Debian Appliance Builder

Introduction

Creating high quality appliances is a difficult task and requires deep knowledge of the underlying operating system. So we created the 'Debian Appliance Builder' to simplify that task. 'dab' is a script to automate the creation of OpenVZ appliances. It is basically a rewrite of debootstrap in perl, but uses OpenVZ instead of chroot and generates OpenVZ templates. Another difference is that it supports multi-stage building of templates. That way you can execute arbitrary scripts between package installation steps to accomplish what you want.

Furthermore, some common tasks are fully automated - like setting up a database server (mysql or postgres). To accomplish minimal template creation time, packages are cached to a local directory, so you do not need a local Debian mirror (although this would speed up the first run). All generated templates includes an appliance description file. Those can be used to build appliance repositories.

'dab' is licensed under GPLv2 (Open source).

Main features

• Fully automated build process with standard 'make' scripts
• Local package cache
• Multi-stage build process
• Creates and includes appliance description files
• Simplifies various tasks like database installation
• Appliances can be certified and integrated into the Proxmox VE download directory
• Supports Debian 6 (Squeeze) based appliances
• Generates 32 or 64 bit appliances
• Automatic dependency resolution

Target audience

'dab' is an easy way for software vendors and open source project to package their product into a "ready-to-run" appliance. Appliances can be published into the Proxmox VE appliance download directory to reach the target customer. See Download templates (Video).

In order to work with 'dab', basic Linux knowledge is needed.

Installation

The script needs to be run as root, so it is not recommended to start it on a production machine with running containers.

System requirements

Prepare your operating system - you can install 'dab' on the following operating systems:

• Proxmox VE (fastest)
• Proxmox VE inside Proxmox VE (KVM) - (most comfortable)
• Proxmox VE inside VMWare/XEN 64bit virtual machine
• Debian 64/Ubuntu 64 with OpenVZ Kernel (not tested)

'dab' installation

Log into Proxmox VE, and install 'dab' using apt:

apt-get install dab

Or download and install it manually:

wget http://download.proxmox.com/debian/dists/lenny/pve/binary-amd64/dab_1.1-14_all.deb
dpkg -i dab_1.1-14_all.deb

'dab' sample templates

A set of examples is also available. Simply download them:

Check for current examples at ftp://download.proxmox.com/sources/

wget http://download.proxmox.com/sources/http://download.proxmox.com/sources/dab-pve-appliances_2011-05-10.tar.gz

Unpack with tar:

tar -zxvf dab-pve-appliances_2011-05-10.tar.gz

'dab' manual pages

dab(1)                User Contributed Perl Documentation               dab(1)



NAME
       dab - Debian OpenVZ Appliance Builder

SYNOPSIS
       dab command [OPTIONS]
       dab init
           Downloads the package descriptions form the repository. Also
           truncates the "logfile".

       dab bootstrap
           Bootstrap a debian system and allocate a temporary container (we
           use IDs 90000 and above).

           --exim
               Use exim as MTA (we use postfix by default)

           --minimal
               Do not install standard packages.

       dab veid
           Print used container ID.

       dab basedir
           Print container private directory.

       dab packagefile
           Print the appliance file name.

       dab install pkg ...
           Install one or more packages. pkg can also refer to a file named
           "xyz.pkglist" which contains a list of packages. All dependencies
           are automatically installed.

       dab unpack pkg ...
           Unpack one or more packages. pkg can also refer to a file named
           "xyz.pkglist" which contains a list of packages. All dependencies
           are automatically unpacked.

       dab exec CMD ARGS
           Executes command CMD inside the container.

       dab enter
           Calls "vzctl enter CTID" - this is for debugging only.

       dab task mysql
           Install a mysql database server. During appliance generation we use
           "admin" as mysql root password (also stored in /root/.my.cnf).

           --password=XXX
               Specify the mysql root password. The special value "random" can
               be use to generate a random root password when the appliance is
               started first time (stored in /root/.my.cnf)

           --start
               Start the mysql server (if you want to execute sql commands
               during appliance generation).

       dab task postgres
           Install a postgres database server.

           --version=XXX
               Select Postgres version. Posible values are 7.4, 8.1 and 8.3
               (depends on the selected suite).

