Package Exports

jaeger-client-middleware

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (jaeger-client-middleware) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

Jaeger Client Middleware for NodeJS

A middleware for NodeJS support jaeger-client-nodejs

NodeJS 10.x recommended

npm i jaeger-client-middleware

Before Setup

This package is a middleware version of jaeger-client-nodejs, without jaeger setup this package has no effect. Please read these references:

Ref:

-- jaeger-client for NodeJS https://github.com/jaegertracing/jaeger-client-node

-- jaeger tracing for local run https://www.jaegertracing.io/docs/1.16/getting-started

-- jaeger tracing for production https://www.jaegertracing.io/docs/1.16/deployment

How to use

1. Create jeager.js file on your project (libs directory recommended)

libs/jaeger.js

const { initTracer } = require('jaeger-client');

const config = {
  serviceName: 'your-service-name': String,
  reporter: {
    name: 'your-service-name-reporter' : String,
    logSpans: true,
    agentHost: 'your-reporter-host': String,
    agentPort: 'your-report-port': Number
  },
  sampler: {
    type: 'your-sampler-type',
    param: 1.0
  }
};

const options = {
  tags: {
    'service': 'your-service-tag': String,
    'version': 'your-service-version': String,
  }
}
module.exports = initTracer(config,options);

example:

import { initTracer } from "jaeger-client";

const config = {
  serviceName: "my-service",
  reporter: {
    name: "my-service-reporter",
    logSpans: true,
    agentHost: process.env.JAEGER_AGENT_HOST || "localhost",
    agentPort: process.env.JAEGER_AGENT_PORT || 6832
  },
  sampler: {
    type: "const",
    param: 1.0
  }
};
const options = {
  tags: {
    service: "my-service",
    version: process.env.npm_package_version || "1.0.0"
  }
};

export default initTracer(config, options);

2. Create Middleware file (middlewares directory recommended)

middlewares/jaeger-middleware.js

const jaeger = require("path-to-libs/jaeger.js");
const JaegerMiddleware = require("jaeger-client-middleware");
const jaegerMiddleware = new JaegerMiddleware(jaeger);
module.exports = jaegerMiddleware;

After created, your structure should look like

├── libs
│   └── jaeger.js
├── middlewares
│   └── jaeger-middleware.js
├── package.json
├── routes
│   └── index.js
├── app.js

3. Use for API

app.js

const jaegerMiddleware = require("path-to-middleware/jaeger-middleware.js");

// assume you are using express
const app = require('express')();
app.use(
  jaegerMiddleware.handleLogBeforeResponse,
  jaegerMiddleware.createSpanAfterReceivedRequest
);

4. Inject request header before sending request

const jaegerMiddleware = require("path-to-middleware/jaeger-middleware.js");
const injectedHeader = jaegerMiddleware.buildHeaderForHTTPRequest(yourHeaderObject)
// now use injected header for your request