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The app catalog has suffered this change too. We had to force v1 in our suggested download cli lines to make it work when newer clients defaulted to v2 and the previously working command line switches suddenly vanished.

As I understand, v2 had a solution to it, but that solution too was deprecated. I've heard rumor of a new suggested way of doing it, but I haven't been able to find it, so I guess its still cooking.

I'd ask the Glance team to not deprecate v1 until this issue is resolved, as it is a very common use case for Glance. I understand the desire to sluff off the old and only support a single, new api. But the new api has a big gap in it that needs to be fixed first.

Thanks,
Kevin
________________________________
From: Mikhail Fedosin [mfedosin at mirantis.com]
Sent: Tuesday, July 26, 2016 4:32 AM
To: OpenStack Development Mailing List (not for usage questions)
Subject: [openstack-dev] [Glance][Heat][Horizon] Glance v2 and custom locations

Hello!

As you may know glance v1 is going to be deprecated in Newton cycle. Almost all projects support glance v2 at this moment, Nova uses it by default. Only one thing that blocks us from complete adoption is a possibility to set custom locations to images. In v1 any user can set a location to his image, but in v2 this functionality is not allowed by default, which prevents v2 adoption in services like Horizon or Heat.

It all happens because of differences between v1 and v2 locations. In v1 it is pretty easy - user specifies an url and send a request, glance adds this url to the image and activates it.
In v2 things are more complicated: v2 supports multiple locations per image, which means that when user wants to download image file glance will choose the best one from the list of locations. It leads to some inconsistencies: user can add or delete locations from his image even if it is active.

To enable adding custom locations operator has to set True to config option 'show_multiple_locations'. After that any user will be able to add or remove his image locations, update locations metadata, and finally see locations of all images even if they were uploaded to local storage. All this things are not desired if glance v2 has public interface, because it exposes inner cloud architecture. It leads to the fact that Heat and Horizon and Nova in some cases and other services that used to set custom locations in glance v1 won't be able to adopt glance v2. Unfortunately, removing this behavior in v2 isn't easy, because it requires serious architecture changes and breaks API. Moreover, many vendors use these features in their clouds for private glance deployments and they really won't like if we break anything.

So, I want to hear opinions from Glance community and other involved people.

Best regards,
Mikhail Fedosin
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