Support Sentry Lambda Extension with container image-based Lambda functions

[Hoffs]

Problem Statement

The Sentry Lambda Extension (#17525) tunnels events through a local proxy, solving event delivery issues during Lambda freezes. However, it's only usable via the Lambda Layer ARN, which cannot be attached to container image-based Lambda functions.

We run a SvelteKit app on AWS Lambda using Lambda Web Adapter with a container image. The wrapHandler + flush() pattern doesn't apply since Lambda Web Adapter bypasses the handler. The extension would solve our event delivery reliability.

The only workarounds are vendoring the extension files from the layer zip into the Docker image or extracting them at build time via AWS CLI — both are fragile.

Solution Brainstorm

• Publish the extension as a standalone Docker image (like public.ecr.aws/awsguru/aws-lambda-adapter) for use with COPY --from= in Dockerfiles
• Publish as an npm package installable and copyable to /opt/extensions/
• Document the recommended approach for container image Lambdas, including how to use tunnel: 'http://localhost:9000/envelope' with @sentry/sveltekit or @sentry/node

Additional Context

• @sentry/aws-serverless init.ts gates the extension behind sdkSource === 'aws-lambda-layer', which doesn't pass when using the SDK via npm
• Container image Lambdas are common for web frameworks using Lambda Web Adapter (SvelteKit, Next.js, Remix)

[linear-code]

JS-2049

[andreiborza]

Hi @Hoffs, thanks for writing in.

I'm not sure yet if we want to maintain a specific docker image or a new npm package for this, but we could probably make the extension accessible in the npm package and provide documentation on how to copy it over. We would also relax the gate for the extension so that it's usable via npm too.

The caveat of course is that if you use Lambda Web Adapter with a non @sentry/aws-serverless sentry SDK, you'd have to install this one along just to copy over the extension and then manually set the tunnel in the option. Not ideal, but I think acceptable as a first step, but I'd love to hear your thoughts on that.

[Hoffs]

The caveat of course is that if you use Lambda Web Adapter with a non @sentry/aws-serverless sentry SDK, you'd have to install this one along just to copy over the extension and then manually set the tunnel in the option. Not ideal, but I think acceptable as a first step, but I'd love to hear your thoughts on that.

Yeah, I think that sounds totally fair! As long as it gets registered as extension via lambda API and it functions as expected, I think that would be pretty good.