Drop 'support-cors' usersync YAML config

[bretg]

Since before even my time in PBS, the YAML files have supported a 'support-cors' field in usersync. Of 230+ bid adapters, only 2 set this to true.

I don't see any code in PBS that looks at this field.

My suspicion is that it's an information flag indicating that the bidder's sync endpoint sets some specific CORS header like Access-Control-Allow-Credentials and/or Access-Control-Allow-Origin. However, That's not documented anywhere and I'm not aware of the use case that drive this ancient config setting.

So I'm proposing that we either:

• drop support-cors from the usersync YAML entirely
• OR document what use case it supports and when bidders should declare support-cors:true

[bretg]

The cookie_sync endpoint does send this value to the client, but the pbsBidAdapter doesn't use it.

[bsardo]

I only see three instances of this in PBS-Go YAML files:
stroeerCore.yaml
imds.yaml
orbidder.yaml

[philipwatson]

Hi @bsardo & @bretg

The stroeerCore.yaml you referenced is some sort of test file that we didn't create or contribute to: config/test/bidder-info-valid/stroeerCore.yaml

The actual yaml file: static/bidder-info/stroeerCore.yaml (no support-cors there).

[arneschulz1984]

Dear Prebid-Server Developers, @bretg,

we (Orbidder Developers) had set "supportCORS" to true, because the Sync Endpoint support CORS.
But there is no other spezial behavior than handling an "OPTIONS" request at our implementation.
So from our side it is fine to remove the flag, if there is no need for it.

Greetings
Team Orbidder