tahoe-lafs/README

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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 almost certainly get them through your standard package
manager. If you are running Mac OS X then 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
* 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/
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 a debian
package named 'allmydata-tahoe', 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/", which you can then add to your PYTHONPATH .
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 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.