''Attention: this page is for Tahoe-LAFS developers. If you are not a Tahoe-LAFS developer, then the page you want is [http://tahoe-lafs.org/trac/tahoe-lafs/browser/trunk/docs/quickstart.rst quickstart.rst].''

see also wiki:OSPackages

= Packaging =

== quickstart.rst ==

The setup method that we offer to people when we don't know what platform they are setting up on or what level of expertise they have is "the quickstart.rst method". This method starts by telling them to go to http://tahoe-lafs.org and follow "the quickstart instructions" link.
 * quickstart.rst is intended to be as platform-independent as possible.
 * quickstart.rst should ''not'' instruct the user to install any dependency if the build system could instead satisfy that dependency automatically (currently, as of 2011-08-16, the only dependency that can't be satisfied automatically for a build from trunk is Python).
 * quickstart.rst is intended to be as simple as possible. Options (you can do it this way or that way as you prefer) or branches (if you are in this situation do this, else do that) are strongly discouraged from being written into quickstart.rst. If at all possible, please move those to AdvancedInstall.

The goal is to start with a bare OS and a network connection (no Python, no compiler) and get to a working {{{./bin/tahoe}}} by downloading a few things and running {{{setup.py build}}} (which downloads the rest).

=== binary .egg's of dependency native-code packages ===

For quickstart.rst to work on your platform there ''must'' exist a binary .egg for your platform of every dependency that has a native-code extension module, which are listed in the columns of [http://tahoe-lafs.org/source/tahoe-lafs/deps/tahoe-lafs-dep-eggs/README.html this table]. If there is no binary .egg available of one of those packages for a given platform then this is a bug which prevents quickstart.rst from working on that platform. (Note: if you already had that Python package installed on your system then you would be able to setup Tahoe-LAFS even if there is no binary egg of that Python package available, e.g. if you manually installed the package already or if you installed the package already using an operating system packaging tool like apt-get. Nonetheless, since we can't rely on the user having done that and since quickstart.rst cannot instruct the user to do that -- see the section about quickstart.rst above -- then the absence of a binary .egg of a dependency for a platform is a bug preventing quickstart.rst from working on that platform.)

==== Creating a binary egg for !PyCrypto ====

!PyCrypto's {{{setup.py}}} does not support setuptools, so the {{{bdist_egg}}} target is not available out of the box. To build an egg, use the following command:

{{{$ python -c "import setuptools; execfile('setup.py')" bdist_egg}}}

Detailed instructions for building a !PyCrypto egg on Windows: HowtoBuildPyCryptoOnWindows.

== AdvancedInstall ==

An alternative method to quickstart.rst is AdvancedInstall. This method would be appropriate for people who prefer for the setup to be done differently than the way quickstart.rst works. It is also the fallback for people who have tried quickstart.rst and it didn't work (although the fact that quickstart.rst didn't work should also be treated as a build process bug even if falling back to AdvancedInstall allows the user to proceed).

== Pre-built Debian packages ==

See DownloadDebianPackages.

== As shipped by Ubuntu ==

Tahoe-LAFS comes with Ubuntu. See http://packages.ubuntu.com/lucid/tahoe-lafs .


== Desiderata ==

We want to package Tahoe-LAFS for people to download and use and we want to use
3rd-party libraries. The following are our current desiderata:

 * For certain deployment targets (namely, recent Debian and recent or Long-Term Support Ubuntu), our Debian packagers produce a Tahoe-LAFS binary package for
   that platform, and upload it to the standard apt repositories. Our users can install that package by running
   {{{
     sudo apt-get install tahoe-lafs
   }}}
   and it will Just Work. That is, users don't have to manually satisfy any dependencies by building other packages.

For libraries that Tahoe-LAFS uses, we have these desiderata:

 * We use the source code as it is written by upstream. That is: no patching
   required.

 * Use it as it is packaged by upstream. That is: we prefer to get a copy of
   the source code of the package as upstream prefers to distribute such
   source code, rather than by pulling from their revision control tool or so
   on.  (But we strongly prefer source packages to binary.)

 * The user doesn't have to manually resolve any conflicts (this means that
   we either have to automatically use a 3rd-party library if it is already
   installed or else we have to automatically force Tahoe-LAFS to use the copy
   that it came bundled with).

 * Make it convenient for someone to use other versions of the packages that
   we use e.g. system-wide packages or newer or alternate versions, etc..

 * Bundle required libraries with the Tahoe-LAFS distribution so that if someone
   downloads the distribution, moves to a desert island without a net
   connection, and then installs, it works.


== setuptools ==

We use a Python packaging tool named [http://pypi.python.org/pypi/setuptools setuptools] (actually a fork of it named [http://tahoe-lafs.org/trac/zetuptoolz zetuptoolz]).

Advantages:

 * management of dependencies (even on platforms that don't have a native package manager);  This is the important feature.

 * integration with the [http://pypi.python.org/pypi Python Package Index (PyPI)] -- with setuptools we can update the [http://pypi.python.org/pypi/allmydata-tahoe allmydata-tahoe metadata at PyPI] automatically, and also upload packages to be distributed from PyPI

 * for hackers who like setuptools, this makes using Tahoe convenient and pleasant for them

 * it allows "build/configure/package/distribute/test/develop" code written in the Make language to be replaced with code written in Python. One specific instance of this is {{{./setup.py test}}} which runs the unit tests. (We still have a makefile, but it is possible to build and develop Tahoe-LAFS without using it.)

Disadvantages:

 * setuptools has many bugs and is poorly maintained.

 * these bugs affect Tahoe-LAFS disproportionately because it has more, and more complicated, dependencies than most Python packages. We currently have [[TicketQuery(status!=closed&keywords~=setuptools, count)]] open setuptools-related tickets ([query:status!=closed&keywords~=setuptools full list]) and have closed [[TicketQuery(status=closed&keywords~=setuptools, count)]] such tickets ([query:status=closed&keywords~=setuptools full list]). (These counts may be a bit high because of duplicates and non-bugs, but they're indicative of the problem.)

 * maintaining our fork (which is necessary to avoid some of the bugs) takes up developer time and mental bandwidth that would be more productively spent on Tahoe-LAFS itself.

 * even when working as designed, setuptools has some serious problems. For example, people who package Tahoe for OS distributions generally dislike very much its behaviour of automatically downloading dependencies from random websites (however convenient something like that would be if it were optional and designed properly).


== Build System Theory ==

See BuildSystemTheory for a discussion of the ways in which Tahoe-LAFS is built, the conflicting goals of these ways, and (eventually) a plan to be able to meet these multiple goals.