IssueTracker

Problem you have encountered:

When using custom domains for GAE (flex, but not sure if that's relevant), Google Frontend does not cache static assets.

What you expected to happen:

I expected Google Frontend to cache static assets.

Steps to reproduce:

Compare results of:

curl --head https://next-app-dot-fireside-prod-285316.uc.r.appspot.com/_next/static/chunks/9552.cc35e946c75f8f72.js

HTTP/2 200 
content-length: 1494
vary: Accept-Encoding,Accept-Encoding
strict-transport-security: max-age=15552000; includeSubDomains; preload
accept-ranges: bytes
via: 1.1 google
date: Wed, 09 Nov 2022 14:26:37 GMT
cache-control: public, max-age=31536000, immutable
last-modified: Tue, 18 Oct 2022 11:21:00 GMT
etag: W/"5d6-183ead34d60"
content-type: application/javascript; charset=UTF-8
age: 148
alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000,h3-Q050=":443"; ma=2592000,h3-Q046=":443"; ma=2592000,h3-Q043=":443"; ma=2592000,quic=":443"; ma=2592000; v="46,43"

curl --head https://firesidechat.com/_next/static/chunks/9552.cc35e946c75f8f72.js

HTTP/2 200 
date: Wed, 09 Nov 2022 14:29:43 GMT
content-type: application/javascript; charset=UTF-8
content-length: 1494
vary: Accept-Encoding
vary: Accept-Encoding
strict-transport-security: max-age=15552000; includeSubDomains; preload
cache-control: public, max-age=31536000, immutable
accept-ranges: bytes
last-modified: Tue, 18 Oct 2022 11:21:00 GMT
etag: W/"5d6-183ead34d60"
via: 1.1 google

The first request has the age header, while the second one doesn't.

Other information (workarounds you have tried, documentation consulted, etc):

Sounds very similar to https://issuetracker.google.com/issues/65051112, which is an issue from 2015. I don't know what the policy on issue age is, if this counts as a duplicate please close it and I'll post the details in the old issue.