定制Ubuntu安装CD

原文出处：

 

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定制Ubuntu CD的过程并不复杂，但是她有一些繁琐和过分的讲究。我对这过程的所知并不完美，因此，希望有人可以作适当修改。

安装CD有三个主要部分：

• 启动引导器：(如ISOLINUX用于amd64/i386,yaboot用于powerpc)开机时内核映象的选择与配置;
• Debian安装程序(d-i)：其实就是一个特殊的微Ubuntu系统;
• Debian软件库：放在"pool"和"dists"目录,它将占据光盘的大部分空间。

建立这个新的CD就包涵了这三部分的修改。

 用"Presseed"文件修改安装行为

当CD启动时，Linux内核就被装载且开始安装任务。安装程序的行为可以用一个"preseed"文件来修改，这些文件给Debian安装程序(d-i)回答如何配置软件包或其它相关的问题。如果您仔细看你的安装CD，您会找到这些选项(例如server,expert,oem)都有对应的preseed文件。

所以，假设您想在一群的相同配置电脑上安装breezy，并且您已经知道安装时必问问题的答案(您所在的国家和时区，您你的键盘布局，您的网络设置，您需要如何分区等等)。您可以通过"preseed"在一简单的配置文件里回答这些问题.

 改变isolinux.cfg确定您的preseed

首先，您必须告诉"d-i"找到您的preseed文件的正确位置。在标准的光盘上有个/preseed目录；您可以把您的这些文件放这里。您要修改启动引导器的配置文件/isolinux/isolinux.cfg中的相关内核参数，来告诉"d-i"找到这个文件。我的文件里有下列行：

DEFAULT /install/vmlinuz
APPEND   preseed/file=/cdrom/preseed/learnexchange.seed kbd-chooser/method=us debian-installer/locale=en_CA vga=normal initrd=/install/initrd.gz ramdisk_size=16384 root=/dev/rd/0 DEBCONF_PRIORITY=critical debconf/priority=critical rw --

"DEFAULT"是指我在boot提示符下直接按回车键装载的内核。APPEND 包涵了要传给内核的参数。preseed/file 是这儿最重要的参数；接着的那两个指出我的键盘布局用及本地为加拿大；DEBCONF_PRIORITY 用来确定我不想看到不必要的配置软件包提问。

根据你的情况小心修改这文件.

 写preseed文件

这里有很多实例；看看这个在安装盘里的--server.seed：

d-i     base-installer/kernel/linux/extra-packages-2.6  string
d-i     archive-copier/desktop-task     string ubuntu-standard
d-i     archive-copier/ship-task        string
base-config     base-config/package-selection   string ~t^ubuntu-standard$
base-config     base-config/language-pack-patterns      string language-pack-$LL
base-config     base-config/install-language-support    boolean false

(Note that the version of this file on breezy CD images was buggy: it set base-config/package-selection to "~tubuntu-standard" rather than "~t^ubuntu-standard$". Use the new version in preference; the old one will break with Ubuntu 6.04.)

首先注意格式，有 4 个部分：

• • 取得变量的程序名称
  • 答案的变量名
  • 变量类型
  • 变量值

两个要注意的地方：现在，d-i 期望有精确的类型和值；在breezy这个版本不支持用 \ 来处理多行(新的版本支持)。

我建议您从一些现有的 preseed 来修改--这儿有一个可以用的 点击。 如果您没能在这儿找到，那就试着执行这些命令：

debconf-get-selections --installer > somefile.txt
debconf-get-selections >> somefile.txt

这会输出一个您在安装时候作出的选择的列表；这文件相当地长，并且实际上不那么适合用在安装盘里。特别是，NOTE: debconf-get-selections 会在类型和只之间放 2 个空格。您得在把她放在安装盘上以前修改他们。

如果您想让 d-i 安装额外的软件包，或者一个最小的系统，您需要在preseed里修改 "base-config base-config/package-selection"。This should be set to an aptitude pattern; see the aptitude documentation for more information on these. 例如，标准安装一个SSH服务，用这一行：

base-config base-config/package-selection string ~tubuntu-standard$|~t^ubuntu-desktop$|~nopenssh-server$

