Nest-Jaeger

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Jaeger middleware to request tracing for nestjs application

Required Reading Opentracing

To fully understand Opentracing, it's helpful to be familiar with the OpenTracing project and terminology more specifically.

Required Reading Jaeger

To fully understand Jaeger, it's helpful to be familiar with the Jaeger project and Jaeger Client for Node

Installation

npm i @chankamlam/nest-jaeger -S

Architecture of Jaeger Server

for development for prodution

Build up Jaeger Server Infra locally(development env)

docker run -d -e COLLECTOR_ZIPKIN_HTTP_PORT=9411 -p5775:5775/udp -p6831:6831/udp -p6832:6832/udp \
  -p5778:5778 -p16686:16686 -p14268:14268 -p9411:9411 jaegertracing/all-in-one:latest

Usage

main.ts

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import {JaegerInterceptor} from '@chankamlam/nest-jaeger'
async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  const config = {
    serviceName: 'service1-nest',
    sampler: {
      type: 'const',
      param: 1
    },
    reporter: {
      collectorEndpoint: 'http://localhost:14268/api/traces'
    },
  };                                             // required
  const options = { baggagePrefix: '-Johua-' };  // optional,you can let options={}

  // setup as global interceptor
  app.useGlobalInterceptors(new JaegerInterceptor(config,options));
  await app.listen(3000);
}
bootstrap();

app.useGlobalInterceptors(new JaegerInterceptor(config,options,
(req,res)=>{
  // do something here before request if you want
  req.jaeger.log('info','just for global log')
},
(req,res)=>{
  // do some thing here before response if you want
}));

Controller by using JaegerInterceptor

import { Controller, Get, UseInterceptors } from '@nestjs/common';
import { AppService } from './app.service';
import {JaegerInterceptor} from '@chankamlam/nest-jaeger';

@Controller()
export class AppController {

  @UseInterceptors(JaegerInterceptor)
  @Get('/test')
  test(){
    return 'test'
  }
}

Controller except using JaegerInterceptor when binding JaegerInterceptor globally

import { Controller, Get, UseInterceptors, SetMetadata,Req } from '@nestjs/common';
import { AppService } from './app.service';
import {JaegerInterceptor} from '@chankamlam/nest-jaeger';

@Controller()
export class AppController {

  // will use JaegerInterceptor when binding JaegerInterceptor globally
  // using remote request by jaeger.axios
  @Get('/remoteRequest')
  async remoteRequest(@Req req) {
    const result = await req.jaeger.axios({ url:'xxxxxx', method:'post', data: { key: '1234' }}).then(r=>r.data)
    return result
  }

   // will use JaegerInterceptor when binding JaegerInterceptor globally
  @Get('/test')
  test(@Req req) {
    req.jaeger.setTag(req.jaeger.tags.ERROR,true)
    req.jaeger.log('error', 'err....') // jaeger object is binded after you use JaegerInterceptor globally
    return 'test'
  }

  // will not use JaegerInterceptor
  @SetMetadata('ExceptJaegerInterceptor', true)
  @Get('/except')
  test() {
    return 'test'
  }
}

Lookup Request Tracing

open url http://localhost:16686 , remember to build up the Jager Server locally first

config

for detail, pls look up to Jaeger Client for Node

{
  serviceName: 'string',           // required
  disable: 'boolean',
  sampler: {
    type: 'string',                // required
    param: 'number',               // required
    hostPort: 'string',
    host: 'string',
    port: 'number',
    refreshIntervalMs: 'number'
  },
  reporter: {
    logSpans: 'boolean',
    agentHost: 'string',
    agentPort: 'number',
    collectorEndpoint: 'string',   // required
    username: 'string',
    password: 'string',
    flushIntervalMs: 'number'
  },
  throttler: {
    host: 'string',
    port: 'number',
    refreshIntervalMs: 'number'
  }
}

options

for details, please see Jaeger Client for Node

{
  contextKey: 'string',
  baggagePrefix: 'string',
  metrics: 'object', // a metrics
  logger: 'object',  // a logger
  tags: 'object',    // set of key-value pairs which will be set as process-level tags on the Tracer itself.
  traceId128bit: 'boolean',
  shareRpcSpan: 'boolean',
  debugThrottler: 'boolean',
}

jaeger

jaeger object will bind in req when you do app.use(jaeger(config,options))

{
  // write the log to master span
  log        : function(name, content)

  // setup tag to master span
  setTag     : function(name, value)

  // setup mutiple tags to master span
  addTags    : function({ k1: v1, k2: v2 })

  /*
   * create a new span under parent span,
   * if parentSpan is undefine will create a new one under default master span
   */
  createSpan : function(name, parentSpan?)

  // all defined tags of opentracing which can be used
  tags       : object

  // using it to remote call service if not it will be broken the tracing to next service
  axios      : function(url, options)
}

log

req.jaeger.log('info', '..........')

setTag

const jaeger = req.jaeger
const tags = jaeger

// using defined tags by opentracing
jaeger.setTag(tags.ERROR, true)

// using your customize tag
jaeger.setTag('warning', true)

setTracingTag

const jaeger = req.jaeger
jaeger.setTracingTag('waybill', 'wb-123456')

addTags

const jaeger = req.jaeger
const tags = jaeger

// add mutiple tag one time
jaeger.addTags({ error: true, info: true })

createSpan

// create a sub span under master span
const span = jaeger.createSpan('subSpanName')

// you also can call method of span
span.log('info', 'info......')
span.setTag('info', true)

// remember to call finish() if not there is no record send to jaeger
span.finish();

tags

predefined tag, some come from OpenTracing project

axios

jaeger.axios wrap axios with tracing header, for usage detail pls look up to axios

license

MIT