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<article>
  <title>FreeBSD Release Engineering for Third Party Software
    Packages</title>
  <articleinfo>
    <authorgroup>
      <author>
        <firstname>Steve</firstname>
        <surname>Price</surname>
        <affiliation>
          <address><email>steve@FreeBSD.org</email></address>
        </affiliation>
      </author>
    </authorgroup>

    <pubdate>$FreeBSD$</pubdate>

    <abstract>
      <para>This paper describes the approach used by the FreeBSD
        release engineering team to produce a high quality package set
        suitable for official FreeBSD release media.  This document is
        a work in progress, but eventually it will cover the process
        used to build a clean package set on the FreeBSD.org "Ports
        Cluster", how to configure any other set of machines as a
        ports cluster, how to split up the packages for the release
        media, and how to verify that a package set is
        consistent.</para>
    </abstract>

  </articleinfo>
  
  <!-- Introduction 

  <sect1 id="introduction">
    <title>Introduction</title>

    <para><emphasis>Coming Soon</emphasis></para>

  </sect1>

-->
  <sect1 id="portbuild">
    <title>Building packages from the Ports Collection</title>

    <para>The <ulink url="http://www.FreeBSD.org/ports">FreeBSD Ports
      collection</ulink> is a collection of over &os.numports;
      third-party software packages available for FreeBSD. The &a.portmgr;
      is responsible for maintaining a consistent ports tree that can be used
      to create the binary packages that accompany a given FreeBSD
      release.</para>
    
    <sect2>
      <title>The Ports Cluster</title>

      <para>In order to provide a consistent set of third-party
        packages for FreeBSD releases, every port is built in a
        separate chroot environment, starting with an empty
        <filename>/usr/local</filename> and
        <filename>/usr/X11R6</filename>. The requisite dependencies
        are installed as packages before the build proceeds. This
        enforces <emphasis>consistency</emphasis> in the package build
        process. By starting the package build in a pristine
        environment, we can assure that the package metadata (such as
        required dependencies) is accurate, and so we will never
        generate packages that might work on some systems and not on
        others depending on what software was previously
        installed.</para>
      
      <para>The <quote>Ports Cluster</quote> for the x86 architecture
        currently consists of a master node (Dual Pentium III 733Mhz)
        and 8 slave nodes (Pentium III 800Mhz) to do the actual
        package builds.  With this configuration, a complete package
        build takes over 24 hours.  These machines are co-located with
        the other FreeBSD Project equipment at Yahoo's corner of
        Exodus in Santa Clara, CA.</para>
      
      <para>The <quote>Ports Cluster</quote> for the Alpha
        architecture consists of 7 PWS 500A machines donated by Compaq
        and also co-located with Yahoo's facilities.</para>
    </sect2>
  </sect1>

  <sect1>
    <title>The Package Split</title>

    <para>For FreeBSD 4.4 over 4.1 gigabytes of packages were created.
      This causes a problem for CDROM distributions because we would
      like to ship as many packages as possible without making the
      user insert another disc to satisfy dependencies. The solution
      is to create <quote>clusters</quote> of like packages with
      similar dependencies and group these onto specific discs.  This
      section describes the software and methodology used to create
      those package sets for the official FreeBSD release
      discs.</para>

    <para>First off you'll need to get a copy of the tarball from the
      following URL :</para>

    <para><ulink
      url="http://people.freebsd.org/~steve/release-scripts.tgz"></ulink></para>

    <para>Copy thisc archive to a machine that has enough free HD
      space to hold 2 to 3 times the size of the package set that you
      wish to split.  The tarball will extract into the current
      working directory so make sure you've created one suitably named
      directory for the release you are working on.</para>

    <para>After you've extracted the files, you will notice the
      following files :</para>

    <variablelist>
      <varlistentry>
        <term><filename>config</filename></term>