           --start
               Start the postgres server (if you want to execute sql commands
               during appliance generation).

       dab task php
           Install php5.

           --memlimit=i
               Set the php memory_limit.

       dab finalize
           Cleanup everything inside the container and generate the final
           appliance package.

           --keepmycnf
               Do not delete file "/root/.my.cfg" (mysql).

       dab list
           List installed packages.

           --verbose
               Also print package versions.

       dab clean
           Remove all temporary file and destroy the used OpenVZ container.

       dab dist-clean
           Like clean, but also removes the package cache (except when you
           specified your own cache directory in the config file)

DESCRIPTION
       dab is a script to automate the creation of OpenVZ appliances. It is
       basically a rewrite of debootstrap in perl, but uses OpenVZ instead of
       chroot and generates OpenVZ templates. Another difference is that it
       supports multi-stage building of templates. That way you can execute
       arbitrary scripts between to accomplish what you want.

       Furthermore some common tasks are fully automated, like setting up a
       database server (mysql or postgres).

       To accomplish minimal template creation time, packages are cached to a
       local directory, so you do not need a local debian mirror (although
       this would speed up the first run).

       See http://pve.proxmox.com/wiki/Debian_Appliance_Builder for examples.

       This script need to be run as root, so it is not recommended to start
       it on a production machine with running container. Proxmox VE
       (http://pve.proxmox.com) is the preferred environment, because it is
       able to log the console output when a container starts. You wont be
       able to detect errors during container startup when running on standard
       OpenVZ. So many people run Proxmox VE inside a KVM or VMWare 64bit
       virtual machine to build appliances.

       All generated templates includes an appliance description file. Those
       can be used to build appliance repositories.

CONFIGURATION
       Configuration is read from the file "dab.conf" inside the current
       working directory. The files contains key value pairs, separated by
       colon.

       Suite: etch|lenny|squeeze|hardy|intrepid|jaunty
         The Debian or Ubuntu suite.

       Source: URL [components]
         Defines a source location. By default we use the following for
         debian:

          Source: http://ftp.debian.org/debian SUITE main contrib
          Source: http://security.debian.org SUITE/updates main contrib

         Note: SUITE is a variable and will be substituted.

         There are also reasonable defaults for Ubuntu. If you do not specify
         any source the defaults are used.

       Depends: dependencies
         Debian like package dependencies. This can be used to make sure that
         speific package versions are available.

       CacheDir: path
         Allows you to specify the directory where downloaded packages are
         cached.

       Mirror: SRCURL => DSTURL
         Define a mirror location. for example:

          Mirror: http://ftp.debian.org/debian => ftp://mirror/debian

       All other settings in this files are also included into the appliance
       description file.

       Name: name
         The name of the appliance.

         Appliance names must consist only of lower case letters (a-z), digits
         (0-9), plus (+) and minus (-) signs, and periods (.). They must be at
         least two characters long and must start with an alphanumeric
         character.

       Architecture: i386|amd64
         Target architecture.

       Version: upstream_version[-build_revision]
         The version number of an appliance.

         =item: Section: section

         This field specifies an application area into which the appliance has
         been classified. Currently we use the following section names:
         system, admin, www

       Maintainer: name <email>
         The appliance maintainer’s name and email address. The name should
         come first, then the email address inside angle brackets <> (in
         RFC822 format).

       Infopage: URL
         Link to web page containing more informations about this appliance.

       Description: single line synopsis
          extended description over several lines (indended by space) may follow.

Appliance description file
       All generated templates includes an appliance description file called

        /etc/appliance.info

       this is the first file inside the tar archive. That way it can be
       easily exctracted without scanning the whole archive. The file itself
       contains informations like a debian "control" file. It can be used to
       build appliance repositories.

       Most fields are directly copied from the configuration file "dab.conf".

       Additionally there are some auto-generated files:

       Installed-Size: bytes
           It gives the total amount of disk space required to install the
           named appliance. The disk space is represented in megabytes as a
           simple decimal number.

       Type: type
           This is always "openvz".

       OS: [debian-4.0|debian-5.0|ubuntu-8.0]
           Operation system.

