feat: Updated Lambda test for OTEL metrics verification

[jsumners-nr]

This PR goes with newrelic/node-newrelic#4166. It updates the lambda-test such that we can use it to verify the New Relic Lambda extension forwards the otlp_payload correctly when the agent harvests. We are able to verify this by installing the agent from the linked branch and adding a debug line to lib/collector/serverless.js at 174:

process._rawDebug('!!! toFlush:', toFlush)

Upon running the container with the correct agent revision and the above debug line, we will see the data is being added correctly.

What is not clear at the moment is if the extension actually does anything with it. I don't have any data in my NR dashboard to indicate that it does at this time.

Note: we must wait to merge this PR until it can be updated with a newrelic version string that includes the required scaffolding.

[bizob2828]

ERROR: failed to build: failed to solve: public.ecr.aws/lambda/nodejs:26: failed to resolve source metadata for public.ecr.aws/lambda/nodejs:26: public.ecr.aws/lambda/nodejs:26: not found

lambda doesn't have support for node 26 yet

[jsumners-nr]

Very strange. That was working last week, just with a "preview release" disclaimer.

[bizob2828]

I'm not sure loading the extension is going to do anything. if so, we need to figure out how to get it to load telemetry, otherwise it's not very useful

[jsumners-nr]

I'm not sure loading the extension is going to do anything. if so, we need to figure out how to get it to load telemetry, otherwise it's not very useful

Before attempting this approach I verified that the image AWS ships fully replicates the hosted Lambda environment and the API provided therein. The extension registers within the Docker container using the exact same API and exact same API registration points.

[bizob2828]

You may want to take a look at their repo https://github.com/newrelic/newrelic-lambda-extension, you may need to set additional env vars to get the extension to load data

[jsumners-nr]

You may want to take a look at their repo newrelic/newrelic-lambda-extension, you may need to set additional env vars to get the extension to load data

I did that last week. The only missing environment variable was the license key. That has been added in this PR.

My statement about the dashboard above includes simply not knowing where to find Lambda data. I assume it would be under the target app's "distributed trace" data, but I never saw anything there. So I figure I'm missing some sort of Lambda whatever.