[katello-devel] Modelling of environments, products, etc in Katello (related to renaming of environments)

Dmitri Dolguikh dmitri at redhat.com
Thu Aug 9 13:08:50 UTC 2012


On 09/08/12 01:49 PM, Justin Sherrill wrote:
> On 08/09/2012 08:39 AM, Dmitri Dolguikh wrote:
>> On 09/08/12 01:20 PM, James Bowes wrote:
>>> On Thu, Aug 09, 2012 at 12:34:57PM +0100, Dmitri Dolguikh wrote:
>>>> Please see https://bugzilla.redhat.com/show_bug.cgi?id=795928 for
>>>> description of an issue with environment renaming.
>>>>
>>>> The immediate problems around environments: using of environment
>>>> names and environment ids for identification of environments
>>>> interchangeably. Using db ids for environment identification when
>>>> not using environment names.
>>>>
>>>> To resolve these:
>>>>   - introduce environment uuids
>>>>   - update katello/katello cli to use uuids for environment 
>>>> identification
>>>>   - update repository naming to use environment uuids
>>>>   - update candlepin (this will include updates to schema, and
>>>> resource controller)
>>>>
>>> -1 to UUIDs, for the same reason as has been discussed wrt pulp
>>> repo labels. a url like:
>>>
>>> https://my-cdn.local/content/dev/rhel-server/i386/
>>>
>>> is way more useful than:
>>>
>>> https://my-cdn.local/content/abc123213-23423423-aaa123/rhel-server/i386/ 
>>>
>>>
>>> not to mention, far more handsome!
>>>
>>> I'd rather see either immutable labels, or supporting renaming labels,
>>> too.
>> The issue boils down to renaming of environments. If we are to use 
>> environment names for environment identification, we have to provide 
>> resolution for urls that are no longer valid (via 301). Doable, but 
>> additional work.
>>
>> The idea of labels is interesting, but I don't think it would work 
>> out in the long-term: it would become stale after a rename or two
>>
> I would agree with you, except for the fact that in Satellite many 
> different objects used the idea of a mutable name and an immutable 
> label (especially for repos).   I don't know that I once heard a 
> complaint from a customer that they couldn't rename a label or that it 
> was stale.
>
I just don't think it's possible to communicate the intent using a short 
(for the benefit of usability) label, so that the label would stay 
constant while environment name kept changing.

Perhaps renaming of environments is overrated?
-d


> Do you have any thoughts cliff?
>
> -Justin
>
>
>> With uuid's we won't need to support url redirection, they won't go 
>> stale. For user-friendliness we should provide querying by name with 
>> environment resource, smt. like:
>>
>> GET 
>> http://localhost/katello/api/organizations/ACME_Corporation/environments?name=super-duper
>>
>> Less convenient, but easier to implement and maintain (from both user 
>> and developer perspective).
>>
>> -d
>>
>>>
>>> To clarify, UUIDs are fine imo as an internal canonical id for envs
>>> within katello as a whole, but once the env is exposed on the cli or in
>>> a url, label should be used.
>>>
>>>> The larger problem: Katello and Candlepin modelling of
>>>> products/product content/environments lost coherency.
>>>>
>>>> Candlepin's view of the above trifecta (use of a monospaced font is
>>>> encouraged for the content below):
>>>> +-------------+          +--------------------+
>>>> | Environment | 1 <--- * | EnvironmentContent |
>>>> +-------------+          +--------------------+
>>>>                                  ^
>>>>                                  | *
>>>>                                  | 1
>>>> +---------+          +----------------+
>>>>      | Product | 1 ---> * | ProductContent |
>>>>      +---------+          +----------------+
>>>>
>>>>
>>>> same thing in Katello (with added pulp repositories):
>>>>
>>>>     +-------------+
>>>>     | Pulp::Repos |<-----------------------+
>>>>     +-------------+                        |
>>>>         ^                                  |
>>>>         | uses                             |
>>>>      +----------------------------------+  | +-------------+
>>>>      | Candlepin::Product               |  |  | Environment |
>>>>      | (uses Candlepin::ProductContent) |  | +-------------+
>>>>      +----------------------------------+  |          ^
>>>>         |       ^                          |          | 1
>>>>         |uses   | uses                     |          |
>>>>         |       |                          |          | *
>>>> +---------+                      +--------------------+
>>>>        | Product | 1 ---------------> * | EnvironmentProduct |
>>>>        +---------+ +--------------------+
>>>>                                            |          |1
>>>>                                            |          |*
>>>>                                            |          V
>>>>                                            | uses +------------+
>>>>                                            +------| Repository |
>>>> +------------+
>>>>
>>>>
>>>> I propose:
>>>>   - Rename EnvironmentProduct to ProductContent
>>>>     - make it use Candlepin::ProductContent
>>>>     - remove use of Pulp::Repos from Product
>>>>     - delegate responsibility of generation of environment uuids to
>>>> Candlepin (should cp folks agree on this)
>>>>
>>>> resulting in:
>>>>
>>>>                          +-------------+
>>>>                          | Environment |
>>>>                          +-------------+
>>>>                                 ^
>>>>                                 | 1
>>>>                                 | *
>>>>    +---------+          +----------------+
>>>>    | Product | 1 ---> * | ProductContent |
>>>>    +---------+          +----------------+
>>>>                             |1  | uses
>>>>                             |   | +---------------------------+
>>>>                             |1  +->  | Candlepin::ProductContent |
>>>>                             V +---------------------------+
>>>>      +-------------+ uses +------------+
>>>>      | Pulp::Repos |<-----| Repository |
>>>>      +-------------+      +------------+
>>>>
>>>> I don't think many-1 relation is required on
>>>> Repository-ProductContent, it's 1-1?
>>>>
>>>>
>>>> Thoughts, concerns, opinions?
>>>> -d
>>>>
>>>>
>>>>
>>>>
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>>>> https://www.redhat.com/mailman/listinfo/katello-devel
>>>
>>> -James
>>
>>
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