To install support for additional languages, a different mechanism is available, namely to preseed the detailed locale question asked by the installer in expert mode. See the first column of `/usr/share/i18n/SUPPORTED` for the locale names you can use here. 例如, 增加孟加拉语和泰米尔语的支持，用这一行：

d-i localechooser/supported-locales multiselect ba_IN, ta_IN

 修改pool目录，增加或删除软件包

也许制定您自己的安装CD的主要原因是想改变所安装软件包；特别是您想增加一些包到CD里。这有好几个方法来做到，不需要完全地理解。最容易的事情是建立一个最小的仓库放您想要增加的包，再在制作光盘镜像文件之前合并到光盘文件体系里。这儿棘手的地方是：制作让Debian软件包管理系统知道这个仓库的相关文件；写一个更高版本的Release文件；并签上 GPG 。下面是我所做的。

• . 选定一个文件目录作为您的工作空间；在这个目录里，

mkdir -p dists/breezy/extras/binary-i386 pool/extras/ isolinux preseed

把您修改过的isolinux.cfg放在目录isolinux/，把您的preseed文件放在目录preseed里。 Put your modified isolinux.cfg in isolinux/, and your preseed file in preseed/.

• . 把您需要的所有额外的包放在目录 pool/extras/ 里。您还需要包括一个新版本的 ubuntu-keyring 包，我将马上解释一下
• . 创建并编辑文件dists/breezy/extras/binary-i386/Release，写入下面的内容:

Archive: breezy
Version: 5.10
Component: extras
Origin: Ubuntu
Label: Ubuntu
Architecture: i386

• . 把您做的修改这样合并到CD里:

a. 挂载您下载的官方ISO文件：mount /path/to/iso /some/mountpoint/ -o loop

b. 把光盘里的全部文件拷贝到某个目录(您会需要1到2G的空间)；我用rsync：sudo rsync -azvb --delete --backup-dir=/yeowe/usr/cdbuilder/old/ $MOUNT $BUILD ( 这儿的 $MOUNT 是挂载点，$BUILD 是额外的包的目录)

c. 最重要的地方. 我们将用apt-ftparchive工具来产生软件包相关和更高版本的Release文件。我们还要用GPG来签这个Release文件。安装程序会用包ubuntu-keyring 的公匙来检测签名。但是您的签名不一样。所以您得建立一个新版本的 ubuntu-keyring 包。这做起来很容易，但是要确保正确无误。下面是执行的命令：

apt-get source ubuntu-keyring
cd ubuntu-keyring--2005.01.11/keyring
gpg --import < ubuntu-archive-keyring.gpg
gpg --list-keys "Your Name"
gpg --export  FBB75451 437D05B5 YOURKEYID > ubuntu-archive-keyring.gpg
cd ..
dpkg-buildpackage -rfakeroot -m"Your Name  -k"Your Name "
cp ubuntu-keyring*deb $BUILD/pool/extras/

OK -- what we've done here is import the 2 Ubuntu keys into your main keyring, then exported them along with your own key into a replacement keyring. "YOURKEYID" should be replaced with the 8-digit hexadecimal code that gpg tells you when you do the --list-keys command above. And really, the best policy would be to do all that first, and copy a version into your $STAGE file structure so that you have it permanently available.

Note: If you do not have an existing gpg signing key, use the following code:

 gpg --gen-key

Accept all defaults, select "No expiry", and enter an appropriate passphrase.

In order to use apt-ftparchive, we will need to provide it with some defaults. Create the files "apt-ftparchive-deb.conf, "apt-ftparchive-udeb.conf", and "apt-ftparchive-extras.conf" as follows (substitude $BUILD for the absolute path to your BUILD directory, and /path/to/indices to the location of the indices files, which you can download from ):

apt-ftparchive-deb.conf:
Dir {
ArchiveDir "$BUILD";
};

TreeDefault {
Directory "pool/";
};

BinDirectory "pool/main" {
Packages "dists/breezy/main/binary-i386/Packages";
BinOverride "/path/to/indices/override.breezy.main";
ExtraOverride "path/to/indices/override.breezy.extra.main";
};

Default {
Packages {
Extensions ".deb";
Compress ". gzip";
};
};

Contents {
Compress "gzip";
};

apt-ftparchive-udeb.conf:
Dir {
ArchiveDir "$BUILD";
};

TreeDefault {
Directory "pool/";
};

BinDirectory "pool/main" {
Packages "dists/breezy/main/debian-installer/binary-i386/Packages";
BinOverride "/path/to/indices/override.breezy.main.debian-installer";
};

