cloudlib is a system for maintaining a database of electronic papers
and books using Amazon's web services (for background, see
http://aws.amazon.com/).  Think of it as an indefinitely extensible
personal library, accessible from anywhere in the world.

The papers and books themselves are stored in a S3 bucket. The
metadata are stored in a SimpleDB database, so they can be searched easily.
The cloudlib ruby library integrates these two components and insulates
the user from the S3- and SimpleDB-specific details.

Note that S3 and SimpleDB are pay services. You will pay Amazon
proportionally to your usage.  As of this writing (December 2008),
SimpleDB is free for the kind of usage this library normally requires.
For S3, the fee in North America is $0.15/GB/month for storage.
(See http://aws.amazon.com/s3/#pricing for up-to-date figures, including
fees for data transfer.) At these rates, it will cost less than a tenth
of a cent to store an average journal article for a year, and less than
a penny to store a good-sized book.

In addition to a ruby library, two programs are provided:

- cloudlib offers a command-line interface for interacting with a library. 

- cloudlib-web starts a web-server which can either be used locally
  (so that the library can be controlled through a browser) or made available
  on the open internet.  HTTP authentication is used to password-protect
  the web application.

Both programs assume that the following environment variables have been set.
(If they are not, they will prompt for these values.)

- CLOUDLIB_LIBRARY_NAME - a name, of your choosing, that will identify the
  library.  It will be used both for the S3 bucket and the SimpleDB domain.
  S3 bucket names must be unique, so pick a name like
  'your-name-library', not something generic like 'my-library'.

- AWS_ACCESS_KEY_ID - the access key id you are provided when you sign up
  for Amazon web services.

- AWS_SECRET_ACCESS_KEY - the secret key you are provided  when you sign
  up for Amazon web services.

cloudlib-web also assumes that the following environment variables have
been set:

- CLOUDLIB_WEB_USERNAME - a username of your choice, to be used to gain
  access to the web interface.

- CLOUDLIB_WEB_PASSWORD - a password of your choice, to be used to gain
  access to the web interface.

These environment variables can be set as follows:

    export AWS_ACCESS_KEY_ID=xxxx-my-key-id-xxx
    export AWS_SECRET_ACCESS_KEY=xxx-my-key-xxx
    export CLOUDLIB_LIBRARY_NAME=xxx-my-library-name-xxx
    export CLOUDLIB_WEB_USERNAME=xxx-username-xxx
    export CLOUDLIB_WEB_PASSWORD=xxx-password-xxx

You may want to put these commands in a file, cloudlib-setup,
so that you can set all the variables at once:

    source cloudlib-setup

After setting the environment variables, but before doing anything else,
you will need to create your library:

    cloudlib new-library

If that succeeds, you can use either cloudlib or cloudlib-web to access
the library.  By default, cloudlib-web will start a webserver on port 4567.
(This can be changed using the -p PORT option.)  To use the web interface
after you've started the server, just point your browser at <http://localhost:4567>.

For instructions on the use of cloudlib, try

    cloudlib --help

cloudlib by itself will start an interactive session.  To add a new file,
use

    cloudlib add /path/to/file

The commands 'dump' and 'restore' are also provided to allow creation of
a local backup of the database.

To install cloudlib:

    gem sources -a http://gems.github.com        # you only have to do this once
    sudo gem install jgm-cloudlib

Known bugs:

* The web interface doesn't work in Chrome (and probably other browsers).
  It does work in Firefox.  The culprit: onClick attributes on option
  tags, which aren't technically allowed.