[katello-devel] some thoughts on foreman-architectures branch

[Ivan Nečas]

On 09/06/2012 03:30 PM, Hugh Brock wrote:
> On Wed, Sep 05, 2012 at 04:30:59PM +0100, Dmitri Dolguikh wrote:
>> The logic used to access Foreman server is spread over several
>> classes: a bunch of automatically-generated proxy-type classes that
>> reside in foreman_api gem, ForemanModel (resides in
>> lib/resources/foreman_model.rb), that is a base-class for Foreman
>> resource classes that reside in app/models/foreman.
>>
>> Good things first:
>>   - app/models/foreman classes are minimal, and clearly show what
>> attributes are being used.
>>   - app/models/foreman classes allow for local validation via
>> standard ActiveModel validators.
>>   - app/models/foreman classes allow for easy customization of json
>> generation.
>>
>>
>> Things I don't like:
>>   - I can't shake the feeling that the approach represented in the
>> branch is a huge duplication of effort. We are replicating
>> ActiveResource on every step of the way, and:
>>    - ActiveResource's error handling is better/consistent (ours is
>> minimal and current approach would require us to recreate all of
>> RestClient's exceptions)
>>    - ActiveResource's error parsing is much better (we'll have to
>> duplicate AR's code to be able to parse remote errors).
>>    - Pretty much all of ForemanModel is what we'd get with
>> ActiveResource for free. Keep in mind that custom methods are simple
>> with ActiveResource.
>>   - Foreman uses rabl [1] for json-generation, we implemented a
>> custom approach. I think rabl is at least worth a look.
>>   - Apipie in it's current shape promotes code duplication. See
>> foreman_api classes, domain- and architectures-controllers in
>> katello.
>>
>>
>> I propose:
>>   - It's been close to a couple of years since we looked at
>> ActiveResource last. I'd like to see where it is now, how hard it is
>> to use with oauth and non-rails types of resource urls these days.
>>   - I'd like to evaluate rabl for use in Katello
>>   - I'd like to fix code duplication issues in Apipie, possibly
>> switch it to use ActiveResource instead of RestClient
>>
>>
>> -d
>>
>>
>> [1] https://github.com/nesquena/rabl <https://github.com/nesquena/rabl>
> Absent any knowledge of the actual code I strongly agree :).
>
> Seriously, we are using active resource pretty heavily in a lot of
> places in Conductor, I would like to see us standardize on it to the
> extent we can.
Good to hear you have real experience with that. What king of services 
do you use that for? Rails app, or something totally out of your control 
(at least partly:) ? I would like to see the actual code and ask the 
people that were working on that about their experience with that.

-- Ivan
>
> --Hugh
>
>


-- 
Ivan