piuparts README
---------------

Author: Lars Wirzenius 
Email: <liw@iki.fi>

After reading this README you probably also want to have a look
at the piuparts manpage, to learn about the available options.
But read this document first! 

== Introduction

piuparts is a tool for testing that .deb packages can be
installed, upgraded, and removed without problems. The
name, a variant of something suggested by Tollef Fog
Heen, is short for "package installation, upgrading, and
removal testing suite".

piuparts is licensed under the GNU General Public
License, version 2, or (at your option) any later version.


== How to use piuparts in 5 minutes

=== Basic Usage

Testing your packages with piuparts is as easy as typing at the
console prompt:

---- 
# piuparts sm_0.6-1_i386.deb
---- 

Note that in order to work, piuparts has to be executed as user
root, so you need to be logged as root or use 'sudo'.

This will create a sid chroot with debootstrap, where it'll test
your package.

If you want to test your package in another release, for example,
lenny, you can do so with:

---- 
# piuparts ./sm_0.6-1_i386.deb -d lenny
---- 

By default, this will read the first mirror from your
'/etc/apt/sources.list ' file. If you want to specify a different
mirror you can do it with the option '-m':

---- 
# piuparts ./sm_0.6-1_i386.deb -m http://ftp.de.debian.org/debian
---- 

It's possible to use -d more than once. For example, to do a first 
installation in stable, then upgrade to testing, then upgrade to 
unstable and then upgrade to the local package use this:

----
# piuparts -d stable -d testing -d unstable ./sm_0.6-1_i386.deb
----


=== Some tips

If you use piuparts on a regular basis, waiting for it to create
a chroot every time takes too much time, even if you are using a
local mirror or a caching tool such as approx. 

Piuparts has the option of using a tarball as the contents of the
initial chroot, instead of building a new one with debootstrap. A
easy way to use this option is use a tarball created with
pbuilder. If you are not a pbuilder user, you can create this
tarball with the command (again, as root):

---- 
# pbuilder create
---- 

then you only have to remember to update this tarball with:

---- 
# pbuilder update
---- 

To run piuparts using this tarball:

---- 
# piuparts -p ./sm_0.6-1_i386.deb
---- 

If you want to use your own pre-made tarball:

---- 
# piuparts --basetgz=/path/to/my/tarball.tgz ./sm_0.6-1_i386.deb
---- 

Piuparts also has the option of using a tarball as the contents
of the initial chroot, instead of building a new one with
pbuilder. You can save a tarball for later use with the '-s'
('--save') piuparts option. Some people like this, others prefer
to only have to maintain one tarball. Read the piuparts manpage
about the '-p', '-b' and '-s' options

piuparts has a manpage too.

=== Piuparts tests

By default, piuparts does two tests:

. Installation and purging test.
. Installation, upgrade and purging tests.

The first test installs the package in a minimal chroot, removes
it and purges it. The second test installs the current version in
the archive of the given packages, then upgrades to the new
version (deb files given to piuparts in the input), removes and
purges.

If you only want to perfom the first test, you can use the
option: '--no-upgrade-test'  

=== Testing packages in the config-files-remaining state

The --install-remove-install option modifies the three piuparts
tests in order to test package installation while config files
from a previous installation are remaining, but the package itself
was removed inbetween.
This exercises different code paths in the maintainer scripts.

. Installation and purging test: install, remove, install again and purge.
. Installation, upgrade and purging test: install the old version, remove, install the new version and purge.
. Distupgrade test: install the version from the first distribution, remove, distupgrade to the last distribution, install the new version.

=== Analyzing piuparts results

When piuparts finishes all the tests satisfactorily, you will get
these lines as final output:

---- 
0m39.5s INFO: PASS: All tests.
0m39.5s INFO: piuparts run ends.
---- 

Anyway, it is a good idea to read the whole log in order to
discover possible problems that did not stop the piuparts
execution.

If you do not get those lines, piuparts has failed during a test.
The latest lines should give you a pointer to the problem with
your package.

== Custom scripts with piuparts

You can specify several custom scripts to be run inside piuparts.
You have to store them in a directory and give it as argument to
piuparts: '--scriptsdir=/dir/with/the/scripts'
This option can be given multiple times. The scripts from all
directories will be merged together (and later ones may overwrite
earlier scripts with the same filename).

The script prefix determines in which step it is executed. You
can run several scripts in every step, they are run in
alphabetical order.

