source: README.PACKAGE_MANAGEMENT@ c6c2d89

TITLE : Package management in jhalfs
BY    : Pierre Labastie (work in progress)
$Id$

1. INTRODUCTION:

      There are several hints discussing package management for LFS, but
  nothing under jhalfs. There used to be a patch for PACO that I cannot
  find now. This is a modification ("DESTDIR install" automation), which
  allows to use a package manager inside jhalfs. I hope it is flexible enough
  to support several package managers, at least among those who use DESTDIR
  install. My initial implementation used dpkg, from Debian, in a very
  crude way (Debian has a sophisticated package management system, which
  I have not tried to use here). There is also a port to Pacman from
  Arch Linux (http://www.archlinux.org). I am sorry to say I have (almost)
  no experience with rpm, so I cannot tell whether it would fit.

2. OVERVIEW OF THE SYSTEM:

      Presently, package management is only available for LFS. I plan to
  upgrade BLFS tools, but nothing usable right now. I have not attempted
  to adapt this tool for the other flavours of LFS.

      To use package management, you need to create the required files in
  the pkgmngt directory (see below), and to select "package management" in
  the build settings. Note that this is incompatible with creating an SBU
  and usage report.

3. DETAILS OF OPERATION:

      This system performs basically a "DESTDIR install" for all pages
  in chapter 6, 7 and 8 of the book. The name of the DESTDIR directory is the
  same as the one of the executed script. The path to this directory is
  made available to the scriplets through the PKG_DEST variable.
      The XSL stylesheet used for generating the scriptlets, automatically
  adds DESTDIR install instructions when "package management" is selected.
  Also all the paths beginning with " /" or ">/" (absolute paths) are prepended
  with $PKG_DEST. This has the default that you might want to move
  files to non existent directories. There is no simple way to automatically
  create those directories, because you have sometimes to use the full path
  (instructions of the form `cp file dir') and sometimes only the dirname
  (instructions of the form `cp file1 file2'). So the XSL stylesheet
  creates a reasonable subset of the FHS hierarchy into the destination
  directory. Empty directories are then removed before packing the
  binary package.
      In order to use the package manager, it has to be installed at the end of
  chapter 5 (temporary installation in /tools) and chapter 6 (final install).
  Furthermore, the administrative files and directories have to be created
  during the `Creating Directories' and `Creating Essential Files' stages.
  For all this, the user has to supply a file in docbook XML format, with
  the necessary instructions and enough information to download the tarball.
  This file should reside in the `pkgmngt' directory and be named
  `packageManager.xml'. A template named `packageManager.xml.template' is
  provided in the `pkgmngt' subdirectory. There are also two XML files for
  dpkg and pacman, respectively `packageManager.xml.dpkg' and
  `packageManager.xml.pacman', that you can copy to `packageManager.xml'.
  They are not updated often, so the versions used can be rather old.
      The last thing to do is to tell how to use the package manager. When
  the binary package is ready, the scriptlets call a shell function named
  `packInstall', which should pack the binary package and install it on the
  system. Note that nothing has been done to manage configuration files, 
  which are ususally treated specially by package managers: depending on
  the book layout, it is sometimes possible to create those files afterwards,
  and sometimes not, which means that you have to check them after each
  upgrade. The user has to write his own `packInstall' function. The shell
  function should be defined in a file named `packInstall.sh', residing in
  the `pkgmngt' directory. A template is provided, as well as two example
  scripts for dpkg and pacman. Note that, due to the way pacman checks the
  available space on disk, the root directory in chroot must be a mount point,
  otherwise the installation of packages fails.