slackware-current/source/d/slacktrack/OVERVIEW
Patrick J Volkerding 75a4a592e5 Slackware 13.37
Mon Apr 25 13:37:00 UTC 2011
Slackware 13.37 x86_64 stable is released!

Thanks to everyone who pitched in on this release: the Slackware team,
the folks producing upstream code, and linuxquestions.org for providing
a great forum for collaboration and testing.

The ISOs are off to be replicated, a 6 CD-ROM 32-bit set and a
dual-sided
32-bit/64-bit x86/x86_64 DVD.  Please consider supporting the Slackware
project by picking up a copy from store.slackware.com.  We're taking
pre-orders now, and offer a discount if you sign up for a subscription.

As always, thanks to the Slackware community for testing, suggestions,
and feedback.  :-)

Have fun!
2018-05-31 22:45:18 +02:00

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##############################################################################
# Document: OVERVIEW
# Purpose : Provide an overview of the Slackware package system incorporating
# the use of 'slacktrack'
# Please note that this is *not* a guide to the use of slacktrack;
# the man page and SlackBuild scripts in the 'examples' directory
# aim to fulfill that requirement.
# Date....: 15-May-2009
# Author..: Stuart Winter <mozes@slackware.com>
# Homepage: http://www.slackware.com/~mozes
##############################################################################
CONTENTS:
---------
1.0 Preamble
2.0 Slackware packages
2.0.1 Format of official Slackware packages
2.0.1.1 Package names
2.0.1.2 Version numbers
2.0.1.3 Architectures
2.0.1.4 Build numbers
2.1 An overview of the creation of official Slackware packages
2.1.1 'Clean' and 'dirty' builds
2.1.1.1 Clean builds
2.1.1.2 Dirty builds
2.1.1 SlackBuild and .build scripts
2.1.1.2 SlackBuild scripts
2.1.1.3 .build scripts
2.2 slacktrack in the scheme of things
2.2.1 Using slacktrack with official .build scripts
2.2.2 Writing your own .build scripts for slacktrack
2.2.2.1 Making use of slacktrack's environment variables
3.0 slacktrack in operation
3.1 How slacktrack finds which files have been installed
3.1.1 installwatch's author
4.0 Example scripts
4.0.1 non-slackware example build scripts
4.0.2 slackware example wrapper build scripts
5.0 Known problems/features of slacktrack
6.0 New features
7.0 Licence
1.0 Preamble
---------
I used to work for a company that provided web hosting and shell accounts.
When I started there were a number of shell servers all running various
releases of RedHat Linux, in various states of repair. I managed to convince
the management to let me try Slackware on there instead because I have a much
stronger understanding of how to maintain and build server using the
Slackware distribution. This trial went well and within a few months all
servers were converted to Slackware version 8.1.
In order to ease the speed of installation (and to prevent against
forgetting to install or configure something critical), I wrote a
set of post installation scripts that upgraded Slackware packages,
configured numerous config files and copied pre-compiled software
(such as courier IMAP) onto the new system.
For other software that I could not simply copy, I'd compile it on the
new server.
However, it soon became clear that due to security updates and so on,
it became incredibly time consuming (not to mention seriously boring)
to compile PHP, Apache and so on on every server.
At this point, I began to investigate how to create packages for Slackware.
2.0 Slackware packages
------------------
The Slackware Linux distribution consists of a variety of 'packages'
that make up the distribution.
Traditionally, all packages are in '.tgz' format (a gzipped tar archive).
Starting with Slackware v13, new compression formats are supported which
are represented by three additional file extensions:
.tgz - Gzip
.tbz - Bzip2
.tlz - LZMA
.txz - XZ
In this document, we use the file extension '.t?z' to represent
one of the above file formats.
Once you have initially installed Slackware from the installer screen,
you have the facilities to install, remove or upgrade new or existing
packages using the package management tools:
installpkg <package.t?z> - install 'package.t?z'
upgradepkg <package.t?z> - upgrade existing 'package' with the
new version specified at the command line.
removepkg <package> - remove specified package
Whilst the Slackware package system is not especially feature rich,
Slackware's user base (including me) like it because it is simple.
If we want to write our own package utilities then we can easily do so
by examining the existing package tools and querying and amending the
package database (text files).
2.0.1 Format of official Slackware packages
-------------------------------------
In Slackware 8.1 and up, each package file is named as follows:
packagename-version-architecture-buildnumber.t?z
2.0.1.1 Package names
-------------
The package name is either the name of the single program
or the name of a collection of utilities that fall under
a single umbrella.
For example:
autoconf-2.54-noarch-1.tgz
That is the name of the autoconf package I have on my
Slackware 8.1 box.
'autoconf' is the name of the the entire collection of
binaries and associated documents that are extracted from
the autoconf source distribution archive.
