Passing correct Host header to _next/data/*

[Qubica]

Hello,

I'm setting up a Multilang Serverless NextJS project.
Based on the Host Header I like to retrieve the correct language via getServerSideProps.
domain.nl -> dutch, domain.eu -> english, domain.de -> german, ... etc

This is working for the dev server, on page load and on client side routing.
On AWS it's working for page load but failing for client side routing (_next/data/*)
When navigating on the client it's receiving the s3 domain as Host instead of the actual origin.
In Cloudfront I've added Host to the whitelist headers.

Who can help me solve this?

[dphang]

Host header is explicitly set to S3 host for S3 origin requests. This applies to all S3 requests including SSG data requests: https://github.com/serverless-nextjs/serverless-next.js/blob/master/packages/libs/lambda-at-edge/src/default-handler.ts#L308

Originally this was added in PR: #412.

But I believe you are talking about SSR data requests since you mention getServerSideProps, so I don't think above applies. Two things:

1. Are you also forwarding Host header for _next/data cache behavior in addition to default cache behavior? Because otherwise the host header is set to s3 origin host (AWS behavior).

2. You may also need to use latest alpha (1.17-alpha.16) as well as I made a fix for a bug where SSR data requests were trying to go to S3 (which would have overwritten the host header as per above) instead of directly rendered in Lambda origin request handler: 2fa8910. It may fix the issue for you.

[Qubica]

Thank you for the quick reply!
Updating to the latest alpha release is doing the trick.
Great!