HowTo Build Images: step by step process
This page describes the steps to build your own images to boot on with an example: the Debian Squeeze 32 or 64bits system.
|
Note |
|---|---|
HowTo Build Images: using kameleon are also available for a quick setup of ComputeMode node | |
Contents |
The environment
- Create your work environment: (in your computemode server, images are usually stored into the /cm directory)
A computemode image contains:
- an "orig" directory with a basic operating system (this one will be created later)
- a "patch" directory with files to update the basic operating systems
- a "purge" file and a "rules" file, describing how to update the basic operating system (copy, link...)
- we will use the "build-image" directory to build the new system
# mkdir -p /cm/build-image # cd /cm/build-image
The orig file system
- First you have to install the Debian Live packages:
# echo "deb http://live.debian.net/ squeeze-snapshots main contrib non-free" >> /etc/apt/sources.list # wget http://live.debian.net/debian/project/keys/archive-key.asc -O - | apt-key add - # apt-get update # apt-get install live-build live-helper live-manual live-config # apt-get install schroot # lb config --distribution squeeze -a amd64 -b net --apt-options "--force-yes --yes" --debconf-frontend dialog --chroot-filesystem plain
For a 32bit mode system:
# lb config --distribution squeeze -a i386 -b net --apt-options "--force-yes --yes" --debconf-frontend dialog --chroot-filesystem plain
The "lb config" command makes the basic directories, you can, after that, create your new image. We will use the "config" directory and hooks scripts to manage the build of the new system. Some explanations about the lb config options:
- --distribution: choose your distribution between unstable, sid and squeeze
- -a: for the architecture
- -b: to choose what kind of boot we want to use
- --apt-options: some options for apt
- --debconf-frontend: to use (or not) the dialog box from apt
- --chroot-filesystem: to choose what kind of filesystem to build
- Then you have to configure your new environement:
The "config/chroot_sources" is used to configure the apt repositories for the new system. To configure additional repositories, create config/chroot_sources/your-repository.chroot
# cat <<EOF > ./config/chroot_sources/oar.chroot deb http://oar-ftp.imag.fr/oar/2.4/debian/ squeeze main EOF
For the povray's demos:
# cat <<EOF > ./config/chroot_sources/povray.chroot deb http://ftp.fr.debian.org/debian/ stable main non-free contrib EOF
The "config/chroot_local-hooks" directory is used to run commands in the chroot stage:
# cat <<EOF> ./config/chroot_local-hooks/post-build.sh #!/bin/sh echo "Launching some chrooted commands" updatedb echo "Installing Modules environment manager software" cd /tmp && wget http://downloads.sourceforge.net/project/modules/Modules/modules-3.2.8/modules-3.2.8a.tar.gz && tar zxvf modules-3.2.8a.tar.gz cd /tmp/modules-3.2.8 && ./configure && make && make install && rm -Rf /tmp/modules* EOF
The "config/chroot_local-packageslists" is used to configure what packages have to be installed into the new system:
# cat <<EOF> ./config/chroot_local-packageslists/packages.list ## This file is describing what packages we want to install iin addition of the standard flavour # For a computemode node: openssh-server less mingetty nis nfs-common acpid mlocate bind9 dnsutils bind9-doc resolvconf hwloc ntpdate # For running demos: imagemagick gfortran g++ povray povray-examples ttf-mscorefonts-installer tcl8.4 tcl8.4-dev tcllib EOF
- To build the new system just type:
# lb build
A new image is created in binary/live/filesystem.dir (you can change the filesystem type, see man lb_config). To finish the installation you just have to copy this directory into the exported /cm place.
