AppHarbor: Discussion

AppHarbor and CORS using pre-flight OPTIONS request

2013-02-04T17:54:17Z

I also asked this question on Stack Overflow, and there's been some help coming through there.

http://stackoverflow.com/questions/14596231/how-do-i-accept-cors-aj...

Removing WebDAV has led to nginx bouncing my requests with a 405 error instead of returning the 200 OK.

Request

OPTIONS $path HTTP/1.1
Host: $servername
Connection: keep-alive
Access-Control-Request-Method: POST
Origin: http://www.local
User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.57 Safari/537.17
Access-Control-Request-Headers: accept, origin, content-type
Accept: /
Referer: http://www.local/wordpress/2013/01/request-url-test/
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-GB,en;q=0.8,en-US;q=0.6
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 405 Method Not Allowed
Server: nginx
Date: Mon, 04 Feb 2013 17:09:19 GMT
Content-Type: application/json; charset=utf-8
Content-Length: 76
Connection: keep-alive
Cache-Control: no-cache
Pragma: no-cache
Expires: -1

AppHarbor and CORS using pre-flight OPTIONS request

2013-02-04T23:51:27Z

WebDAV was to blame for the initial problem of not getting the full CORS headers in the response. The 405 error was a problem somewhere in the configuration of my app.

After some digging into the internals, it appears that the CORSMessageHandler for use with WebAPI (provided by Thinktecture) wasn't correctly identifying preflight requests and those requests were routed through to the WebAPI object itself.

I worked-around the issue by moving to the IIS module instead of the WebAPI one. This may make life more difficult in the future, but at least it works.

AppHarbor and CORS using pre-flight OPTIONS request

2013-02-05T02:00:30Z

Alright that's interesting - so it wasn't related to a configuration issue/snag on AppHarbor? It'd be interesting to know exactly what the issue was when you figure it out.

Best,
Rune

AppHarbor and CORS using pre-flight OPTIONS request

2013-02-05T03:15:03Z

I suspect there's a difference between the request hitting the app on my local development machine and what nginx is sending, but I haven't dug into that. If Thinktecture in IIS mode becomes a major problem I'll look into it again then.