CORS is not supported by JSON gRPC gateway

[kghost]

Step to reproduce:

start etcd with CORS:

etcd --cors '*'

check CORS:

% curl -X OPTIONS http://localhost:2379/v3beta/kv/range -v -H 'Origin: http://example.com'
*   Trying 127.0.0.1:2379...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 2379 (#0)
> OPTIONS /v3beta/kv/range HTTP/1.1
> Host: localhost:2379
> User-Agent: curl/7.65.1
> Accept: */*
> Origin: http://example.com
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 405 Method Not Allowed
< Content-Type: text/plain; charset=utf-8
< X-Content-Type-Options: nosniff
< Date: Mon, 05 Aug 2019 13:40:42 GMT
< Content-Length: 19
< 
Method Not Allowed
* Connection #0 to host localhost left intact

And CORS only set up on 404 request:

% curl -X OPTIONS http://localhost:2379/404 -v -H 'Origin: http://example.com'
*   Trying 127.0.0.1:2379...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 2379 (#0)
> OPTIONS /404 HTTP/1.1
> Host: localhost:2379
> User-Agent: curl/7.65.1
> Accept: */*
> Origin: http://example.com
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Access-Control-Allow-Headers: accept, content-type, authorization
< Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT, DELETE
< Access-Control-Allow-Origin: *
< Date: Mon, 05 Aug 2019 13:41:05 GMT
< Content-Length: 0
< 
* Connection #0 to host localhost left intact

[hexfusion]

Thanks for the report we can look at adding this support.

[kghost]

I found it is already implemented in master branch, is it going to backport to 3.3 branch ?

[hexfusion]

I found it is already implemented in master branch, is it going to backport to 3.3 branch ?

You are correct, but as this is a feature in 3.4 [1],[2] that requires server flag param we probably can not backport. Reason being some 3.3.x server would support the flag while others would not. In the later case, it could cause etcd to not start if the flag were passed.

[1] #9490
[2] https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.4.md#security-authentication

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed after 21 days if no further activity occurs. Thank you for your contributions.