opentelemetry-js/packages/opentelemetry-plugin-express

OpenTelemetry Express Instrumentation for Node.js

This module provides automatic instrumentation for express.

For automatic instrumentation see the @opentelemetry/node package.

Installation

npm install --save @opentelemetry/plugin-express

Supported Versions

• ^4.0.0

Usage

OpenTelemetry Express Instrumentation allows the user to automatically collect trace data and export them to their backend of choice, to give observability to distributed systems.

To load a specific plugin (express in this case), specify it in the Node Tracer's configuration.

const { NodeTracerProvider } = require('@opentelemetry/node');

const provider = new NodeTracerProvider({
  plugins: {
    express: {
      enabled: true,
      // You may use a package name or absolute path to the file.
      path: '@opentelemetry/plugin-express',
    }
  }
});

To load all the supported plugins, use below approach. Each plugin is only loaded when the module that it patches is loaded; in other words, there is no computational overhead for listing plugins for unused modules.

const { NodeTracerProvider } = require('@opentelemetry/node');

const provider = new NodeTracerProvider();

See examples/express for a short example.

Express Plugin Options

Express plugin has few options available to choose from. You can set the following:

Options	Type	Description
ignoreLayers	IgnoreMatcher[]	Express plugin will not trace all layers that match.
ignoreLayersType	ExpressLayerType[]	Express plugin will ignore the layers that match based on their type.

For reference, here are the three different layer type:

• router is the name of express.Router()
• middleware
• request_handler is the name for anything thats not a router or a middleware.

Useful links

• For more information on OpenTelemetry, visit: https://opentelemetry.io/
• For more about OpenTelemetry JavaScript: https://github.com/open-telemetry/opentelemetry-js
• For help or feedback on this project, join us on gitter

License

Apache 2.0 - See LICENSE for more information.