Here's how to create a Amazon S3 special remote that can be read by anyone who gets a clone of your git-annex repository, without them needing Amazon AWS credentials.
Note: Bear in mind that Amazon will charge the owner of the bucket for public downloads from that bucket.
create public remote
First, export your Amazon AWS credentials:
# export AWS_ACCESS_KEY_ID="08TJMT99S3511WOZEP91" # export AWS_SECRET_ACCESS_KEY="s3kr1t"
Now, create the remote:
# git annex initremote pubs3 type=S3 encryption=none public=yes initremote pubs3 (checking bucket) (creating bucket in US) ok
The public=yes is the crtical part; this lets the public read the contents of the bucket. (This feature needs git-annex 5.20150617 or newer.)
In the above example, no encryption was used, but it will also work if you enable encryption=shared. Then files will be encrypted on S3, and anyone with a clone of the git repository will be able to download and decrypt them.
It's also ok to enable chunking when setting up the remote.
Now, copy some files to the remote, in the usual way, and push your git repository to someplace where someone else can access it.
use public remote
Once the S3 remote is set up, anyone who can clone the git repositry can get files from the remote, without needing any Amazon AWS credentials.
Start by checking out the git repository.
In the checkout, enable the S3 remote:
# git annex enableremote pubs3 enableremote pubs3 ok
Now, git-annex can be used as usual to download files from that remote.
You can also share urls to files stored in a public S3 remote to people
who are not using git-annex. To find the url, use
git annex whereis.
See S3 for details about configuring S3 remotes.
See publishing your files to the public for other ways to use a public S3 bucket.