Cors configuration

[lfoppiano]

This should resolve #226

[coveralls]

Coverage increased (+0.02%) to 37.331% when pulling 8ad022d on cors-configuration into f0457c8 on master.

[Aazhar]

This is ok for me

[kermitt2]

Just tested it, if I didn't make an error, I don't see the CORS info in the response header:

Current master server response headers:

HTTP/1.1 200 OK
Date: Sat, 28 Dec 2019 15:10:21 GMT
Content-Type: application/xml; charset=UTF-8
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, DELETE, PUT
Transfer-Encoding: chunked

PR server response headers (with CORS default config in grobid-service/config/config.yaml):

HTTP/1.1 200 OK
Date: Sat, 28 Dec 2019 15:07:29 GMT
Content-Type: application/xml; charset=UTF-8
Transfer-Encoding: chunked

[Aazhar]

Just tested it, if I didn't make an error, I don't see the CORS info in the response header:

Current master server response headers:

HTTP/1.1 200 OK
Date: Sat, 28 Dec 2019 15:10:21 GMT
Content-Type: application/xml; charset=UTF-8
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, DELETE, PUT
Transfer-Encoding: chunked

PR server response headers (with CORS default config in grobid-service/config/config.yaml):

HTTP/1.1 200 OK
Date: Sat, 28 Dec 2019 15:07:29 GMT
Content-Type: application/xml; charset=UTF-8
Transfer-Encoding: chunked

I tried it with ajax/jquery and it is ok ! , I ll do further tests, something weird..

[lfoppiano]

I need to have a look at it again ...

[lfoppiano]

Basically this implementation does not return headers if the Origin doesn't match the allowed origin or it's absent... it seems the proper way to do so, but it's not as I remember this thing...

[kermitt2]

ah my bad, I didn't put Origin: http://localhost in the requesting header indeed! I though corsAllowedOrigins: "*" would also match an absent Origin field.

Adding for instance Origin: http://localhost with the default server config works as expected - in the server response header, we have Access-Control-Allow-Origin: http://localhost Access-Control-Allow-Credentials: true.

[lfoppiano]

I just added some minor corrections which were stuck in my local branch with 66de8d5