Hi there!<\/p>\n
Just wanted to make a quick post about an error message (Response for preflight is invalid – redirect)<\/em>\u00a0that can probably confuse someone while working with Amazon S3 uploads directly from the browser.<\/p>\n I’d been testing uploads to Amazon S3 using Ember Plupload<\/a>\u00a0(a wrapper around Plupload<\/a>) to\u00a0a development bucket directly from the browser.\u00a0I activated CORS by using this example<\/a> and the S3 example<\/a> in Ember Plupload page as it was required for direct uploads.<\/p>\n After I got everything working, I decided to create a “production” bucket and deploy my application pointing to that new bucket. Immediately I started getting this strange error in Chrome’s network tab while making the preflight request (the OPTIONS request).<\/p>\n Response for preflight is invalid (redirect) – 307<\/p><\/blockquote>\n Essentially the response was a 307 redirect, instead of the 200 OK that I was expecting, and that was working on the development bucket.<\/p>\n Since uploading to the development bucket was working, it could only be some configuration or state that was wrong.<\/p>\n I checked and double checked the configurations and they were the same. I started googling without finding anything that helped.<\/p>\n I then looked really good at the response and noticed that the redirect was to a slightly different link than what I was expecting, it was redirecting me “https:\/\/mybucket.s3-eu-west-1<\/strong>.amazonaws.com” instead of the original url which was “https:\/\/mybucket.s3<\/strong>.amazonaws.com”.<\/p>\n I\u00a0tried changing the upload url to this “redirect” and it started working, I checked the responses for the development bucket, and there was no mention of the “s3-west-1” anywhere.<\/p>\n After that I found this comment on github<\/a>:<\/p>\n The reason his happens (and also the reason why it self-resolves), is that when you set up an S3 bucket, there’s a certain time during which the global bucket URL is not available, so AWS redirects to the region-specific URL.<\/p>\n The redirect response that Amazon sends back when you request the global URL doesn’t have CORS headers, so requests will fail until the DNS has propagated.<\/p><\/blockquote>\n Which has a reference to S3’s documentation:<\/p>\n From the documentation:<\/p>\n Temporary redirects automatically redirect users who do not have DNS information for the requested bucket. This occurs because DNS changes take time to propagate through the Internet. For example, if a user creates a bucket with a location constraint and immediately stores an object in the bucket, information about the bucket might not yet have been distributed throughout the Internet. Because the bucket is a subdomain of s3.amazonaws.com, Amazon S3 redirects it to the correct Amazon S3 location.<\/p><\/blockquote>\n<\/blockquote>\n So, I basically only had to wait until Amazon propagated DNS information (took about 2 hours or so, I think). But since it didn’t happen with the development bucket (which I created before I started developing…. so, it makes sense) I got lost there.<\/p>\n Well, I hope that this might spare you some headaches…. just wait a bit \ud83d\ude42<\/p>\n Happy coding!<\/p>\n","protected":false},"excerpt":{"rendered":" Response for preflight is invalid – redirect 307 Hi there! Just wanted to make a quick post about an error message (Response for preflight is invalid – redirect)\u00a0that can probably confuse someone while working with Amazon S3 uploads directly from … Continue reading