Cdk lambda Typescript OTEL Honeycomb

Blog post explaining this project

Purpose:

This project is meant to demonstrate how to export (automatic + manual) traces from lambda to honeycomb. The reason we cannot just use standard library (@opentelemetry/api) / exporter (and why we must use a layer) is because lambda does not flush the traces after an invoke. This will lead to missing telemetry data.

Why does this demo project exist?

Getting AWS' Lambda layer to work CDK + Honeycomb is hard.

1. CDK uses ESbuild -- OTel's auto-instrumentation requires certain values be modifiable / be layed out a particular way
2. The aws-otel-lambda works best with XRay
3. Honeycomb recommends aws-otel-lambda, but does not provide a detailed guide on how to set it up

Set-up demo project

1. Copy + Paste collector-template.yaml to collector.yaml
2. Replace xxx in collector.yaml to your honeycomb keys
3. npm install -- Installs dependencies
4. npx cdk deploy -- Deploys the stack NOTE: Must use us-east-1 as this is where the lambda layer is
5. Hit the URL that CDK outputs from the deployment. You should see a counter
6. Review honeycomb, your traces should be present

How to use this demo

This demo project is a reference for the simplest possible set up. Review the /lib directory for changes you will need to make to your application.

Additional benefits to the project

• Provides a TYPED decorator style function (spanify) to reduce nesting from startActiveSpan
  • Spanify provides a sane default exception handling
• Adds TS typing back to the @opentelemetry/api methods

Todo improvements to the project

• Push traces to honeycomb when lambda code is run locally (this will require a different codepath that calls a local version of @opentelemetry/api)
• Remove us-east-1 from the layer and pull the region from CDK