       Appliance repositories usually add additional fields:

       md5sum: md5sum
           MD5 checksum

FILES
       The following files are created inside your working directory:

        dab.conf          appliance configuration file

        logfile           contains installation logs

        .veid             stores the used container ID

        cache/*           default package cache directory

        info/*            package information cache

AUTHOR
       Dietmar Maurer <dietmar@proxmox.com>

       Many thanks to Proxmox Server Solutions (www.proxmox.com) for
       sponsoring this work.

COPYRIGHT AND DISCLAIMER
       Copyright (C) 2007-2009 Proxmox Server Solutions GmbH

       Copyright: dab is under GNU GPL, the GNU General Public License.

       This program is free software; you can redistribute it and/or modify it
       under the terms of the GNU General Public License as published by the
       Free Software Foundation; version 2 dated June, 1991.

       This program is distributed in the hope that it will be useful, but
       WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       General Public License for more details.

       You should have received a copy of the GNU General Public License along
       with this program; if not, write to the Free Software Foundation, Inc.,
       51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

POD ERRORS
       Hey! The above document had some coding errors, which are explained
       below:

       Around line 382:
           =back without =over



1.1                               2011-05-09                            dab(1)

Build Virtual Appliances

We published several examples to show how to work with 'dab'. To start, just build a first OS template based on our examples. If you understand the basics, you can start customizing your own appliance (based on a standard OS template).

Basic recommendations:

• Choose the best suitable base OS (squeeze)
• Choose the right architecture (i383 or amd64)
• Always try to use deb packages for applications (instead of tar.gz files)
• Pre-configure applications as much as possible (PHP, Apache, MySql, Postgresql, etc.) - based on the recommendations of the software
• Use unique keys and passwords (auto generate them during first start-up)
• Define the update procedure for users running the appliance in production: if you use Debian packages, update is easy (apt-get update)
• Contact the Proxmox support team for help Proxmox Support Forum
• And finally: Get certified! See Certification Overview

Debian 6 Standard (Squeeze, i386)

This example shows the basic steps when creating appliances with 'dab'. First step is to create a temporary working directory and cd into that directory (or just cd into the previously un-tared examples):

mkdir debian-6.0-standard
cd debian-6.0-standard

Now you need to create/edit the configuration file called 'dab.conf':

Suite: lenny
Architecture: i386
Name: debian-6.0-standard
Version: 6.0-1
Section: system
Maintainer: Proxmox Support Team <support@proxmox.com>
Infopage: http://pve.proxmox.com/wiki/Debian_6.0_Standard
Description: Debian 6.0 (standard)
 A small Debian Lenny system including all standard packages.

Next step: Download the available package lists:

dab init

Start the creation process with:

dab bootstrap

Finally build the final appliance package with:

dab finalize

Thats all. Simply upload the final template to your Proxmox VE server (/var/lib/vz/template/cache/) and test what you created. Sure, always check if everything went well before releasing a template. For this purpose all output is logged to a file called 'logfile'.

When finished you may want to cleanup your working directory with:

dab clean

or use 'dist-clean' if you also want to erase the package cache directory:

dab dist-clean

You can automate above steps using make. Simply create a file called 'Makefile' (here is an example):

BASEDIR:=$(shell dab basedir)

all: info/init_ok
        dab bootstrap
        dab finalize

info/init_ok: dab.conf
        dab init
        touch $@

.PHONY: clean
clean:
        dab clean
        rm -f *~

.PHONY: dist-clean
dist-clean:
        dab dist-clean
        rm -f *~

To start template creation you can now simply type:

make

and

make clean

to cleanup the directory.

The Build your first DAB Appliance Template page shows how to practically setup DAB and get along building templates.

Other OS sample Appliances

These example OS templates are included in the dab-pve-appliances

• Debian 6.0 Standard (i386)
• Debian 6 Standard (amd64)

Sample Application Appliances

These example application templates are included in the dab-pve-appliances

• Drupal (Debian Squeeze, i386)
• MediaWiki (Debian Squeeze, i386)
• Joomla! (Debian Squeeze, i386)
• Wordpress (Debian Squeeze, i386)
• SugarCRM (Debian Squeeze, i386)
• RT Request Tracker (Debian Squeeze, i386)

Howto certify a Virtual Appliance

See Certification Overview

Get support

Get support including commercial support offering concerning 'dab'.