Zipkin Instrumentation for Express

Installation

npm add @govtechsg/express-zipkin-instrumentation --save;

Usage

API

Use the following to include the package:

const expressZipkinInstrumentation = require('@govtechsg/express-zipkin-instrumentation');

The expressZipkinInstrumentation variable will be a function that returns the correct middleware. The arguments are:

• :serviceName
• :zipkinHostname
• :options (optional)

:serviceName identifies the current application in the zipkin dashboard.

:zipkinHostname is the hostname for the zipkin server. When this is set to null (the default behaviour if this is not specified), the trace logs will be routed to stdout instead via console.trace.

:options is an object that can contain the following properties:

• :serviceNamePostfix: this will be appended to the :serviceName parameter in dashed-case.

Basic

const server = express();
// ...
const expressZipkinInstrumentation = require('@govtechsg/express-zipkin-instrumentation');
server.use(expressZipkinInstrumentation(
  'service-name',
  'http://zipkin.yourdomain.com',
))

The above will result in a service identified in the Zipkin dashboard as service-name.

Complete

const server = express();
// ...
const expressZipkinInstrumentation = require('@govtechsg/express-zipkin-instrumentation');
server.use(expressZipkinInstrumentation(
  'service-name',
  'http://zipkin.yourdomain.com',
  {
    serviceNamePostfix: 'development'
  }
))

The above will result in a service identified in the Zipkin dashboard as service-name-development.

Development

Testing

Run tests using:

npm run test

Continuous Integration

Environment Variables

The following environment variables have to be set in Travis for the pipeline to work

• GH_USERNAME: GitHub username
• GH_ACCESS_TOKEN: GitHub personal access token
• NPM_REGISTRY_URL: Hostname of NPM registry being used
• NPM_TOKEN: NPM access token
• GIT_ORIGIN_REMOTE_PATH: Path to repository in GitHub

License

This package is licensed under the MIT license.