Rails ActionText/ActiveStorage error code 0

Recently I built out a new model which utilizes ActionText and by extension ActiveStorage so that I can embed attachments and images.

However, when I tested it locally it didn't work. It left a cryptic error:

failed to upload <image name> error code 0

I dug around, and found this post which indicated that perhaps my AWS S3 CORS configuration was to blame.

Sure enough, I was able to fix it by navigating to my S3 CORS settings located under the "Permissions" tab (https://us-east-1.console.aws.amazon.com/s3/buckets/<bucket name>?region=<region>&tab=permissions) and added this CORS configuration:

[
    {
        "AllowedHeaders": [
            "Content-Type",
            "Content-MD5",
            "Content-Disposition"
        ],
        "AllowedMethods": [
            "PUT"
        ],
        "AllowedOrigins": [
            "http://localhost:3000",
            "https://adamtaylor.me"
        ],
        "ExposeHeaders": [],
        "MaxAgeSeconds": 3600
    }
]

After that, all my attachments worked correctly!