However, if we consider another example:
tcpip-0.17-i386-15.tgz
There is no single piece of software called 'tcpip'.
This package contains a number of associated utilities
written by different authors but bundled into one single
'package'.
2.0.1.2 Version numbers
---------------
If the package is the name of a particular piece of software
such as 'autoconf' from the example above, then the version
number represents the version number that its authors distribute.
If the package is a 'bundle' such as 'tcpip' then the version
number increases as and when you add a new piece of software to
the package, or upgrade a particular piece of major software
contained within the package.
For example, with 'tcpip' above, the 0.17 refers to the version of
Linux Netkit. However, there are other programs included within
the Slackware tcpip package that are not part of 'Linux netkit'.
2.0.1.3 Architectures
-------------
The architecture is just that -- it tells you which architecture
the package is for.
The current values in use are:
----- [ Official Slackware architecures ]
noarch - Architecture independent files such as config files
i386 - packages for the x86 (Slackware v8.1 & 9)
i486 - packages for the x86 (Slackware 9.1+)
i586 - packages for the x86
s390 - packages for the IBM s/390 mainframe
Note: Whilst Slackware v10 is primarily built for i486, you may
find that there are some packages whose architecture versions
are higher than i486. This is for two reasons:
[a] There is no source for the package - it is a repackaged
binary distribution (SUN's j2sdk is an example).
[b] The package is not required or otherwise not suitable for
earlier revisions of the architecture (this is especially
the true with ARM and SPARC).
----- [ Unofficial ports of Slackware ]
arm - packages for the ARM architecture
sparc - packages for the SUN Sparc architecture
powerpc - packages for the PowerPC architecture
2.0.1.4 Build numbers
-------------
A build number suplements the version number and is changed
when the *package maintainer* makes a change to the package but
the original source code and version number remains the same.
For example, I build a package of 'foo' version 0.14 for the
sparc. I have never built this package before, thus it becomes
foo-0.14-sparc-1.tgz
However, I realise that I haven't configured
the 'bar' parameter correctly in /etc/foo.conf. I fix it
and re-build the package. The package is now named
foo-0.14-sparc-2.tgz
2.1 An overview of the creation of official Slackware packages
-----------------------------------------------------------
This section gives a brief introduction of the two methods of
used when building the official Slackware packages.
2.1.1 'Clean' and 'dirty' builds
--------------------------
I am assuming the reader has some experience with Makefiles
and has compiled and installed a number of software packages.
2.1.1.1 Clean builds
------------
I term a 'clean' package one where you can specify a variable
to the 'make install' which contains the directory you wish to install
the package in, rather than installing it properly over the root file system.
For example:
# ./configure --prefix=/usr --sysconfdir=/etc
# make
# make install DESTDIR=/tmp/package-foo
With a 'Makefile' that honours the DESTDIR variable, this will
install the whole package into /tmp/package-foo. This directory
effectively is the 'root' directory '/' as far as the Makefile
is concerned.
From here you can use the Slackware 'makepkg' program and build
a package.
This is by far the safest and most preferred method by all
users that make packages.
You will find that DESTDIR is called prefix, TOPDIR and other names;
you need to examine the Makefile scripts in order to determine whether
it contains this functionality and if it does, then discover what
the variable name is.
2.1.1.2 Dirty builds
------------
A 'dirty' build is the name I give to source distribution archives
whose Makefile scripts do not have any provisioning to install
in an alternate directory other than root.
For these type of builds, you will typically do:
# ./configure --prefix=/usr --sysconfdir=/etc
# make
# make install
The package will then be installed on the root filesystem.
So how do you know what files were installed where and
even if you did, how do you pull all these files together in order
to run makepkg over them ?
That's the purpose of slacktrack! :-)
2.1.1 SlackBuild and .build scripts
-----------------------------
Slackware has a number of packages by a great number of authors.
Some of the packages's source Makefiles honour a DESTDIR type
variable but others do not.
2.1.1.2 SlackBuild scripts
------------------
SlackBuild scripts can be 'interesting'. They are
scripts that install into a 'clean' environment (usually /tmp).
Some of the scripts follow the make install DESTDIR=
style, if the Makefile permits.
Others have a 'framework' or 'controller tarball' which is
a _packagename.t?z (note the prefixing underscore).
The SlackBuild script uses the Slackware 'explodepkg' script
to untar the contents of the _.t?z into the /tmp-package<name>
directory.
Slackbuild then runs 'make' to compile the binaries
and libraries, but then uses the 'cat' program such as:
# cat foobar > /tmp/package-foobar/usr/bin/foobar
By using 'cat', the *new* version of 'foobar' retains
the original permissions and ownerships that are in the
controller tar ball.
However, you may be wondering how, if the package does not
have a facility to install into somewhere other than root,
do we get the file names and permissions for the
controller _.t?z in the first place.
