First, you need to install RPM devtools:

# yum install rpmdevtools

Then setup your local RPM build tree:

$ rpmdev-setuptree

This will create RPM build tree (~/rpmbuild/) in your home directory. Just a reminder – never, ever, under any circumstances, build RPMs as root user. Just a reminder. Obviously, you knew that already, right?

You also want to get and install additional header files and libraries, such as TCL/TK, expat, sqlite, etc, that are used to build some Python components:

# yum install tk-devel tcl-devel expat-devel db4-devel gdbm-devel sqlite-devel

Now we’re ready to start building an RPM. Get the RPM spec file from source build tree and copy it to your rpmbuild/SPECS directory, also copy the tarball to your build directory:

$ wget http://www.python.org/ftp/python/2.6.4/Python-2.6.4.tar.bz2
$ tar jxf Python-2.6.4.tar.bz2
$ cp Python-2.6.4/Misc/RPM/python-2.6.spec ~/rpmbuild/SPECS/
$ cp Python-2.6.4.tar.bz2 ~/rpmbuild/SOURCES/

This spec file is slightly broken and if you try building an RPM with it, it most likely is going to fail. So you need to patch it. The proposed patch has been submitted to python bug tracking system in the days of 2.6.1 release, but hasn’t yet been implemented. This patch doesn’t seem to work with 2.6.4 release and needs changing as well.

I have modified original 2.6.1 patch file slightly so that it can be used to build 2.6.4 Python RPM. You download it and apply to the original .spec:

$ cd ~/rpmbuild/SPECS/
$ wget http://www.grenadepod.com/wp-content/uploads/python-2.6.4.spec.diff
$ patch python-2.6.spec python-2.6.4.spec.diff

You should be OK to build the RPM now, but it’ll most likely fail with minor rpath-check errors, such as:

ERROR   0001: file '/usr/lib/python2.6/lib-dynload/_bsddb.so' contains a standard rpath '/usr/lib' in [/usr/lib]
ERROR   0001: file '/usr/lib/python2.6/lib-dynload/_sqlite3.so' contains a standard rpath '/usr/lib' in [/usr/lib]

Which indicates that some components are using hardcoded library paths. It’s not a big issue and can be ignored. Run build command as this:

$ QA_RPATHS=$[ 0x0001|0x0010 ] rpmbuild -ba python-2.6.spec

It should now build without any issues and the result is a set of python RPMs:

$ QA_RPATHS=$[ 0x0001|0x0010 ] rpmbuild -ba python-2.6.spec
...
Wrote: /home/pulegium/rpmbuild/SRPMS/python2.6-2.6.4-1gpod.src.rpm
Wrote: /home/pulegium/rpmbuild/RPMS/i386/python2.6-2.6.4-1gpod.i386.rpm
Wrote: /home/pulegium/rpmbuild/RPMS/i386/python2.6-devel-2.6.4-1gpod.i386.rpm
Wrote: /home/pulegium/rpmbuild/RPMS/i386/python2.6-tkinter-2.6.4-1gpod.i386.rpm
Wrote: /home/pulegium/rpmbuild/RPMS/i386/python2.6-tools-2.6.4-1gpod.i386.rpm
Wrote: /home/pulegium/rpmbuild/RPMS/i386/python2.6-debuginfo-2.6.4-1gpod.i386.rpm
...
$

This is it… You now have python RPMs that you can install on your CentOS 5.x server.

I’m planning to create my little own repository, where I’ll put this (and other) packages. For now, you can download python 2.6.4 source RPM if you want to change something in the spec file and rebuild it yourself.

Related posts:

1. Sorting out YUM repositories on CentOS 5.4
2. Use SSH to upgrade WordPress plugins automatically
3. Building and running Google Chrome OS on VirtualBox

By default, freshly installed CentOS 5.X has the following Yum repositories enabled:

addons                                             CentOS-5 - Addons
base                                               CentOS-5 - Base
extras                                             CentOS-5 - Extras
updates                                            CentOS-5 - Updates

These are all defined in /etc/yum.repos.d/CentOS-Base.repo configuration file. Repositories enabled by default provide you with the core CentOS packages and updates for them. So you must have them enabled if you want your updates to work correctly. It is also important that these repositories take precedence over other repositories that you are going to use.

