This special remote type stores file contents in a bucket in Amazon S3
or a similar service.

See [[tips/using_Amazon_S3]] and
[[tips/Internet_Archive_via_S3]] for usage examples.

## configuration

The standard environment variables `AWS_ACCESS_KEY_ID` and 
`AWS_SECRET_ACCESS_KEY` are used to supply login credentials
for Amazon. You need to set these only when running
`git annex initremote`, as they will be cached in a file only you
can read inside the local git repository.

A number of parameters can be passed to `git annex initremote` to configure
the S3 remote.

* `encryption` - Required. Either "none" to disable encryption (not recommended),
  or a value that can be looked up (using gpg -k) to find a gpg encryption
  key that will be given access to the remote, or "shared" which allows
  every clone of the repository to access the encrypted data (use with caution).

  Note that additional gpg keys can be given access to a remote by
  running enableremote with the new key id. See [[encryption]].

* `embedcreds` - Optional. Set to "yes" embed the login credentials inside
  the git repository, which allows other clones to also access them. This is
  the default when gpg encryption is enabled; the credentials are stored
  encrypted and only those with the repository's keys can access them.

  It is not the default when using shared encryption, or no encryption.
  Think carefully about who can access your repository before using
  embedcreds without gpg encryption.

* `datacenter` - Defaults to "US". Other values include "EU",
  "us-west-1", and "ap-southeast-1".

* `storageclass` - Default is "STANDARD". If you have configured git-annex
  to preserve multiple [[copies]], consider setting this to "REDUCED_REDUNDANCY"
  to save money.

* `host` and `port` - Specify in order to use a different, S3 compatable
  service.

* `bucket` - S3 requires that buckets have a globally unique name, 
  so by default, a bucket name is chosen based on the remote name
  and UUID. This can be specified to pick a bucket name.

* `fileprefix` - By default, git-annex places files in a tree rooted at the
  top of the S3 bucket. When this is set, it's prefixed to the filenames
  used. For example, you could set it to "foo/" in one special remote,
  and to "bar/" in another special remote, and both special remotes could
  then use the same bucket.

* `x-amz-*` are passed through as http headers when storing keys
  in S3.