The scripts are run *inside* the piuparts chroot and only can be
shell scripts, if you want to run Python or Perl scripts, you
have to install Python or Perl. The chroot where piuparts is run
is minized and does not include Perl.

The variable PIUPARTS_OBJECTS is set to the packages currently
being tested (seperated by spaces, if applicable) or the .changes
file(s) being used.  So when running in master-slave mode, it
will be set to the (one) package being tested at a time.

Depending on the current test, the variable PIUPARTS_TEST is set
to
. 'install' (installation and purging test),
. 'upgrade' (installation, upgrade and purging tests) or
. 'distupgrade'.

During the 'upgrade' and 'distupgrade' tests, the variable
PIUPARTS_PHASE is set to one of the following values:
. 'install' while initially installing the packages from the repository,
. 'upgrade' when upgrading to the .debs,
. 'distupgrade' while reinstalling the packages after 'apt-get dist-upgrade' to ensure they were not removed accidently
During the 'install' test, the PIUPARTS_PHASE variable is set to
'install'.

The current distribution is available in the variable
PIUPARTS_DISTRIBUTION.

The following prefixes for scripts are recognized:

'post_setup_' - after the *setup* of the chroot is finished.
Before metadata of the chroot is recorded for later comparison.

'pre_test_' - at the beginning of each test. After metadata of
the chroot was recorded for later comparison.

'pre_install_' - before *installing* your package. Depending on
the test, this may be run multiple times. The PIUPARTS_TEST and
PIUPARTS_PHASE variables can be used to distinguish the cases.

'post_install_' - after *installing* your package and its
dependencies.  Depending on the test, this may be run multiple
times. The PIUPARTS_TEST and PIUPARTS_PHASE variables can be used
to distinguish the cases.

'pre_remove_' - before *removing* your package.

'post_remove_' - after *removing* your package.

'post_purge_' - after *purging* your package. Right before
comparing the chroot with the initially recorded metadata.

'pre_distupgrade_' - before *upgrading* the chroot to the *next
distribution*. The next distribution is available in the variable
PIUPARTS_DISTRIBUTION_NEXT.

'post_distupgrade_' - after *upgrading* the chroot to the *next
distribution*. The previous distribution is available in the
variable PIUPARTS_DISTRIBUTION_PREV.


=== Example custom scripts:

'$ cat post_install_numbers'
----
#!/bin/bash

number=`dpkg -l | wc -l`
echo "There are $number packages installed."
exit 0
----

'$ cat post_setup_package'
----
#!/bin/sh

echo "$PIUPARTS_OBJECT will now get tested."
exit 0
----


== Distributed testing

As part of the quality assurance effort of Debian, piuparts is
run on the Debian package archive. This requires a lot of
processing power, and so the work can be distributed over several
hosts.

There is one central machine, the master, and any number of slave
machines. Each slave machine connects to the master, via ssh, and
runs the piuparts-master program to report results of packages it
has tested already, and to get more work.

To set this up for yourself, the following steps should suffice:

. Pick a machine to run the master. It cannot be a chroot, but basically any real (or properly virtualized) Debian system is good enough.
. Install piuparts on it.
. Create an account for the master.
. Configure '/etc/piuparts/piuparts.conf' appropriately.
. Pick one or more slaves to run the slave. You can use the machine running the master also as a slave. Etch is fine, it can even be in a chroot.
. Install piuparts on it.
. Configure '/etc/piuparts/piuparts.conf' appropriately - if master and slave share the machine, they also share the config file.
. Create an account for the slave. This must be different from the master account.
. Create an ssh keypair for the slave. No passphrase.
. Add the slave's public key to the master's '.ssh/authorized_keys'
. Configure sudo on the slave machine to allow the slave account run '/usr/sbin/piuparts' as root without password (otherwise you'll be typing in a password all the time).
. Run '/usr/share/piuparts/piuparts-slave' on the slave accounts. Packages that are installed want to use '/dev/tty', so you can't do this from cron. Also, you'll want to keep an eye on what is happening, to catch runaway processes and stuff.
. The logs go into the master account, into subdirectories.

Please note that running piuparts this way is somewhat risky, to
say the least. There are security implications that you want to
consider. It's best to do it on machines that you don't mind
wiping clean at a moment's notice, and preferably so that they
don't have direct network access.


=== Distributed piuparts testing protocol

The slave machine and the piuparts-master program communicate
using a simplistic line based protocol. SSH takes care of
authentication, so there is nothing in the protocol for that. The
protocol is transaction based: the slave gives a command, the
master program responds.  Commands and responses can be simple (a
single line) or long (a status line plus additional data lines).
Simple commands and responses are of the following format:

    'keyword arg1 arg2 arg3 ... argN'

The keyword is a command or status code ("ok"), and it and the
arguments are separated by spaces. An argument may not contain a
space.