I will show later how to use Yum priorities package, just note that these are going to be priority one repositories

Enable standard CentOS repositories

There are two useful repositories defined in the configuration, but not enabled:

• CentOS Plus. Packages in this repository contains upgraded versions of the software. If you enable this repository, after applying updates/upgrades your system will no longer be of the original version you have installed. Fear not though, all packages are tested by CentOS team and will no cause any issues. So unless you have really good reason to keep you installation at the same version level I’d recommend enabling this repository.
• Contrib. Packages supplied and maintained by CentOS users. These packages are not inspected by CentOS team, but they are not attempt to replace/modify core CentOS package set, so normally this repository should not cause any issues. Beware that some packages are not following mainstream CentOS very closely. I normally don’t have this enabled.

These two repositories are going to get priority two setting. If you wish to enable them, edit default /etc/yum.repos.d/CentOS-Base.repo Yum repository configuration file and remove (or rather comment out) “enabled=0” line.

Install and enable EPEL repository

I must mention, that in this article I’m mostly talking about CentOS installation that is used for server environment. Therefore I’m not really interested in repositories that provide packages such as DVD or other multimedia decoders and players.

One of the most useful repositories for your server environment is EPEL repository – Extra Packages for Enterprise Linux. This repository is maintained by Fedora project, and every effort is made to keep this repository as least  intrusive as possible, so in theory enabling and using this repository should not break or otherwise cause issues to your CentOS installation.

First of all, you need to install EPEL repository configuration files:

[root@centos54 ~]# rpm -ihv http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-3.noarch.rpm
Retrieving http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-3.noarch.rpm
warning: /var/tmp/rpm-xfer.RT5AzP: Header V3 DSA signature: NOKEY, key ID 217521f6
Preparing...                ########################################### [100%]
   1:epel-release           ########################################### [100%]
[root@centos54 ~]#

This provides you with two configuration files: base and testing. Don’t worry about testing one and leave it disabled.

Main configuration comes with three sections:

• Base packages. This is enabled by default.
• Debug packages. Disabled, and no need to enable unless you want to use debug packages.
• Source packages. Disabled. Enable only if you want to be able to install source RPMs from EPEL. Useful if you want to rebuild them to your specific needs. I’d recommend to leave it disabled and enable on yum command line only when you really need to install source RPMs.

These should be getting priority 3 setting.

Set priorities for Yum repositories

So if you enabled repositories from the previous section and installed EPEL repository configuration, here’s what you should see in you repositories list:

addons                             CentOS-5 - Addons
base                               CentOS-5 - Base
centosplus                         CentOS-5 - Plus
epel                               Extra Packages for Enterprise Linux 5 - i386
extras                             CentOS-5 - Extras
updates                            CentOS-5 - Updates

Now I need to set priorities for each repository. Install Yum priorities package:

# yum install yum-priorities

Make sure new plugin is enabled:

[root@centos54 ~]# cat /etc/yum/pluginconf.d/priorities.conf
[main]
enabled = 1
[root@centos54 ~]#

Now you can set priorities for each repository. It’s done by adding “priority=X” for each repository section in repository configuration files. Here’s what I ended up with:

[base]
...
priority=1
 
[updates]
...
priority=1
 
[addons]
...
priority=1
 
[extras]
...
priority=1
 
[centosplus]
...
priority=2
 
[contrib]
...
priority=2
 
[epel]
...
priority=3

Now you should be good to do upgrades and install packages as you see fit for your system.

Related posts:

1. Building python 2.6.4 RPM for CentOS 5.4
2. Building and running Google Chrome OS on VirtualBox
3. Use SSH to upgrade WordPress plugins automatically

• Insecure. Who knows who’s built the image and if they aren’t sending your Google login data to themselves when you login
• You’re stuck with that particular release. As I said, it’s in development, so new features and bug fixes get introduced on a daily basis

So I’ll show you how to (relatively) quickly build your very own Google Chrome OS. This instruction tells how to build Chromium OS with pre-built Chromium web browser. You will also need Sun VirtualBox.

