[ubuntu-cloud] RFC: server-lucid-ec2-config: user-data configuration file

Mathias Gug mathiaz at ubuntu.com
Mon Jan 4 18:00:32 GMT 2010

Hi Eric,

On Sun, Dec 27, 2009 at 10:45:52PM -0800, Eric Hammond wrote:
> Mathias Gug wrote:
> > It seems that running apt-get update is an action that needs to be done on
> > *every* first boot.
> My other concern is the dependency on the Canonical Ubuntu archives
> hosted on EC2.  In their current architecture I do not wish to use them
> or have an outage slow down my instance startup.

This seems to be the main issue you're raising. We should make sure that Ubuntu
mirrors in ec2 are as reliable as the other archive mirrors.

> > I'm not sure I fully understand what you mean here. If existing apt mirrors are
> > removed from the sources.list (in the case of a customized instance), apt-get
> > update will not fetched them.
> It's a matter of timing.  It sounds like this order is being proposed:
> 1. ec2init scripts install Canonical mirrors on EC2.
> 2. ec2init scripts run apt-get update
> 3. user-data script is run
> 4. user-data script installs other apt mirrors
> 5. user-data script runs apt-get update
> This doesn't work for me as I'd like to avoid having (2) automatically
> run before the user-data gets a chance to set things up.

Right. And you'd like to avoid running (2) because if the mirrors are not available it
would slow down the boot process.

> It also uses a particular point in time snapshot of the Ubuntu mirrors
> (2009/12/01 in this example) which is a feature not currently offered by
> the Canonical mirrors but which helps with running only tested software
> in production EC2 environments.

I'm not sure I fully understand the point of using a snapshot of Ubuntu mirrors
if you're using a stable release. Stable releases don't change (that's why
they're *stable*). I do see a use case if you're using a development release
though. What are the other use cases you have in mind for snapshotted Ubuntu

> Proposal:
>   ec2init automatically runs apt-get update on first boot, UNLESS:
>   1. a user-data script is provided by the user (starting with #!), OR
>   2. the advanced user-data configuration format is provided by the user
>      AND that configuration specifies that apt-get update should not be
>      run.

This seems like a good proposal to me.
Mathias Gug
Ubuntu Developer  http://www.ubuntu.com

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