Cloud Encrypted Sync

Cloud Encrypted Sync (CES) is a command line tool distributed as a Ruby gem for syncing a local folder to cloud storage via external adapters, with localy managed encryption (you control the keys).

Even though you could simply use CES to backup a local folder to the cloud, it's original intended purpose is to sync a folder across multiple computers, so it should work for that, too.

gem install cloud_encrypted_sync

In addition to this gem you'll also need to install an adapter gem for the particular cloud you want to backup to. At the time of this writing, the author has provided two adapters, one for Amazon S3 (cloud_encrypted_sync_s3_adapter) and one for local filesystems (cloud_encrypted_sync_filesystem_adapter) which has been tested to work with Ubuntu One and Dropbox folders, and should work well with any other cloud storage service that uses similar "magic" folders on the local file system. In addition, anyone can create an adapter to work with other clouds. Search rubygems.org for "cloud encrypted sync" to find out if someone has already created an adapter for your preferred cloud.

CES runs as a command line tool and takes options as CLI arguments and/or from a config file. Arguments passed at the command line take precedence over those in the config file.

ces --adapter s3 \
  --s3-bucket my-backup-bucket \
  --s3-access-key-id ACCESS_KEY_ID \
  --s3-access-id SECRET_ACCESS_KEY \
  --encryption-key MYENCRYPTIONKEY \
  /path/to/source/folder

Configuration options may be passed to CES via the command line, or via a config yaml file.

The default location for the config file is ~/.cloud_encrypted_sync/config.rc.yml

CES requires the following configuration settings. Any of these may alternatively be placed in the config.rc.yml except for --data-dir (which tells CES which folder contains the config file to use).

• --adapter ADAPTERNAME The name of the adapter to use. See instructions for your preferred adapter for instructions of what to place here.
• --encryption-key XXX The encryption key (shocking, I know).

In addition to these settings, your chosen adapter will probably also have additional adapter specific settings as well, such as credentials to log into your cloud storage account. Adapter specific settings may work the same the the above standard settings in that they may be included on the command or in the config.rc.yml file (unless the adapter author breaks convention and tries to do something weird).

To create your own adapter to a cloud storage service, you'll need to do the following.

• Create a Ruby Gem named cloud_encrypted_sync_*_adapter where * is the name of your adapter. It is recommended that you name your adapter after the cloud service that it interfaces to. (eg. cloud_encrypted_sync_s3_adapter ). CES will not be able to find and load your adapter unless it precisely matches this naming convention.
• Your gem needs to provide a class within the CloudEncryptedSync::Adapters namespace that inherites from Template. The name of this class will determine the value that users pass with --adaper on the command line to select your adapter. For instance, if you name your class MySuperDooperAdapter, then users will need to pass --adapter my_super_dooper_adapter at the command line to select your adapter.
• See the Baseline class in cloud_encrypted_sync_baseline_adapter for a list of methods that your adapter class needs to respond to, what arguments they need to accept, and what values they're expected to return.

Note: cloud_encrypted_sync_baseline_adapter is a forkable repository that should make the above steps easier. Simply fork it, rename it, update it as necessary, and push it to rubygems.org.

It is likely that, before publishing your new adapter to rubygems.org, you'll want to build and install your gem locally to test it with CES. When you do this you'll also want to have the CES gem itself built and installed locally, rather than installed from rubygems.org. It has been found that when CES has been installed from rubygems.org, it is unable to find and load locally built adapters, and visa-versa. The CES author is very interested in any patches that provide an elegant solution to this annoyance.