Absolutely, this is very important, as debugging it is not trivial. Particularly, which headers must be allowed. On Google Cloud Storage, these are the headers that I need to allow for direct upload to work properly (the Content-Md5 was a gotcha):

Access-Control-Allow-Headers: Content-Type, Content-Length, Content-Md5

Hi @georgeclaghorn and @lucaong ,

I did not configurate the header to direct upload, but attached a policy to EC2 with Action: s3:*, maybe it solved.

Should I let my bucket public for List objects? Only with that I could make upload and show works.

This issue has been automatically marked as stale because it has not been commented on for at least three months.
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fixed via #34028

This just bit me in production, I would really appreciate documentation on this!