Fixes reading of CORS pre-flight headers and methods

[abeyad]

CORS headers and methods config parameters must be read as arrays. This
commit fixes the issue. It affects http.cors.allow-methods and
http.cors.allow-headers.

Backports #17523

[skundrik]

Fixes #17483 Problems with http.cors.allow-methods

[abeyad]

Closed by Commit 1ecc627

[uschindler]

Thanks for fixing. I have seen the same on my server. But I was able to fix with reverse proxy, so I did not care too much.

In my case the issue came from the fact that I only allowed GET and POST in my configuration.

I will try 2.3.2 and report if it's fixed.

[abeyad]

@uschindler Thank you!

[uschindler]

I can confirm: 2.3.2 works again without reverse proxy hack

[abeyad]

@uschindler Great, thanks for confirming

[ieatbytes]

can you please guide me what to write in elasticsearch.yml? i used to work like
network.host: 0.0.0.0 and it was working like charm

[abeyad]

@ieatbytes I am not sure what you mean? None of the properties in elasticsearch.yml related to CORS handling have changed.