上传对象

var params = {
    Bucket: "<your-bucket-name>",
    Key: "<your-key-name>",
    Body: Buffer.from('...') || 'STRING_VALUE' || streamObject,
    ACL: "private", // 初始化acl权限，默认为private，"private"|"public-read"|"public-read-write"
    ContentType: "text/plain", // 设置contentType, 默认是application/octet-stream
};
s3.putObject(params, function(err, data) {
    if (err) 
        console.log(err, err.stack);
    else     
        console.log(data);
});