What's the best approach to triggering a distro upgrade for an OEM build?

Question

The product I develop for work is a customised Ubuntu 8.04 LTS system with a number of back ported packages and a number of our own for the application specific stuff.

Now that 10.04 has been released it's time to start thinking about how we move our customers towards the latest LTS release. I'm currently considering the best approach to do this, preferably all triggered from a package upgrade.

I currently have a "meta" package which contains a number of prerequisites for our flavour of Ubuntu. I was thinking of issuing updated version of this in our current repo with a few upgrade scripts to be run from postinst. This would trigger the distro upgrade and then switch the custom repo bits to point to the new packages directory built against 10.04.

Is there a command line for trigger the distro upgrade? Is this the best way to proceed?

Answer 1

Your postinst could run whatever custom scripts need to happen, and finally, you could trigger the distro upgrade with:

sed -i 's/hardy/lucid' /etc/apt/sources.list
apt-get update
apt-get install dpkg apt
apt-get dist-upgrade

Your scheme could work, with plenty of testing. There may be still small things that fail and will need to be resolved by hand, but this should at least get you started.