Open Stack

I plan to register a blueprints in nova for record this. Can I?


-----邮件原件-----
发件人: Jay Pipes [mailto:jaypipes at gmail.com] 
发送时间: 2014年4月20日 21:06
收件人: openstack-dev at lists.openstack.org
主题: Re: [openstack-dev] [Nova][Neutron][Cinder][Heat]Should we support tags for os resources?

On Sun, 2014-04-20 at 08:35 +0000, Huangtianhua wrote:
> Hi all: 
> 
> Currently, the EC2 API of OpenStack only has tags support (metadata) 
> for instances. And there has already a blueprint about to add support 
> for volumes and volume snapshots using “metadata”.
> 
> There are a lot of resources such as
> image/subnet/securityGroup/networkInterface(port) are supported add 
> tags for AWS.
> 
> I think we should support tags for these resources. There may be no 
> property “metadata" for these resources, so we should to add 
> “metadata” to support the resource tags, the change related API.

Hi Tianhua,

In OpenStack, generally, the choice was made to use maps of key/value pairs instead of lists of strings (tags) to annotate objects exposed in the REST APIs. OpenStack REST APIs inconsistently call these maps of key/value pairs:

 * "properties" (Glance, Cinder Image, Volume respectively)
 * "extra_specs" (Nova InstanceType)
 * "metadata" (Nova Instance, Aggregate and InstanceGroup, Neutron)
 * "metadetails" (Nova Aggregate and InstanceGroup)
 * "system_metadata" (Nova Instance -- differs from "normal" metadata in that the key/value pairs are 'owned' by Nova, not a user...) 

Personally, I think tags are a cleaner way of annotating objects when the annotation is coming from a normal user. Tags represent by far the most common way for REST APIs to enable user-facing annotation of objects in a way that is easy to search on. I'd love to see support for tags added to any searchable/queryable object in all of the OpenStack APIs.

I'd also like to see cleanup of the aforementioned inconsistencies in how maps of key/value pairs are both implemented and named throughout the OpenStack APIs. Specifically, I'd like to see this implemented in the next major version of the Compute API:

 * Removal of the "metadetails" term
 * All key/value pairs can only be changed by users with elevated privileged system-controlled (normal users should use tags)
 * Call all these key/value pair combinations "properties" -- technically, "metadata" is "data about data", like the size of an integer. These key/value pairs are just data, not data about data.
 * Identify key/value pairs that are relied on by all of Nova to be a specific key and value combination, and make these things actual real attributes on some object model -- since that is a much greater guard for the schema of an object and enables greater performance by allowing both type safety of the underlying data and removes the need to search by both a key and a value.

Best,
-jay



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