        <listitem><para>This file contains the free space on each disc
          and whether packages, distfiles, or both are allowed on any
          given disc.  The first column is the disc name.  It must be
          of the form disc[0-9a-z].  Currently it is setup to allow
          for 10 discs (4 for the release set and 6 for the toolkit).
          There's an implied extra disc called scratch where all of
          the remaining distfiles/packages land if they don't fit
          elsewhere.  The second column can be either a 1 or 0 where 1
          says that it is okay to place packages on this disc.  The
          third column works the same way except that it controls
          whether distfiles are placed on this disc.  The last column
          denotes the number of bytes of free space on a
          disc.</para></listitem>
        </varlistentry>

      <varlistentry>
        <term><filename>doit.sh</filename></term>

        <listitem><para>This is the workhorse.  Once you have all the
          files in place and things properly configured this script
          directs the process of splitting packages.  Beware it is
          interactive so you need to keep an eye on it as it runs.
          More details on what happens in this script will
          follow.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><filename>scripts/checkdeps.pl</filename></term>

        <listitem><para>Makes sure all packages dependencies are
          satisfied given an INDEX file and a directory of
          packages.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><filename>scripts/oneshot.pl</filename></term>

        <listitem><para>This is where all the magic (and I use that
          term loosely as it is mostly just a brute force approach)
          happens.  Given a list of required packages for each disc
          and a set of packages/distfiles this is the script that
          places a package or distfile on a disc along with all of its
          dependencies.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><filename>scripts/print-cdrom-packages.sh</filename></term>

        <listitem><para>This file is a copy of
          <filename>src/release/scripts/print-cdrom-packages.sh</filename>
          from the release you are working on.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><filename>scripts/scrubindex.pl</filename></term>

        <listitem><para>This script removes lines from an INDEX file
          for packages that aren't present.  It also removes the
          XFree86 dependencies.  NOTE: you'll need to tweak the value
          of the xdep variable to make sure the version number is
          correct.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><filename>scripts/setup.sh</filename></term>

        <listitem><para>This is a helper script that I use on the
          bento cluster to grab a copy of the ports tree and the
          matching set of the packages/distfiles.</para></listitem>
      </varlistentry>
    </variablelist>

    <para>Here's a checklist of things you'll need to check or
      configure before going any further.</para>

    <orderedlist>
      <listitem><para>Edit <filename>config</filename> to denote the
        number of discs you have, their sizes, and whether you want
        them want to contain packages, distfiles, both, or
        neither.</para></listitem>

      <listitem><para>Make sure you remove the gen directory if
        there's an old one laying around.  This directory contains
        working files that will only be valid for the current
        split.</para></listitem>

      <listitem><para>On your first pass through a split it is best to
        fake the copying of packages and distfiles.  This will save
        both time and diskspace while you do a couple of trial runs to
        make sure things fit, etc.  In the
        <filename>scripts/oneshot.pl</filename> set the fake variable
        to 1 and instead of actually copying the files it will
        &man.touch.1; them.  Be sure you turn this off or set fake to
        0 before you give the resultant discs to the person that will
        be mastering the discs otherwise they'll get a directory full
        of zero-sized files.</para></listitem>

      <listitem><para>Make sure you have a recent copy of the
        <filename>print-cdrom-packages.sh</filename> and that it is
        from the correct release.</para></listitem>

      <listitem><para>Check to make sure the XFree86 dependency in
        <filename>scripts/scrubindex.pl</filename> has the correct
        version number.  You'll also need to make sure this value is
        correct in <filename>doit.sh</filename> as
        well.</para></listitem>
    </orderedlist>

    <para>Next you'll need to get a copy of the ports tree, packages,
      and distfiles from a recent build on the package cluster.  See
      the <filename>scripts/setup.sh</filename> for a working example
      but essentially here's what needs to be done.</para>

    <orderedlist>

      <listitem><para>Grab a copy of <filename>ports.tar.gz</filename>
        and extract it into the ports directory alongside
        <filename>doit.sh</filename> and the
        <Filename>scripts</filename> directory.</para></listitem>

      <listitem><para>Remove the packages/distfiles directories or
        symlinks.  Bento has these as symlinks and you'll have mixed
        results if you don't get rid of them before
        proceeding.</para></listitem>

