aws-xray-lambda-promise-subsegment

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 occuring.

Usage

Without a parent segment

// 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
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
    }
});