# mkdir /cm/debian # cp -R binary/live/filesystem.dir /cm/debian/orig
- If you want to customize your image, just take a look on the man page of lb config:
# man lb_config
or the online documentation:
# http://live.debian.net/manual/en/html/live-manual.html
The patch and utils directories
Now you have a basic operating system, now you have to configure the "patch" directory to have this system working in computemode. You have an example of the "patch" directory from computemode server:
# cd /cm/debian/ # wget http://computemode.imag.fr/files/debian/squeeze/images/rootfs/patch-squeeze.tar.gz # tar zxvf ./patch-squeeze.tar.gz # chown -R root:root ./patch # rm patch-squeeze.tar.gz # wget http://computemode.imag.fr/files/debian/squeeze/images/rootfs/utils.tar.gz # tar zxvf ./utils.tar.gz |xargs chown root:root # rm utils.tar.gz
The purge and rules files
You can find an example of those files linked to the orig and patch installation done before:
# cd /cm/debian/ # wget http://computemode.imag.fr/files/debian/squeeze/images/rootfs/purge # wget http://computemode.imag.fr/files/debian/squeeze/images/rootfs/rules
Finishing the installation
The schroot command is used to install some packages and to manage automatically /proc mounts:
# cat <<EOF > /etc/schroot/chroot.d/squeeze [squeeze] description=squeeze root-groups=root root-users=root type=directory directory=/cm/debian/orig EOF
You can now customize you new system and finishing the installation:
# cp /etc/resolv.conf /cm/debian/orig/etc/resolv.conf # schroot -c squeeze -d /root # chown -R man:root /var/cache/man # apt-get install --reinstall openssh-server # apt-get install --reinstall oar-node # apt-get install --reinstall watchdog # rm -Rf /var/spool/cron/* && mkdir /var/spool/cron/atjobs && mkdir /var/spool/cron/atspool && mkdir /var/spool/cron/crontabs # echo "0" > /var/spool/cron/atjobs/.SEQ # chown -R daemon:daemon /var/spool/cron/atjobs /var/spool/cron/atspool && chown root:crontab /var/spool/cron/crontabs # passwd # ssh-keygen -t rsa # cat /root/.ssh/id_rsa.pub > /root/.ssh/authorized_keys # dpkg-reconfigure locales # dpkg-reconfigure tzdata # touch /etc/resolv.conf # exit # chroot /cm/debian/orig bash -c 'mknod -m 660 /dev/watchdog c 10 130' # chroot /cm/debian/orig bash -c 'chmod 666 /dev/null' # rm -Rf /cm/debian/orig/dev/.udev # chroot /cm/debian/orig bash -c 'if [ ! -c /dev/rtc0 ]; then mknod /dev/rtc0 c 254 0 && ln -s rtc0 /dev/rtc; fi'
To finish to configure OAR, you have to add the SSH key from your OAR server:
# cp -R /var/lib/oar/.ssh /cm/debian/patch/var/lib/oar/
To fix OAR and Bind rights:
# chown -R 105:108 /cm/debian/patch/var/lib/oar # chown 107:110 /cm/debian/orig/etc/bind/rndc.key
Just change the userid (105 and 107) and groupid (108 and 110) with your own informations from your chrooted environment (for the OAR and BIND users id and groups id in the /cm/debian environement).
- Copy needed files:
# cat /root/.ssh/id_rsa.pub >> /cm/debian/orig/root/.ssh/authorized_keys # cp /cm/debian/orig/etc/ssh/ssh_host_* /cm/debian/patch/etc/ssh/
Note: you should have the same ssh_host* key files for all your nodes.
Check if the environment="OAR_KEY=1" variable is set into the /cm/debian/patch/var/lib/oar/.ssh/authorized_keys file, if it is not the case, just run the following command:
# sed -i 's/.*/environment="OAR_KEY=1" &/g' /cm/debian/patch/var/lib/oar/.ssh/authorized_keys
- To authorize povray to write results you have to edit the povray.conf file on your image:
# vi /cm/debian/orig/etc/povray/3.6/povray.conf
and change the section:
[File I/O Security] restricted
to:
[File I/O Security] none
The tftpboot initrd and kernel
We will use the tftpboot directory generated by the previous debian-live build.
# cd /cm/build-image/tftpboot/debian-live/amd64
or :
# cd /cm/build-image/tftpboot/debian-live/i386
In this directory you will find a kernel and a initrd. You don't have to build a new kernel you can reuse the one in the tftpboot directory:
# cp vmlinuz-2.6.32-5-amd64 /var/www/bootdirectory/images/debkaufs
or:
# cp vmlinuz-2.6.32-5-686 /var/www/bootdirectory/images/debkaufs
The initrd need some cutomizations to work in computemode system:
# mkdir custom-initrd # cd custom-initrd # gzip -dc ../initrd.img-2.6.32-5-amd64 | cpio -id # wget http://computemode.imag.fr/files/debian/squeeze/images/initrd/custom-initrd-squeeze-amd64.tar.gz # tar zxvf custom-initrd-squeeze-amd64.tar.gz -C ./ # rm custom-initrd-squeeze-amd64.tar.gz # find ./ | cpio -H newc -o |gzip > /var/www/bootdirectory/images/debiaufs
or for the 32bit mode system:
# mkdir custom-initrd # cd custom-initrd # gzip -dc ../initrd.img-2.6.32-5-686 | cpio -id # wget http://computemode.imag.fr/files/debian/squeeze/images/initrd/custom-initrd-squeeze-i386.tar.gz # tar zxvf custom-initrd-squeeze-i386.tar.gz -C ./ # rm custom-initrd-squeeze-i386.tar.gz # find ./ | cpio -H newc -o |gzip > /var/www/bootdirectory/images/debiaufs
You just have to configure the computemode web interface with the new initrd debiaufs and the new kernel debkaufs.
