tahoe-lafs/README

Welcome to the AllMyData "tahoe" project. This project implements a
secure, distributed, fault-tolerant storage grid.

The basic idea is that the data in this storage grid is spread over all
participating nodes, using an algorithm that can recover the data even if a
majority of the nodes are no longer available.

The interface to the storage grid allows you to store and fetch files, either
by self-authenticating cryptographic identifier or by filename and path.


GETTING THE SOURCE CODE:

 The code is available via darcs by running the following command:

 darcs get http://allmydata.org/source/tahoe/trunk

 See http://allmydata.org for all kinds of information, news, and community
 contributions.


LICENCE:

 Tahoe is offered under the GNU General Public License (v2 or later), with
 the added permission that, if you become obligated to release a derived work
 under this licence (as per section 2.b), you may delay the fulfillment of
 this obligation for up to 12 months.  See the COPYING file for details.


DEPENDENCIES:

 Note: All of the following dependencies can probably be installed through
 your standard package management tool if you are running on a modern Unix
 operating system.  If you are running any modern Linux or *BSD distribution
 then you can get them through your standard package manager.  If you are
 running Mac OS X then be warned that the "fink" package management tool does
 not have most of these packages, but the "darwinports" package management
 tool appears to have them.  If you are running on Windows then I'm afraid
 you'll have to install them by hand (although the "cygwin" package
 management tool does have some of them).  If you are running on Solaris, 
 I would like to hear from you -- I have no idea how it is done on Solaris 
 nowadays.

 * a C compiler (language)

 * GNU make (build tool)

 * Python 2.4 or newer (tested against 2.4, and 2.5.1, but v2.5 or higher is
   required on Windows-native), including development headers (language)

   http://python.org/

 * Python Twisted (tested against both 2.4 and 2.5) (network and operating
   system integration library)

   http://twistedmatrix.com/

   You need the following subpackages, which are included in the default
   Twisted distribution:

   * core (the standard Twisted package)
   * web, trial, conch

   Twisted requires zope.interface, a copy of which is included in the
   Twisted distribution.

 * Python Nevow (probably 0.9.0 or later) (web presentation language)

   http://divmod.org/trac/wiki/DivmodNevow

 * Python setuptools (build and distribution tool)

   http://peak.telecommunity.com/DevCenter/EasyInstall#installation-instructions

   Note: the build process will automatically download and install setuptools
   if it is not present.  However, if an old, incompatible version of
   setuptools (< v0.6c3) is present then the build will fail.  Therefore, if
   the build fails due to setuptools not being compatible, you can either
   upgrade or uninstall your version of setuptools and try again.

 * Python PyOpenSSL (0.6 or later) (secure transport layer)

   http://pyopenssl.sourceforge.net

   To install PyOpenSSL on Windows-native, download this:
   http://allmydata.org/source/pyOpenSSL-0.6.win32-py2.5.exe

 * to build the debian packages you will need all the usual debian-packaging
   tools, which means the 'build-essential' metapackage and all of the
   packages listed as "Build-Depends" in DIST/debian/control for your
   distribution. You will also want the 'fakeroot' package to allow the
   top-level 'make deb-DIST' targets work.

 * on Windows, the pywin32 package

   http://sourceforge.net/projects/pywin32/

 On debian systems, these dependencies can be handled by installing the
 following packages: build-essential, python-dev, python-twisted,
 python-nevow, python-setuptools, python-pyopenssl, fakeroot.


BUILDING:

 Just type 'make'. This works on Windows too, provided that you have the
 dependencies mentioned above (either a normal cygwin build or a mingw-style
 native build is supported by the makefile -- the cygwin build is the
 default).

 If the desired version of 'python' is not already on your PATH, then type
 'make PYTHON=/path/to/your/preferred/python'.

 'make test' runs the unit test suite.


INSTALLING:

 The Debian Way:

  If you're running on a debian system, use 'make deb-dapper', 'make
  deb-sid', 'make deb-edgy', or 'make deb-feisty' to construct two debian
  packages named 'allmydata-tahoe' and 'python-foolscap' which you can then
  install.

 The Python Way:

  You'll need to run four separate install steps, one for each of the four
  subpackages (allmydata, allmydata.Crypto, foolscap, and zfec).  If you use
  GNU stow, add the options "--prefix=." and
  "--root=/usr/local/stow/${PACKAGE}" to the "setup.py install" command.

   for PACKAGE in zfec Crypto foolscap ; do
     cd src/${PACKAGE} && python setup.py install && cd ../..
   done

   # the tahoe subpackage's setup.py script is in the root directory
   PACKAGE=tahoe
   python setup.py install

 The Running-In-Place Way:

  To run from a source tree (without installing first), type 'make', which
  will put all the necessary libraries into a local directory named
  "./instdir/lib", which you can then add to your PYTHONPATH .  (It will put
  executables into "./instdir/bin".)


 To Test That It Is Properly Installed:

  To test that all the modules got installed properly, start a python
  interpreter and import modules as follows:

   % python
   Python 2.4.4 (#2, Jan 13 2007, 17:50:26)
   [GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)] on linux2
   Type "help", "copyright", "credits" or "license" for more information.
   >>> import zfec
   >>> import allmydata.Crypto
   >>> import foolscap
   >>> import allmydata.interfaces


RUNNING:

 If you installed one of the debian packages constructed by "make deb-*" then
 it creates an 'allmydata-tahoe' executable, usually in /usr/bin . If you
 didn't install a package you can find allmydata-tahoe in ./instdir/bin/
 . This tool is used to create, start, and stop nodes. Each node lives in a
 separate base directory, inside of which you can add files to configure and
 control the node. Nodes also read and write files within that directory.

 A grid consists of a single central 'introducer and vdrive' node and a large
 number of 'client' nodes. If you are joining an existing grid, the
 introducer-and-vdrive node will already be running, and you'll just need to
 create a client node. If you're creating a brand new grid, you'll need to
 create both an introducer-and-vdrive and a client (and then invite other
 people to create their own client nodes and join your grid).

 The introducer (-and-vdrive) node is constructed by running 'allmydata-tahoe
 create-introducer --basedir $HERE'. Once constructed, you can start the
 introducer by running 'allmydata-tahoe start --basedir $HERE' (or, if you
 are already in the introducer's base directory, just type 'allmydata-tahoe
 start'). Inside that base directory, there will be a pair of files
 'introducer.furl' and 'vdrive.furl'. Make a copy of these, as they'll be
 needed on the client nodes.

 To construct a client node, pick a new working directory for it, then run
 'allmydata-tahoe create-client --basedir $HERE'. Copy the two .furl files
 from the introducer into this new directory, then run 'allmydata-tahoe start
 --basedir $HERE'. After that, the client node should be off and running. The
 first thing it will do is connect to the introducer and introduce itself to
 all other nodes on the grid. You can follow its progress by looking at the
 $HERE/twistd.log file.

 To actually use the client, enable the web interface by writing a port
 number (like "8080") into a file named $HERE/webport and then restarting the
 node with 'allmydata-tahoe restart --basedir $HERE'. This will prompt the
 client node to run a webserver on the desired port, through which you can
 view, upload, download, and delete files.

 A client node directory can also be created without installing the code
 first. Just use 'make create-client', and a new directory named 'CLIENTDIR'
 will be created inside the top of the source tree. Copy the relevant .furl
 files in, set the webport, then start the node by using 'make start-client'.
 To stop it again, use 'make stop-client'. Similar makefile targets exist for
 making and running an introducer node.

 There is a public grid available for testing. Look at the wiki page
 (http://allmydata.org) for the necessary .furl data.