Which has a dashboard and can of course be self-hosted.
Minio - https://min.io/ it is S3 compliant, has an UI and can also be self-hosted.
Saw the post, immediately thought of this, I’m using it and it works 👌
I use Minio https://github.com/minio/minio, though there are others. As someone who never worked with s3 before but wanted to try it and use it with some apps that supported s3 as a storage target, it’s been working fine for me though I’m certainly not using it to its potential. Has web access and all.
Others might be:
Super Simple Storage? There are options like MinIO and SeaweedFS that I know of but I have never used them personally.
IDK about a dashboard but SeaweedFS with the S3 filer is dead simple to self host and will even do a bit of identity policy.
Ceph
