A reply to the above question suggests using
rclone in a similar way to
rsync. It seems like it might work, but it doesn't seem to use the ACL I want.
Previously, I use the aws cli, like this:
aws s3 sync local/ s3://bucket/ --acl public-read --delete
but since my build process regenerates
local/ from scratch each time, that involves copying over a lot of files, which is fine if I happen to have good internet upload speed, but sometimes I don't, hence my desire for rsync-like functionality.
rclone seems like it might fit the bill, except that the files don't have
rclone -v sync local/ remote:bucket
which seemed worked fine, again apart from the acl. Adding
--s3-acl=public-read didn't seem to have any affect.