<?xml version="1.0" encoding="UTF-8"?>
<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
<CORSRule>
    <AllowedOrigin>*</AllowedOrigin>
    <AllowedMethod>GET</AllowedMethod>
    <AllowedHeader>*</AllowedHeader>
</CORSRule>
</CORSConfiguration>

fabric.Image.fromURL(URL, function(image) {
    [...]
.bind(this),{
    crossOrigin: 'anonymous'
});

document.querySelector("#canvas").toDataURL();

curl -H "Access-Control-Request-Method: GET" -H "Origin: http://localhost:8000" --head https://XXXX.png