A long command or response is deduced from the context: certain
commands always include additional data, and certain commands
always get a long response, if successful (error responses are
always simple). The first line of a long command or response is
the same as for a simple one, the additional lines are prefixed
with a space, and followed by a line containing only a period.

A sample session (">>" indicates what the slave sends, "<<" what
the master responds with):

----                
<< hello
>> pass liwc 1.2.3-4
>>  The piuparts
>>  log file comes
>>  here
>> .
<< ok
>> reserve
<< ok vorbisgain 2.3-4
----

Here the slave first reports a successful test of package liwc,
version 1.2.3-4, and sends the piuparts log file for it. Then it
reserves a new package to test and the master gives it
vorbisgain, version 2.3-4.

The communication always starts with the master saying "hello".
The slave shall not speak until the master has spoken.

Commands and responses in this protocol:

----                
Command: reserve
Success: ok <packagename> <packageversion>
Failure: error
----                    
Slave asks master to reserve a package (a particular version of
it) for the slave to test.  The slave may reserve any number of
packages to test. If the transaction fails, there are no more
packages to test, and the slave should disconnect, wait some time
and try again.

---- 
Command: unreserve <packagename> <packageversion>
Success: ok
---- 

Slave informs master it cannot test the desired version of a
package (perhaps it went away from the mirror?).

---- 
Command: pass <packagename> <packageversion>
          log file contents
         .
Success: ok
---- 

Slave reports that it has tested a particular version of a
package and that the package passed all tests. Master records
this and stores the log file somewhere suitable.

---- 
Command: fail <packagename> <packageversion>
          log file contents
         .
Success: ok
---- 

Same as "pass", but package failed one or more tests.

---- 
Command: untestable <packagename> <packageversion>
          log file contents
         .
Success: ok
---- 

Slave reports that a particular package is untestable, possibly
because it insists on interacting with the user.

----
Command: status
Success: ok <package-state>=<count> <package-state>=<count>...
----
Slave asks master to report the number of packages in all
different states. The "status" command should only be issued
after all "pass" and "fail" commands.

In all cases, if the master cannot respond with "ok" (e.g.,
because of a disk error storing a log file), it aborts and the
connection fails. The slave may only assume the command has
succeeded if the master responds with "ok".

The master may likewise abort, without an error message, if the
slave sends garbage, or sends too much data.


=== piuparts.conf configuration file

piuparts-master, piuparts-slave and piuparts-report share the
configuration file '/etc/piuparts/piuparts.conf'. The syntax is
defined by the Python ConfigParser class, and is, briefly, like
this:
----
    [master]
    foo = bar
---- 

==== global configuration

These settings have to be placed in the [global] section and are
used for all further sections.

* "sections" defaults to sid and defines which sections should be processed in master-slave mode. Each section defined here has to have a section with the section specific settings explained below. The first section defined should always be sid, because the data from first section a package is in is used for the source package html report.

* "master-host" is the host where the master exists. The slave will give this host to ssh. This option is mandatory.

* "master-user" is the username of the master. The slave will log in using this username. This option is mandatory.

* "master-directory" is the directory where the master keeps its files. Can be relative to the master's home directory.

* "master-command" is the command to run on master-host to start the master. When the master has been installed from the Debian package, the command is 'python /usr/share/piuparts/piuparts-master'.  The section name will be given as a command line argument to this command.

* "idle-sleep" is the length of time the slave should wait before querying the master again if the master didn't have any new packages to test. In seconds, so a value of 300 would mean five minutes, and that seems to be a good value when there are fairly few slaves per master. The default is 300 seconds.

* "max-tgz-age" is used to specify the maximum age (in seconds) after which basesystem tarballs will be recreated. If recreation fails, the old tarball will be used again. The default is 2592000 seconds, which is 30 days.

* "min-tgz-retry-delay" is used to specify the minimum time (in seconds) between attempts to recreate a tarball which was created more than "max-tgz-age" seconds ago. The default is 21600 seconds, which is 6h.

==== section specific configuration

The section specific settings will be reloaded each time a section
is being run.

* "log-file" is the name of a file to where the master should write its log messages. In the default configuration file it is "/dev/null", that is, log messages are not put in a file.

