to get metrics from port 3000/metrics or will this automatically be available ?

[gatispriede]

Documentation is missing only 1 important thing, the collector needs to be triggered:

const collectDefaultMetrics = promClient.collectDefaultMetrics;

collectDefaultMetrics({ timeout: 5000 });

process.on('message', function (message) {
    if (message.type === 'prom:getMetricsReq') {
        process.send({
            type: 'prom:getMetricsRes',
            data: {
                requestId: message.data.requestId,
                metrics: promClient.register.getMetricsAsJSON()
            }
        })
    }
})```
copy this in you main entry file of nodejs at the bottom (not in any routing mechanism)

then setup variables for the tool, for me works:
[PM2] Module pm2-cluster-prometheus restarted
== pm2-cluster-prometheus ==
┌─────────────────────┬───────────┐
│ key                 │ value     │
├─────────────────────┼───────────┤
│ app_name            │ server    │
│ port                │ 3000      │
│ reigster_disabled   │ false     │
│ consul_service_name │ server    │
│ consul_host         │ 127.0.0.1 │
│ consul_port         │ 80        │
│ register_mode       │ worker    │
└─────────────────────┴───────────┘
where the consul_service_name is the name of your app when you run it with pm2
check with `pm2 list`

[Dream-MG]

@gatispriede tried this but getting error
0|pm2-cluster-prometheus | consul register failed Error: not found
0|pm2-cluster-prometheus | at create (/Users/manish.gupta1/.pm2/modules/pm2-cluster-prometheus/node_modules/papi/lib/errors.js:14:5)
0|pm2-cluster-prometheus | at Object.response [as Response] (/.pm2/modules/pm2-cluster-prometheus/node_modules/papi/lib/errors.js:38:15)
0|pm2-cluster-prometheus | at IncomingMessage. (/.pm2/modules/pm2-cluster-prometheus/node_modules/papi/lib/client.js:592:26)
0|pm2-cluster-prometheus | at IncomingMessage.emit (node:events:402:35)
0|pm2-cluster-prometheus | at IncomingMessage.emit (node:domain:475:12)
0|pm2-cluster-prometheus | at endReadableNT (node:internal/streams/readable:1343:12)
0|pm2-cluster-prometheus | at processTicksAndRejections (node:internal/process/task_queues:83:21)

i've changed the consul port and service name to the app name . Do i've to change any other property ?