      <listitem><para>Create a new ports/packages directory and copy
        the package set from the package building
        cluster.</para></listitem>

      <listitem><para>Create a new ports/distfiles directory and copy
        the distfiles from the package building cluster.  NOTE: if you
        don't want any distfiles simply create the directory and leave
        it empty.  This directory must be present even if it doesn't
        contain anything.</para></listitem>
    </orderedlist>

    <para>Now we're finally ready for the fun task of actually
      splitting the packages.  You start the processing by running
      <command>./doit.sh</command>.  The first time you run it here's
      what it does.</para>

    <orderedlist>
      <listitem><para>Create a list of the restricted (can't be on the
        master FTP site) ports.</para></listitem>

      <listitem><para>Asks you if you'd like to remove the restricted
        ports.  Most of the time you'll want to answer (y)es
        here.</para></listitem>

      <listitem><para>Create a list of the packages/distfiles that
        can't be put on the discs.</para></listitem>

      <listitem><para>Asks you if you'd like to remove the
        non-cdromable packages/distfiles.  Most of the time you'll
        want to answer (y)es here.</para></listitem>

      <listitem><para>Copies the INDEX from the ports directory to the
        gen directory.  In doing so it removes the lines for ports
        where the packages don't exist.  It also checks to make sure
        that all of the required dependency packages are
        present.</para></listitem>

      <listitem><para>Create a list of packages that are required on
        each disc.</para></listitem>

      <listitem><para>Asks you if you'd like to populate the discs.
        After populating each disc it will check for missing
        dependencies, scrub the INDEX file, and create the
        CHECKSUM.MD5 file.</para></listitem>

      <listitem><para>Check to make sure the required packages made it
        on each disc and gives you a summary of the sizes of each
        disc.</para></listitem>
    </orderedlist>

    <para>After going through this the first time if you are lucky
      enough that all of the required packages built and fit on each
      disc.  All you need to do is set fake to 0 in
      <Filename>scripts/oneshot.pl</filename> and re-run
      <command>./doit.sh</command>.  The second and subsequent times
      around it will skip steps 1-5 above.  If you want to re-run any
      of those steps refer to doit.sh for which files need to be
      removed to not short-circuit those steps.  If you want to repeat
      all of these steps then the easiest way is to <command>rm -rf
      gen</command>.</para>

    <para>Upon successful completion the packages/distfiles will be in
      the <filename>disc*</filename> directories and the leftover will
      be in the scratch directory.</para>

    <para>What to do if things go wrong?  Here's some common gotchas
      and workarounds.</para>

    <variablelist>
      <varlistentry>
        <term>Missing required packages</term>

        <listitem><para>This is a pretty common occurrence.  You'll
          either need to wait for a new set of packages where the
          missing packages were built or get someone to re-start the
          package build for you.  DO NOT attempt to build the missing
          packages on your own machine and add them into the fray.
          While you might be able to get away with this if you are
          extremely careful the vast majority of the time you'll miss
          some little detail and the simple process of adding a
          package could make hundreds of others come up mysteriously
          broken.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>Required packages won't fit</term>

        <listitem><para>This happens on occasion too and is relatively
          easy to fix.  Simply edit print-cdrom-packages.sh to move
          packages around until they fit.  Yes this is an iterative
          process and one of the reasons why you should enable fake in
          <filename>scripts/oneshot.pl</filename> until you've gotten
          things the way you want them.  Re-run
          <command>./doit.sh</command> after you made your
          adjustments.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>Required packages not on the right (or any) disc</term>

        <listitem><para>This usually means you didn't add them to
          <filename>print-cdrom-packages.sh</filename> or you put them
          on the wrong disc.  This script is the gospel by which this
          whole process determines where a package must be.  If you
          want to force a package to land on a particular disc this is
          the only way to ensure that it will
          happen.</para></listitem>
      </varlistentry>
    </variablelist>

    <para>If you get completely stuck and can't figure out why things
      are borked or how to fix them then email &a.steve; for
      assistance.</para>

  </sect1>

</article>
