wiki:Packaging

Version 18 (modified by zooko, at 2010-09-18T09:32:11Z) (diff)

explain my strategy about quickstart.html+binary-eggs vs. AdvancedInstall

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/source/tahoe-lafs/trunk/docs/quickstart.html .

Packaging

quickstart.html

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.html method". This method starts by giving them a link to http://tahoe-lafs.org/source/tahoe-lafs/trunk/docs/quickstart.html .

  • The quickstart.html is intended to be as platform-independent as possible--the only mention of a specific platform is that the dependency on "pywin32" can't be satisfied automatically (#142).
  • The quickstart.html should not instruct the user to install any dependency if the build system could instead satisfy that dependency automatically (currently, as of 2010-09-18, the only dependencies that can't be satisfied automatically are python, and pywin32 which is needed only on Windows).
  • The quickstart.html 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.html. If at all possible, please move those to AdvancedInstall.

binary .egg's of dependency native-code packages

For quickstart.html to work on your platform there must exist a binary .egg for your platform of every dependency which has a native-code extension module. Currently those are: pycryptopp, zfec, pywin32, and PyCrypto?. If there is not a binary .egg available of one of those packages for a given platform then this is a bug which prevents quickstart.html 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 not a 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.html cannot instruct the user to do that (see the section about quickstart.html above), then the absence of a binary .egg of a dependency for a platform is a bug preventing quickstart.html from working on that platform.

AdvancedInstall

Another installation method, alternative to quickstart.html, is AdvancedInstall. This method would be appropriate for people who prefer for the setup to be done differently than the way quickstart.html works. It is also the fallback for people who have tried quickstart.html and it didn't work (although the fact that quickstart.html 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), we produce a Tahoe-LAFS binary package for that platform, ship that package to a user using that platform, they can install that package, and it will work. That is: user doesn't have to manually satisfy any dependencies by building other packages.

This is accomplished by adding the following clause to /etc/apt/sources.list and then running apt-get install allmydata-tahoe:

deb http://allmydata.org/debian  $DIST  main tahoe

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 setuptools.

Advantages:

  • management of dependencies (even on platforms that don't have a native package manager); This is the important feature.
  • for hackers who like setuptools, this makes using Tahoe convenient and pleasant for them

Possible advantages:

  • perhaps in the future we will replace "build/configure/package/distribute/test/develop" code written in the Make language with code written in Python; One specific instance of this is ./setup.py test which runs the unit tests