Default {
Packages {
Extensions ".udeb";
Compress ". gzip";
};
};

Contents {
Compress "gzip";
};

apt-ftparchive-extras.conf:
Dir {
ArchiveDir "$BUILD";
};

TreeDefault {
Directory "pool/";
};

BinDirectory "pool/extras" {
Packages "dists/breezy/extras/binary-i386/Packages";
};

Default {
Packages {
Extensions ".deb";
Compress ". gzip";
};
};

Contents {
Compress "gzip";
};

• . 现在就用apt-ftparchive来创建Packages和Release文件：

cd $BUILD
sudo apt-ftparchive -c $APTCONF generate /path/to/apt-ftparchive-deb.conf
sudo apt-ftparchive -c $APTCONF generate /path/to/apt-ftparchive-udeb.conf
sudo apt-ftparchive -c $APTCONF generate /path/to/apt-ftparchive-extras.conf

$APTCONF is a file somewhere that looks about like this:

APT::FTPArchive::Release::Origin "Ubuntu";
APT::FTPArchive::Release::Label "Ubuntu";
APT::FTPArchive::Release::Suite "breezy";
APT::FTPArchive::Release::Version "5.10";
APT::FTPArchive::Release::Codename "breezy";
APT::FTPArchive::Release::Architectures "i386";
APT::FTPArchive::Release::Components "main restricted extras";
APT::FTPArchive::Release::Description "Ubuntu Breezy";

a. 给Release文件签gpg:

sudo gpg --default-key "MY GPG KEY ID" --output $BUILD/dists/breezy/Release.gpg -ba $BUILD/dists/breezy/Release

• . Regenerate the md5 checksums:

cd $BUILD find . -type f -print0 | xargs -0 md5sum > md5sum.txt

• . 现在可以来生成光盘镜像文件：

sudo mkisofs -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -J -hide-rr-moved -o $IMAGE -R $BUILD/

‘$IMAGE’表示您的光盘镜像文件.

• . 最後，可以用cdrecord或其它刻录工具来刻录您的CD了：

sudo nice -18 cdrecord dev=ATA:1,1,0 speed=12 --blank=fast -v -gracetime=2 -tao $IMAGE

that will burn the image on the second cd drive; if your cd-burner is the first or only cd-drive, change dev argument to ATA``:1,0,0. I strongly recommend using rewritable media -- I've burned a LOT of coasters on this project.

好了，搞定！ 如果谁感兴趣，我写了一个小脚本(很简单)来自动完成这个步骤。我想我正好可以放在这儿

ORIG="/var/www/jigdo/$1-breezy-install-i386.iso"
STAGE="/home/matt/LearningExchangeCD/$1/"
MOUNT=/mnt/iso/
BUILD="/yeowe/usr/cdbuilder/$1"
IMAGE="/yeowe/usr/cdbuilder/$1-learningexchange.iso"
APTCONF=/home/matt/LearningExchangeCD/apt.conf 


sudo umount $MOUNT
sudo mount $ORIG $MOUNT -o loop
sudo rsync -azvb --delete  $MOUNT $BUILD
sudo rm -r $BUILD/pool/u/ubuntu-keyring/
sudo rsync -avzb --exclude='*~' --exclude='INSTRUCTIONS.txt' --backup-dir=/yeowe/usr/cdbuilder/old/ --exclude='example-preseed.txt' $STAGE $BUILD


sudo rm $BUILD/dists/breezy/Release*
for component in main extras; do
sudo apt-ftparchive packages "$BUILD/pool/$component/" > "$BUILD/dists/breezy/$component/binary-i386/Packages"
gzip -c "$BUILD/dists/breezy/$component/binary-i386/Packages" | \
sudo tee "$BUILD/dists/breezy/$component/binary-i386/Packages.gz" > /dev/null
done
sudo apt-ftparchive -c $APTCONF release $BUILD/dists/breezy > $BUILD/dists/breezy/Release
sudo gpg --output $BUILD/dists/breezy/Release.gpg -ba $BUILD/dists/breezy/Release

sudo chown -R root:root $BUILD/isolinux  $BUILD/preseed 
sudo mkisofs -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -J -hide-rr-moved -o $IMAGE -R $BUILD/

sudo nice -18 cdrecord dev=ATA:1,1,0 speed=12 --blank=fast -v -gracetime=2 -tao $IMAGE