Live Systems Handbuch

Über Live Systeme

1. Über dieses Handbuch

1.1 Für die Ungeduldigen
1.2 Begriffe
1.3 Autoren
1.4 Contributing to this document
1.4.1 Applying changes
1.4.2 Translation

2. About the Live Systems Project

2.1 Motivation
2.1.1 What is wrong with current live systems
2.1.2 Why create our own live system?
2.2 Philosophy
2.2.1 Only unchanged packages from Debian "main"
2.2.2 No package configuration of the live system
2.3 Contact

Benutzer

3. Installation

3.1 Requirements
3.2 Installing live-build
3.2.1 From the Debian repository
3.2.2 From source
3.2.3 From 'snapshots'
3.3 Installing live-boot and live-config
3.3.1 From the Debian repository
3.3.2 From source
3.3.3 From 'snapshots'

4. The basics

4.1 What is a live system?
4.2 Downloading prebuilt images
4.3 Using the web live image builder
4.3.1 Web builder usage and caveats
4.4 First steps: building an ISO hybrid image
4.5 Using an ISO hybrid live image
4.5.1 Burning an ISO image to a physical medium
4.5.2 Copying an ISO hybrid image to a USB stick
4.5.3 Using the space left on a USB stick
4.5.4 Booting the live medium
4.6 Using a virtual machine for testing
4.6.1 Testing an ISO image with QEMU
4.6.2 Testing an ISO image with VirtualBox
4.7 Building and using an HDD image
4.8 Building a netboot image
4.8.1 DHCP server
4.8.2 TFTP server
4.8.3 NFS server
4.8.4 Netboot testing HowTo
4.8.5 Qemu
4.9 Webbooting
4.9.1 Getting the webboot files
4.9.2 Booting webboot images

5. Overview of tools

5.1 The live-build package
5.1.1 The lb init command
5.1.2 The lb config command
5.1.3 The lb build command
5.1.4 The lb clean command
5.2 The live-boot package
5.3 The live-config package

6. Managing a configuration

6.1 Dealing with configuration changes
6.1.1 Why use auto scripts? What do they do?
6.1.2 Use example auto scripts
6.2 Clone a configuration published via Git

7. Customization overview

7.1 Build time vs. boot time configuration
7.2 Stages of the build
7.3 Supplement lb config with files
7.4 Customization tasks

8. Customizing package installation

8.1 Package sources
8.1.1 Distribution, archive areas and mode
8.1.2 Distribution mirrors
8.1.3 Distribution mirrors used at build time
8.1.4 Distribution mirrors used at run time
8.1.5 Additional repositories
8.2 Choosing packages to install
8.2.1 Package lists
8.2.2 Using metapackages
8.2.3 Local package lists
8.2.4 Local binary package lists
8.2.5 Generated package lists
8.2.6 Using conditionals inside package lists
8.2.7 Removing packages at install time
8.2.8 Desktop and language tasks
8.2.9 Kernel flavour and version
8.2.10 Custom kernels
8.3 Installing modified or third-party packages
8.3.1 Using packages.chroot to install custom packages
8.3.2 Using an APT repository to install custom packages
8.3.3 Custom packages and APT
8.4 Configuring APT at build time
8.4.1 Choosing apt or aptitude
8.4.2 Using a proxy with APT
8.4.3 Tweaking APT to save space
8.4.4 Passing options to apt or aptitude
8.4.5 APT pinning

9. Customizing contents

9.1 Includes
9.1.1 Live/chroot local includes
9.1.2 Binary local includes
9.2 Hooks
9.2.1 Live/chroot local hooks
9.2.2 Boot-time hooks
9.2.3 Binary local hooks
9.3 Preseeding Debconf questions

10. Customizing run time behaviours

10.1 Customizing the live user
10.2 Customizing locale and language
10.3 Persistence
10.3.1 The persistence.conf file
10.3.2 Using more than one persistence store
10.4 Using persistence with encryption

11. Customizing the binary image

11.1 Bootloaders
11.2 ISO metadata

12. Customizing Debian Installer

12.1 Types of Debian Installer
12.2 Customizing Debian Installer by preseeding
12.3 Customizing Debian Installer content

Projekt

13. Contributing to the project

13.1 Making changes

14. Reporting bugs

14.1 Known issues
14.2 Rebuild from scratch
14.3 Use up-to-date packages
14.4 Collect information
14.5 Isolate the failing case if possible
14.6 Use the correct package to report the bug against
14.6.1 At build time while bootstrapping
14.6.2 At build time while installing packages
14.6.3 At boot time
14.6.4 At run time
14.7 Do the research
14.8 Where to report bugs