The answer is simple:
[a] find all files on the file system and dump to a file.
[b] compile and install the software
[c] find all files on the file system and compare the file
produced by the first 'find'. After a little pruning, you
have the list of files for the controller tar ball.
2.1.1.3 .build scripts
---------------
For those software distributions whose Makefile does not hounour
the DESTDIR type system, there are Slackware's .build scripts.
These scripts literally ./configure ; make ; make install
and copy docs and other goodies into the root file system.
One of the problems with these scripts is that they are
often incomplete -- they build and install the package but
do not gzip the man pages or strip the binaries and libraries;
this is done manually afterwards.
*These* are the scripts that slacktrack and altertrack were
written for.
* Note: Whilst some software's Makefiles may appear to honour
the DESTDIR variable, the Makefile *may* be broken which can
result in files missing or corrupt within your new package.
For example: I built Apache v2.0.48 and built a package using
make install DESTDIR. However, a problem exists in that some of
the Perl scripts it installs have *temporary build paths*
hard coded into the resulting scripts.
This is why you *may* find a .build instead of a SlackBuild
script within Slackware's source tree.
However, the primary reason is because the build script just
hasn't been updated to make use of DESTDIR. *
2.2 slacktrack in the scheme of things
----------------------------------
I follow Slackware-current quite closly. Often I want to
'back port' a -current package to an earlier release of Slackware .
I can't simply upgrade with -current's package because it was
compiled for a newer GLIBC than Slackware 8.1's, for example.
For packages that use a 'clean' 'SlackBuild' script, this is
an easy job -- I simply run 'SlackBuild' on an 8.1 box.
However, for .build scripts, I needed a way of building packages
using Slackware's .build scripts.
I found a great program called 'CheckInstall' which fulfilled most of my
requirements. However, as time went on and I started building
more of Slackware's packages and writing my own build scripts, I found
that checkinstall was lacking some features that I required.
At this time I was also considering porting Slackware to run on
the ARM architecture and helping with the Splack (Slackware on SPARC project),
and therefore wanted a robust program that can deal with every .build script
I threw at it, and if it can't handle it, I needed to be able to make modifications.
The easiest way of doing this was to write my own script; thus
'slacktrack' was born.
slacktrack is based on the *idea* behind 'CheckInstall', but uses
only my own code (and contributions from other users), and only contains
Slackware-specific facilities -- it can not build Debian or RedHat packages
and never will.
slacktrack does not have all of the facilities of CheckInstall either,
but then these are not required for building Slackware packages
from .build scripts.
Also, slacktrack only works with 'official' Slackware directory locations
and /usr/local.
For example, if your make install installs binaries in /opt/packagename/bin
and the man pages in anywhere other than /usr/man or /usr/local/man, then
slacktrack's relevant options (eg stripping libs, bins, gzman) will
not detect them.
2.2.1 Using slacktrack with official .build scripts
---------------------------------------------
Building a replicar Slackware package from a .build script is
typically fairly trivial with slacktrack.
If we wanted to build slackware-9.1's elvis, we could do
# cd slackware/slackware-9.1/source/a/elvis
# chmod 755 elvis.build
# slacktrack -jefkzp "elvis-2.1-i386-2.tgz" ./elvis.build
The resulting package (by default) be stored in
/tmp/built-slackwarepackages/
As already mentioned, some of the Slackware .build scripts
are incomplete with regard to gzipping man pages, stripping binaries
and so on -- fetchmail.build is one of them.
Therefore you can specify various options to slacktrack that
will take care of this for you.
The options in the example above :
j - compress libraries
e - chown root:bin /bin,/sbin,/usr/bin,/usr/sbin directories
f - chown root:bin files in the binary dirs listed above
k - strip binaries found in the binary dirs listed above
z - gzip man pages
p - the resulting Slackware package .t?z name
The way I re-create the packages is to build a 'trackbuild' script that
launches slacktrack with the required options and the name
of the Slackware .build script. You can find examples of such
scripts within the docs directory after installing slacktrack:
/usr/doc/slacktrack*/buildscript-examples/
You will also find that in Slackware versions 12.0 and upwards,
the .build scripts are accompanied by 'trackbuild' scripts because
slacktrack is used by the Slackware team to produce the packages.
2.2.2 Writing your own .build scripts for slacktrack
----------------------------------------------
There isn't any specific that you have to do to write a build
script for use with slacktrack -- the script name specified to
slacktrack doesn't even have to be a script - it can be a binary -
as long as it is executable, it is acceptable.
You can see some of my own build scripts that I have written
for use with slacktrack by looking in the documents directory
after installing slacktrack:
/usr/doc/slacktrack*/buildscript-examples/
2.2.2.1 Making use of slacktrack's environment variables
-------------------------------------------------
slacktrack exports two environment variables:
SLACKTRACKFAKEROOT and SLACKTRACKSCRATCHDIR
SLACKTRACKFAKEROOT:
````````````````````
The purpose of this to allow your .build script to access the
'root' directory of the resulting package.
