Introduction / Motivation

If you've been a little bit longer active as a sysadmin, you'll have faced different Linux distributions and got used to their pros and cons.

One thing though that I cannot (and do not) want to get used to, is that every distribution contains its own way of having an automated installation. May it be kickstart, preseed or aif (or any other I've not mentioned), all contain their own specific settings to do the same again and again.

Having a lot of discussions regarding this topic, there is one approach that seems to kick them all, can be automated easily and extended for other distributions (or Unices) and probably easily developed as well:

Unix = collection of files + metadata

Unices and Linux distributions are just a number of files in some particular filesystem plus some metadata like partitions (or slices), as some other people at OpenQRM have recognised this as well:

We asked ourself "what is linux ?", it is the kernel, an initrd, 
some modules and a root-filesystem. Those are all "just" files 
..... so we should treat them like files by putting and managing 
them on modern storage-servers.

But instead of doing the whole infrastructure management stuff, virtualisation (hear the cloud?) and monitoring environment, I'll just focus on the part of the installation.

Installation into/from a directory

Assume the following: Every Linux distribution can somehow be put into a directory. Either by tar'ing an existing installation or by using specific tools like debootstrap, febootstrap or archbootstrap.

This proces is pretty easy (especially if you compare it to all the options you get with the preseed/kickstart/etc., this is just one command line!) and can be used as a starting point for a generic installation.

Add some metadata

Now take this directory, and put it onto the harddisk. Installation done. Well. almost:

  • Todo before
  • Create partitions
  • Create filesystems
  • Todo after
  • Adjust /etc/fstab
  • Add correct boot loader
  • Configure network + ssh

After you've created the partitions and the filesystem (which is distribution independent!), you can copy over the files to the target diretory, in which the selected partitions are mounted.

For post processing, you need to adjust the fstab, so partitions (and swap, do not forget computers with 4 or 8 MiB main memory!) will be used at the right location. Adding a bootloader would be of great help for the boot process (almost distribution independent), though booting from the network via PXE may even get around this. Finally the network configuration (distribution specific!) must be adjusted and ssh should be installed, so the system can be configured remotely (for instance with cdist).


So the next steps are pretty straight forward: Write something that automatically

  • configures partitions
  • creates filesystems
  • mounts the filesystems
  • copies files from a know location
  • adjusts the operating system
  • umounts everything and
  • reboots

Doesn't sound like very much and so I'll probably give it a try in the next weeks, so stay tuned if you're interested in this topic.