feat(frontend) Allow overriding akka-max-header-value-length

[karoliskascenas]

Allows overriding max-header-value-length via environment variables. This should enable users to solve the following issue:
akka.actor.ActorSystemImpl - Illegal request, responding with status '431 Request Header Fields Too Large': HTTP header value exceeds the configured limit of 8192 characters

[github-actions]

Unit Test Results (build & test)

334 tests  ±0   334 ✔️ ±0   2m 46s ⏱️ -32s
  78 suites ±0       0 💤 ±0 
  78 files   ±0       0 ❌ ±0 

Results for commit 0a3498e. ± Comparison against base commit 928db39.

♻️ This comment has been updated with latest results.

[jjoyce0510]

Nice! Thank you!

cc @RyanHolstien to take a quick look as well.

[RyanHolstien]

This setting is already exposed as configurable through the play configuration. Instead of modifying the custom configurations, please just add a variable setting play.server.max-content-length

[RyanHolstien]

See: https://www.playframework.com/documentation/2.8.x/SettingsAkkaHttp

And
playframework/playframework#7990

[jjoyce0510]

Let's try what @RyanHolstien has suggested - if its possible, we can make that change and should be good to merge! If there's any issue, let us know.

[karoliskascenas]

@RyanHolstien was looking at docs for 2.7.6 and it seems like the setting should be play.server.akka.max-header-value-length. Sorry I have close to no experience with neither play or akka. Let me know if this is fine.

[RyanHolstien]

@karoliskascenas Yes this looks right! Sorry for putting the wrong variable name in my previous comment.

[jjoyce0510]

Will merge once this passes CI.

[TobiasGoerke]

Setting the docker container's env variable DATAHUB_AKKA_MAX_HEADER_VALUE_LENGTH to e.g. 10k seems to have no effect and still results in HTTP header value exceeds the configured limit of 8192 characters.
Am I missing something? Thanks!

Edit: found the answer. Setting max-header-value-length works while max-header-size doesn't. Former is deprecated though and advises to use latter one.