Default-Image-Id

[Ian Booth]

Hi

On 22/04/13 13:41, anirup dutta wrote:
> Hey Ian,
> 
> Thanks for the information. I am kind of surprised because, the earlier
> versions of Juju allowed specifying a user defined default image by putting
> it up in the environmental configuration (
> https://juju.ubuntu.com/docs/provider-configuration-ec2.html) so I didn't
> expect the feature to be removed. Good to hear that it is making a
> comeback.
> 

The documentation you refer to is for the old Python version of juju, which is
being replaced in 13.04 with a version written in Go. Both versions will be able
to co-exist but the Go version is the way forward. In the new version, the use
of default-image-id is currently deprecated as a means to explicitly choose a
specific image to run (that's *my* understanding at least).

So it's not really making a comeback as such. juju will first attempt to find an
instance to run based on the image metadata in
http://cloud-images.ubuntu.com. Only if an image cannot be found there will
default-instance-id be considered. Given that for EC2 the image metadata is all
available from the above URL, the default-image-id will never normally be
considered. And note that as of now, the code to provide this fallback behaviour
for EC2 still has not landed - it's currently being discussed.

> I have a question, is there a workaround. I don't want to start with a
> vanilla instance and I would rather prefer to use my own customized ami
> because it would save me a lot of time in setting up my deployments. In the
> kind of experiments, I am running using Juju, I deploy them for few hours
> and then tore them down.
>

As of now, in the currently released 1.9.14 version of Go juju, I do not know of
a workaround for EC2.

> Or should I fall back to an older version of Juju. I think 0.6(honolulu)
> release or 0.5.3 should support it.
>

The older Python version will support it, but this are no longer under active
development and will not be around forever.

Disclaimer: What I say above is my own understanding of the issue. You clearly
have a need for some behaviour which is changing in the new version of juju.
Hopefully others can shed some more light on the reasoning etc and help you with
a way forward.