Akka reports facebook in-app browser as an illegal user agent

[michaelwmcnamara]

Sample log:

2017-07-22 17:22:31,719 [application-akka.actor.default-dispatcher-19059] WARN akka.actor.ActorSystemImpl - Illegal header: Illegal 'user-agent' header: Invalid input '[', expected 'EOI', product-or-comment, WSP, comment or CRLF (line 1, column 111): Mozilla/5.0 (iPhone; CPU iPhone OS 10_3_2 like Mac OS X) AppleWebKit/603.2.4 (KHTML, like Gecko) Mobile/14F89 [FBAN/FBIOS;FBAV/133.0.0.51.89;FBBV/65438308;FBDV/iPhone6,2;FBMD/iPhone;FBSN/iOS;FBSV/10.3.2;FBSS/2;FBCR/EE;FBID/phone;FBLC/en_GB;FBOP/5;FBRV/0]

useful reference: https://stackoverflow.com/questions/11414006/is-this-a-facebook-for-ios-webview-user-agent

[davidfurey]

The facebook user-agent does not comply with the RFC. This log is just a warning, the request is still processed correctly. I'm not sure that we can do anything until akka/akka-http#687 is resolved.

[michaelwmcnamara]

Reopening this as it looks like Akka introduced the ability to disable warnings for certain headers on 7th May 2018. Presumably this will mean updating the version we use and also creating a list of specific headers to ignore. Will look into doing this and update as I go.

[michaelwmcnamara]

This is now resolved.
A later version of Play incorporated some Akka fixes that resolved this.
We have updated to the latest version of Play 2.6.16 and issue no longer occurs.