Permissions using an IAM role

[m0ppers]

First of all thank you for providing (and maintaing!) this docker image.

We have a minor usability problem: We are using iam roles to handle permissions on AWS. Unfortunately the docker container has a hard check that there is either an authfile or key pair.

My workaround is currently to provide an empty authfile so that the docker entrypoint is happy and then I pass "iam_role=auto" via S3FS_ARGS. This is working fine but I thought I would report anyway as this usecase doesn't seem to be on the radar.

super low priority.

[efrecon]

Thanks for mentioning. Maybe would you like to add a little "how to?" section to the main README.md as a starter, that would help people having the same usecase as yours? I'd be happy to take in a PR.