aws-xray-lambda-promise-subsegment

This will wrap an existing promise in a new promise that also creates a new subsegment in aws x-ray. It takes advantage of lambda already having an open trace to add a sub-segment to.

Running locally

If you are running locally an not inside lambda, you will get a warning:

WARNING: Skipping adding subsegment because we are not executing inside of aws lambda

This is because there is no open trace to add a segment to. However, this will allow you to test locally without errors occurring.

Usage

Without a parent segment

You have two options available. For the simplest possible addition use:

// javascript
const addSegment = require("aws-xray-lambda-promise-subsegment").addSegment;
 
const promiseWrappedInSubsegment = addSegment('subSegmentName', promiseOfThingsFactory());

However, if you want to add metadata or annotations, then you'll need the more complex version:

// javascript
const addPromiseSegment = require("aws-xray-lambda-promise-subsegment").addPromiseSegment;
 
const promiseWrappedInSubsegment = addPromiseSegment({
    segmentName: 'subSegmentName',
    promiseFactory: () => promiseOfThingsFactory(),
    metadata: {
        someMetadata1: greatValue,
        someMetadata2: amazingValue
    },
    annotations: {
        annotation1: bestValue,
        annotation2: biglyValue
    }
});

Es6 Syntax

// es6
const { addSegment } = require("aws-xray-lambda-promise-subsegment");
 
const promiseWrappedInSubsegment = addSegment('subSegmentName', promiseOfThingsFactory());

// es6
import { addPromiseSegment } from "aws-xray-lambda-promise-subsegment";
 
const promiseWrappedInSubsegment = addPromiseSegment({
    segmentName: 'subSegmentName',
    promiseFactory: () => promiseOfThingsFactory(),
    metadata: {
        someMetadata1: greatValue,
        someMetadata2: amazingValue
    },
    annotations: {
        annotation1: bestValue,
        annotation2: biglyValue
    }
});

With a parent segment

// javascript
const addPromiseSegment = require("aws-xray-lambda-promise-subsegment").addPromiseSegment;
 
const promiseWrappedInSubsegment = addPromiseSegment({
    segmentName: 'subSegmentName',
    promiseFactory: async (parentSegment) => {
        await doSomeWork();
        await addPromiseSegment({
            segmentName: 'subSegmentName',
            promiseFactory: promiseOfThingsFactory(),
            parentSegment
        });
        await doSomeMoreWork;
    },
    metadata: {
        someMetadata1: greatValue,
        someMetadata2: amazingValue
    },
    annotations: {
        annotation1: bestValue,
        annotation2: biglyValue
    }
});

// es6
import { addPromiseSegment } from "aws-xray-lambda-promise-subsegment";
 
const promiseWrappedInSubsegment = addPromiseSegment({
    segmentName: 'subSegmentName',
    promiseFactory: async (parentSegment) => {
        await doSomeWork();
        await addPromiseSegment({
            segmentName: 'subSegmentName',
            promiseFactory: () => promiseOfThingsFactory(),
            parentSegment
        });
        await doSomeMoreWork;
    },
    metadata: {
        someMetadata1: greatValue,
        someMetadata2: amazingValue
    },
    annotations: {
        annotation1: bestValue,
        annotation2: biglyValue
    }
});

Contributors

A special thanks to everyone who has contributed!

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