opentelemetry-instrumentation-egg

This module provides automatic instrumentation for Egg.

For automatic instrumentation see the @opentelemetry/node package.

Since Egg is based on Koa packaging, we also based it on opentelemetry-instrumentation-koa, just adjusting some details and adaptations.

Installation

This instrumentation relies on HTTP calls to also be instrumented. Make sure you install and enable both, otherwise you will not see any spans being exported from the instrumentation.

npm install --save @opentelemetry/instrumentation-http opentelemetry-instrumentation-egg

Supported Versions

^4.20.0

Usage

OpenTelemetry Egg 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 the instrumentation, specify it in the Node Tracer's configuration:

const { NodeTracerProvider } = require('@opentelemetry/node')
const { registerInstrumentations } = require('@opentelemetry/instrumentation')
const { HttpInstrumentation } = require('@opentelemetry/instrumentation-http')
const { EggInstrumentation } = require('opentelemetry-instrumentation-egg')

const provider = new NodeTracerProvider()
provider.register()

registerInstrumentations({
  instrumentations: [
    // Egg instrumentation expects HTTP layer to be instrumented
    new HttpInstrumentation(),
    new EggInstrumentation(),
  ],
})

Egg Instrumentation Options

Egg instrumentation has few options available to choose from. You can set the following:

Options	Type	Example	Description
`ignoreLayers`	`IgnoreMatcher[]`	`[/^\/_internal\//]`	Ignore layers that by match.
`ignoreLayersType`	`KoaLayerType[]`	`['request_handler']`	Ignore layers of specified type.

ignoreLayers accepts an array of elements of types:

string for full match of the path,
RegExp for partial match of the path,
function in the form of (path) => boolean for custom logic.

ignoreLayersType accepts an array of following strings:

router is the name of egg app.Router,
middleware,

By default, we disable the following egg default middlewares:

export const defaultConfig: EggInstrumentationConfig = {
  ignoreLayers: [
    (name: string) => {
      return [
        'middleware - meta',
        'middleware - siteFile',
        'middleware - notfound',
        'middleware - static',
        'middleware - overrideMethod',
        'middleware - session',
        'middleware - i18n',
        'middleware - bodyParser',
        'middleware - securities',
        'middleware - eggLoaderTrace',
      ].includes(name)
    },
  ],
}

Useful links

For more information on OpenTelemetry, visit: https://opentelemetry.io/
For more about OpenTelemetry JavaScript: https://github.com/open-telemetry/opentelemetry-js