Juju + MAAS + Image Downloads

[Ian Booth]

On 05/09/14 09:02, David Britton wrote:
> Hi juju folks --
> 
> I'm using MAAS + Juju to do some testing behind a firewall with LXCs.  I
> want to accelerate the download of the large images that I am
> downloading from cloud-images.ubuntu.com.
> 
> I see that MAAS has cloud images.  Ideally, I'd like to instruct Juju to
> download them from there:
> 
>     https://bugs.launchpad.net/juju-core/+bug/1357045
> 
> But I'm not sure that is possible.  So, I'll leave it to someone else to
> pick up that bug if they think it's worthwhile.
> 
> I then tried to setup squid and proxy them transparently and found that
> the image-metadata-url that I give juju is only for the .json files that
> are referenced.  The images are still downloaded via https from
> cloud-images.ubuntu.com.  I'm not even sure if this is a bug.  I mean, I
> understand why you want https, but if I want to mirror it, it's a new
> level of commitment to make it https only especially in a private
> environment.
> 
> Is the only option for me to mirror cloud-images and set up an https
> endpoint (or a transparent https m-i-t-m proxy) in order to avoid
> downloading these large images over and over?
> 


I'm not an LXC (nor MAAS) expert, but I see there being 2 options:

1. Use the ubuntu-cloud template as we do now, but pass in the -T argument to
instruct the script to obtain the specified LXC images from an http endpoint
using wget. This would then replace/override the use of ubuntu-cloudimg-query
which is what reaches out now to cloud-images.canonical.com to obtain the images.

2. Use a different template script and specify it using the -t argument to
lxc-create. This script would have to replicate what's in
/usr/share/lxc/templates/lxc-ubuntu-cloud but obtain the lxc images from elsewhere.

For MAAS, if there were an endpoint which could serve the LXC tarballs, as
opposed to the root images themselves at
http://cluster-name/MAAS/static/images/ubuntu/amd64/generic/trusty/release/root-image,
then option 1 would be easiest. We could provide a new config option to specify
the correct URL to pass to -T

Thoughts?