In a nutshell:

• Install Ubuntu as a VirtualBox VM
• Download ChromeOS sources
• Build ChromeOS
• Create VMWare image
• Boot it in VirtualBox
• Enjoy

For the latest build release numbers check Chromium OS build page.

Preparation

Install Ubuntu

Do the standard installation, as you would normally do. I selected all defaults, and allocated 20GB single partition for the installation and assigned 512MB RAM.

Get OS source

Download/unpack http://build.chromium.org/buildbot/archives/chromiumos-0.4.22.8.tar.gz to /home/user/chromiumos/

NOTE! It seems that Google have removed OS tarballs and you now have to use these instructions to get the source code.

Install some additional packages required to build ChromiumOS

$ sudo apt-get install subversion pkg-config python perl g++ g++-multilib \
bison flex gperf libnss3-dev libgtk2.0-dev libnspr4-0d libasound2-dev \
libnspr4-dev msttcorefonts libgconf2-dev libcairo2-dev libdbus-1-dev
$ sudo apt-get install wdiff lighttpd php5-cgi sun-java6-fonts

OS build

Building local repository

cd ~/chromiumos/src/scripts
./make_local_repo.sh

Watch the output carefully and make sure it hasn’t failed with some errors!

Google says if the script fails, remove repo directory and call the script again. It hasn’t failed for me, so if you’ve done everything as per above you should be fine. I don’t really understand why calling the same script might make any difference…

This step is quite lengthy, so you might want to make yourself some coffee or tea. Or just take a short walk if the weather is good.

Create build environment

Another totally automated step. Just run

./make_chroot.sh

Which creates chroot’ed build environment for you. This uses all packages you downloaded in the previous step. There are adoption how to pull required packages from the remote repositories (Google and official Ubuntu), but I advise to take an easy way and download all packages first and build locally.

Get Chromium binary

make the following directory:

mkdir -p ~/chromiumos/src/build/x86/local_assets

And download chromium package from Google:

wget -O ~/chromiumos/src/build/x86/local_assets/chrome-chromeos.zip \
http://build.chromium.org/buildbot/archives/chromium-chromiumos-r32516.zip

Building OS

First you need to enter you chroot’ed build environment. Use the following command:

./enter_chroot.sh

I also recommend generating password for shared user, so that you can sudo from the terminal:

./set_shared_user_password.sh

And finally build all packages:

./build_all.sh

At this point, go and make some more tea or coffee. Which I wouldn’t recommend, though. Simply because you will have trouble getting asleep. Because sleeping is the most sane thing you might want to do at this moment. Building OS packages takes ages!…

But seriously, it’s not that bad, it took about an hour and a half on my Ubuntu VM to build it.

Make VM image and boot it in VirtualBox

Build bootable image

Once all packages have been built, you need to create OS image to boot from. Image build process creates two artefacts:
- Master boot record (mbr.image)
- Root FileSystem (rootfs.image)

./build_image.sh

Once the image files have been creates, the script will tell you where to find them. It is going to be in ~/chromiumos/src/build/images//

Here’s what you will have once the image build is done:

pulegium@ubuntu:~/chromiumos/src/build/images/999.999.33509.212332-a1$ ls -lh
total 729M
-rw-r--r--  1 pulegium 5000  512 2009-12-01 21:34 mbr.image
-rw-r--r--  1 root     root  40K 2009-12-01 21:31 package_list_installed.txt
-rw-r--r--  1 root     root  40K 2009-12-01 21:34 package_list_pruned.txt
drwxr-xr-x 22 root     root 4.0K 2009-12-01 21:29 rootfs
-rw-r--r--  1 pulegium 5000 950M 2009-12-01 21:23 rootfs.image

Tell VirtualBox to use existing image

Add new image

Image added

Selection of preinstalled application. All web based and ready to go. Make sure you have connection to the internet. Chrome OS bit dull and TBH useless without internet...

In general I think Chrome OS looks OK'ish, but this menu smells of M$ Windows...

Related posts:

1. Sorting out YUM repositories on CentOS 5.4
2. Building python 2.6.4 RPM for CentOS 5.4
3. The most unusual photocameras