* "packages-url" is a URL to the Packages.bz2 file specifying what packages should be tested. This needs to be a Packages.bz2 file, other compression methods are not supported. For example, you might use 'http://ftp.debian.org/debian/dists/sid/main/binary-i386/Packages.bz2' but you really do want to replace "ftp.debian.org" with the name of your local mirror.

* "sources-url" is a URL to the Sources.bz2 file for your mirror. "sources-url" must match "packages-url", if it is not defined, piuparts-reports will not generate source centric html pages.

* "mirror" tells the slave which mirror it is to use. The slave gives this to piuparts when it runs it. Components must not be used here. "packages-url" defines which component to use. This setting is redundant and should go away.

* "piuparts-cmd" is the command the slave uses to start piuparts. It should include 'sudo' if necessary so that piuparts runs with sufficient priviledges to do its testing (and that means root priviledges).

* "distro" is the distribution the slave should tell piuparts to use for basic install/purge testing. This can be left empty if only upgrade tests should be run.

* "chroot-tgz" is the name of the file the slave should use for the tarball to keep the chroot for the basic install/purge testing. If the tarball doesn't exist, the slave creates it. This can be left empty if only upgrade tests should be run.

* "upgrade-test-distros" is the space delimited list of distributions the slave should use for testing upgrades between distributions (i.e., Debian versions). Currently, "lenny squeeze sid" is a good choice.  Leave this unset if you do not want to run upgrade tests.

* "upgrade-test-chroot-tgz" is the name of the file the slave should use for the tarball to keep the chroot for the first distribution in upgrade-test-distros. If the file does not exist, the slave creates it. This can be left empty if only basic tests should be run.

* "max-reserved" is the maximum number of packages the slave will reserve at once. It should be large enough that the host that runs master is not unduly stressed by frequent ssh logins and running master (both of which take quite a bit of CPU cycles), yet at the same time it should not be so large that one slave grabs so many packages all other slaves just sit idle. The number obviously depends on the speed of the slave. A good value seems to be enough to let the slave test packages for about an hour before reporting results and reserving more. For a contemporary AMD64 machine with a reasonably fast disk subsystem the value 50 seems to work fine. To disable a section set this to 0.

* "keep-sources-list" controls whether the slave runs piuparts with the '--keep-sources-list' option.  This option does not apply to upgrade tests.  The value should be "yes" or "no", with the default being "no".  Use this option for dists that you need a custom sources.list for, such as "stable-proposed-updates".

* "precedence" controls the order the sections are being processed by the slave. Sections with a larger precedence value will be run only if all sections with a smaller precedence value are idle, i.e. master does not have any packages that this slave could test. Sections with the same precedence value will be processed round-robin until they are all idle (or a more important section has packages to be tested). The default is 1.

* "debug" tells the slave whether to log debug level messages. The value should be "yes" or "no", with the default being "no". piuparts itself currently always produces debug output and there is no way to disable that.

Some of the configuration items are not required, but it is best
to set them all to be sure what the configuration actually is.

==== piuparts.debian.org specific configuration

In addition to some of the above settings the following
configuration settings are used by the scripts in '~piuparts?/bin/'
used to run piuparts.debian.org. They are all optional, default 
values are set in the scripts.

* "prefix" (global) sets the prefix of the piuparts installation, e.g. for finding $prefix/share/piuparts/ .

* "urlbase" (global) is the base url of the webserver serving this piuparts instance. Used to provide links to logfiles in email reports.

* "tempdir" (global) is the temporary directory to be monitored for leftover mountpoints and chroots.

* "reschedule-untestable-days" (global) sets the rescheduling delay for untestable packages (e.g. due to unsatisfied dependencies).

* "reschedule-old-days" (global, section) and the following three settings define the rescheduling scheme for passed and failed packages.

* "reschedule-old-count" (global, section)

* "reschedule-fail-days" (global, section)

* "reschedule-fail-count" (global, section)

* "auto-reschedule" (section) can be set to "no" to disable rescheduling of passed and failed packages.


=== Running piuparts in master-slave mode, piuparts-report and the setup on piuparts.debian.org

If you want to run piuparts-report (which is only+very useful if
you run piuparts in master-slave mode), you need to 'apt-get
install python-rpy r-recommended r-base-dev'. For more
information see
link:http://anonscm.debian.org/gitweb/?p=piuparts/piuparts.git;hb=piatti;a=blob;f=README_piatti.txt[http://anonscm.debian.org/gitweb/?p=piuparts/piuparts.git;hb=piatti;a=blob;f=README_piatti.txt].