15. Coding Style

15.1 Compatibility
15.2 Indenting
15.3 Wrapping
15.4 Variables
15.5 Miscellaneous

16. Procedures

16.1 Major Releases
16.2 Point Releases
16.2.1 Last Point Release of a Debian Release
16.2.2 Point release announcement template

17. Git repositories

17.1 Handling multiple repositories

Beispiele

18. Examples

18.1 Using the examples
18.2 Tutorial 1: A default image
18.3 Tutorial 2: A web browser utility
18.4 Tutorial 3: A personalized image
18.4.1 First revision
18.4.2 Second revision
18.5 A VNC Kiosk Client
18.6 A base image for a 128MB USB key
18.7 A localized GNOME desktop and installer

Anhang

19. Style guide

19.1 Guidelines for authors
19.1.1 Linguistic features
19.1.2 Procedures
19.2 Guidelines for translators
19.2.1 Translation hints

Metadata

Live Systems Handbuch

Benutzer

5. Overview of tools

This chapter contains an overview of the three main tools used in building live systems: live-build, live-boot and live-config.

5.1 The live-build package

live-build is a collection of scripts to build live systems. These scripts are also referred to as "commands".

The idea behind live-build is to be a framework that uses a configuration directory to completely automate and customize all aspects of building a Live image.

Many concepts are similar to those used to build Debian packages with debhelper:

Unlike debhelper, live-build provides the tools to generate a skeleton configuration directory. This could be considered to be similar to tools such as dh-make. For more information about these tools, read on, since the remainder of this section discuses the four most important commands. Note that the preceding lb is a generic wrapper for live-build commands.

5.1.1 The lb init command

As discussed in live-build, the scripts that make up live-build read their configuration with the source command from a single directory named config/. As constructing this directory by hand would be time-consuming and error-prone, the lb init command can be used to create the initial skeleton configuration tree.

The lb init command creates the following directories inside config/: hooks/, includes/, several other includes subdirectories for each stage of the build process and package-lists/. The latter includes a list of several important live packages like live-boot, live-config and live-config-sysvinit.

5.1.2 The lb config command

Issuing lb config without any arguments completes the config/ subdirectory which it populates with some default settings in configuration files, and two skeleton trees named auto/ and local/.

$ lb config
[2014-04-25 17:14:34] lb config
P: Updating config tree for a debian/wheezy/i386 system

Using lb config without any arguments would be suitable for users who need a very basic image, or who intend to provide a more complete configuration via auto/config later (see Managing a configuration for details).

Normally, you will want to specify some options. For example, to specify which package manager to use while building the image:

$ lb config --apt aptitude

It is possible to specify many options, such as:

$ lb config --binary-images netboot --bootappend-live "boot=live components hostname=live-host username=live-user" ...

A full list of options is available in the lb_config man page.

5.1.3 The lb build command

The lb build command reads in your configuration from the config/ directory. It then runs the lower level commands needed to build your Live system.

5.1.4 The lb clean command

It is the job of the lb clean command to remove various parts of a build so subsequent builds can start from a clean state. By default, chroot, binary and source stages are cleaned, but the cache is left intact. Also, individual stages can be cleaned. For example, if you have made changes that only affect the binary stage, use lb clean --binary prior to building a new binary. If your changes invalidate the bootstrap and/or package caches, e.g. changes to --mode, --architecture, or --bootstrap, you must use lb clean --purge. See the lb_clean man page for a full list of options.

5.2 The live-boot package

live-boot is a collection of scripts providing hooks for the initramfs-tools, used to generate an initramfs capable of booting live systems, such as those created by live-build. This includes the live system ISOs, netboot tarballs, and USB stick images.

At boot time it will look for read-only media containing a /live/ directory where a root filesystem (often a compressed filesystem image like squashfs) is stored. If found, it will create a writable environment, using aufs, for Debian like systems to boot from.

More information on initial ramfs in Debian can be found in the Debian Linux Kernel Handbook at ‹http://kernel-handbook.alioth.debian.org/› in the chapter on initramfs.

5.3 The live-config package

live-config consists of the scripts that run at boot time after live-boot to configure the live system automatically. It handles such tasks as setting the hostname, locales and timezone, creating the live user, inhibiting cron jobs and performing autologin of the live user.