Incorrect instructions in README for `@sentry/serverless` Lambda Layer

[tessro]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which package are you using?

@sentry/serverless

SDK Version

Lambda Layer 87 (v7.18.0?)

Framework Version

No response

Link to Sentry event

No response

Steps to Reproduce

Follow steps from here: https://github.com/getsentry/sentry-javascript/tree/master/packages/serverless

Integrate Sentry using internal extension

Another and much simpler way to integrate Sentry to your AWS Lambda function is to add an official layer.

1. Choose Layers -> Add Layer.
2. Specify an ARN: arn:aws:lambda:us-west-1:TODO:layer:TODO:VERSION.
3. Go to Environment variables and add:
   • NODE_OPTIONS: -r @sentry/serverless/cjs/awslambda-auto.
   • SENTRY_DSN: your dsn.
   • SENTRY_TRACES_SAMPLE_RATE: a number between 0 and 1 representing the chance a transaction is sent to Sentry. For more information, see docs.

Expected Result

Sentry initializes correctly.

Actual Result

Runtime error during execution:

Error: Cannot find module '@sentry/serverless/cjs/awslambda-auto'

Require stack:
- internal/preload

at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
at Function.Module._load (node:internal/modules/cjs/loader:778:27)
at Module.require (node:internal/modules/cjs/loader:1005:19)
at Module._preloadModules (node:internal/modules/cjs/loader:1282:12)
at loadPreloadModules (node:internal/bootstrap/pre_execution:539:5)
at prepareMainThreadExecution (node:internal/bootstrap/pre_execution:85:3)
at node:internal/main/run_main_module:7:1 {
  code: 'MODULE_NOT_FOUND',
  node:internal/modules/cjs/loader:936
}

I downloaded and inspected the layer, its contents are:

Archive:  sentry.zip
   creating: relay/
  inflating: relay/relay
   creating: extensions/
  inflating: extensions/sentry-lambda-extension
   creating: nodejs/
   creating: nodejs/node_modules/
   creating: nodejs/node_modules/@sentry/
   creating: nodejs/node_modules/@sentry/serverless/
  inflating: nodejs/node_modules/@sentry/serverless/package.json
   creating: nodejs/node_modules/@sentry/serverless/dist/
    linking: nodejs/node_modules/@sentry/serverless/dist/awslambda-auto.js  -> ../build/npm/cjs/awslambda-auto.js
   creating: nodejs/node_modules/@sentry/serverless/build/
   creating: nodejs/node_modules/@sentry/serverless/build/npm/
   creating: nodejs/node_modules/@sentry/serverless/build/npm/cjs/
  inflating: nodejs/node_modules/@sentry/serverless/build/npm/cjs/awslambda-auto.js
  inflating: nodejs/node_modules/@sentry/serverless/build/npm/cjs/index.js
finishing deferred symbolic links:
  nodejs/node_modules/@sentry/serverless/dist/awslambda-auto.js -> ../build/npm/cjs/awslambda-auto.js

It looks like the right path is @sentry/serverless/build/npm/cjs/awslambda-auto.js. We changed it to this, and our Lambda started running.

[Lms24]

Hi @paulrosania, thanks for reporting!

Yes, it seems like there is a mismatch between the instructions and the folder structure. We should, for now, probably update the readme accordingly.

For the long-run I think we should consider changing this folder structure (build shouldn't be in there). Tagging @lobsterkatie and @antonpirker since the two of you also have context around recent build changes of the Lambda layer.

[tessro]

Thanks! Are we at risk using this path, should we use dist instead in the interim?

[antonpirker]

Hey! Yes I guess changing the path in the instructions is the easiest short term fix for this.

We should probably plan for some love for the serverless integration in general, to fix small bits an pieces.

[aholthagerty]

the information in this readme would be nice to have on the official documentation page.

https://docs.sentry.io/platforms/node/guides/aws-lambda/layer/

This page is notably missing NODE_OPTIONS: -r @sentry/serverless/build/npm/cjs/awslambda-auto as a critical step for setting up sentry via a lambda layer.

edit: only a little annoyed that I have wasted literal hours trying to set up sentry for lambda by following the official docs and this was what I was missing.

[cristiansandru11]

anyone tried to use the layer with a Node Typescript AWS Lambda Function? Already spent two days in order to make it run, the code gets executed but no error is sent to sentry :(