There are two scenarios where you may want to use this
variable:
1. During the build:
The reason you may wish to do this is to pre-populate
the package with files that you may not wish to place directly
onto the root filesystem.
The package contents will only appear inside this directory
once your build script has finished, and slacktrack has determined
what to put into this directory.
In previous slacktrack versions which used a pseudo-root filesystem
(where the package contents were populated *during* the build), this
made sense, but in slacktrack v2.00, it is unlikely that you'd want
to use this vairable from the build script.
2. Post-build -- cleanups after the build:
The most likely use of this script is to perform package cleanup
tasks after the build. This is mainly to perform tasks that slacktrack
does not handle itself - such as deleting known files/directories that
creep into packages (due to a system daemon such as CUPS), or setting
some file and directory permissions.
An example post build script is below.
A post build script can be specified by slacktrack's -R option:
# Incase you had CUPS running:
rm -rf etc/cups etc/printcap
# crond:
rm -rf var/spool/cron
rmdir var/spool
# perllocal.pod files don't belong in packages.
# SGMLSPL creates this:
find . -name perllocal.pod -print0 | xargs -0 rm -f
# Some doc dirs have attracted setuid.
# We don't need setuid for anything in this package:
chmod -R a-s .
SLACKTRACKSCRATCHDIR:
`````````````````````
The purpose of this variable is to provide some temporary
space to untar your source archives and so on. slacktrack
will manage the creation and deletion of this directory.
For example:
# cd ${SLACKTRACKSCRATCHDIR}
# tar zxvvf ${ORIGPATH}/source/foobar.tar.gz
You can see in some of the example 'non-slackware' scripts
how I have used these variables
3.0 slacktrack in operation
-----------------------
The basic event flow is as follows:
[1] Parse command line arguments
-> Check they are OK, if not bomb out
[2] Launch the supplied build script
[3] Run any specified functions (eg gzman, strip bins, chowns) over the
package 'root' directory and contents
[4] Run Slackware's 'makepkg' program over the package contents
[5] Move the .t?z to the specified build store path
[6] Scan for any hard links that may be in the package
-> If any found, alert the user on screen and also
log to a packagename.hardlinks.log file in the build store path
The slacktrack shell script is fairly simple and well commented; it should be
relatively easy for anybody who understands bash to quickly comprehend what
is happening and why.
3.1 How slacktrack finds which files have been installed
----------------------------------------------------
In order to track the files and directories that have been installed
or changed, slacktrack follows this ordered process:
[1] Scans a pre-set list of directories on the filesystem and
logs the contents.
[2] Launches build script which installs the package onto the
filesystem
[3] Scans the filesystem once again
[4] Compares the differences in the before and after snapshots
[5] Copies the differences into a 'package root directory' and
runs makepkg over them.
In slacktrack version 1, we used 'installwatch' which overloaded
some of glibc's filesystem calls, creating new files and directories
into a pseudo-root filesystem, avoiding the need to install onto
the host's filesystem (and also allowing to build as a non-root user).
However, this library is ill maintained and even in the early days
when it worked well, it still had problems and workarounds were required.
4.0 Example scripts
---------------
Included with the slacktrack binary distribution are a number of example
scripts that hopefully should provide you with a basis of how to use slacktrack
to build from 'dirty' source distributions.
The examples are bundled in the documentation directory available
after installing slacktrack:
/usr/doc/slacktrack*/buildscript-examples/
5.0 Known problems/features of slacktrack
-------------------------------------
Current problems:
[1] slacktrack doesn't have sufficient error checking.
I'm in two minds about *where* to put error checking, you see.
Do I go no further if the supplied build script exits with a non-zero
value?
No, that's a bad idea because what if you didn't write the build script?
it might be one of these qmail type binary installer programs that
you can't (easily without hacking the source) fix. The author may
have their own systems, and the program exits with a value that their
own controller script recognises as non-failure.
What should I do if makepkg has failed? You see it on screen
and in the logs anyway, plus makepkg is one of the last things
that slacktrack calls -- how can you recover?
That said, version 1.03 now has some error handling. There's still
not enough though, imo.
[2] No support for a default config file
I don't see the point. Each .build script is different
and although I typically use the same options to slacktrack
for most of my build scripts, I don't see why I'd need a
config file just to save 4 bytes or so in a trackbuild wrapper :-)
6.0 New features
-------------
See the TODO file in the docs directory.
If you have any specific features you would like to see
included, or have found any bugs, please
email me <mozes@slackware.com>
7.0 Licence
-------
slacktrack is distributed under BSD Licence.