Open Stack

On Wed, 2022-11-23 at 14:11 +0000, Stephen Finucane wrote:
> 👋
> 
> tl;dr: $subject
> 
> I reviewed a patch against openstackclient (OSC) today [1] and left a rather
> lengthy comment that I thought worthy of bringing up to a wider audience. The
> patch itself doesn't matter so much as what is was trying to achieve, namely
> modifying an existing OSC command to better match the structure of the
> equivalent legacy client command. The review provides more detail than I do here
> but the tl;dr: is that this is a big no-no and OSC will and must maintain
> consistency between OSC commands over consistency with legacy clients. As I
> noted in the review, consistency is one of the biggest advantages of OSC over
> the legacy clients: if you know the name of the resource type you wish to work
> with, you can pretty accurately guess the command and its structure. This is a
> thing that operators have consistently said they love about OSC and its one of
> the key reasons we're trying to get every command to provide full current API
> implementations in OSC (and SDK).
> 
> Now I get that the way some of these consistent commands have been implemented
> has been the cause of contention in the past. I don't imagine it remains any
> less contentious today. However, these patterns are well-understood, well-known
> patterns that have for the most part worked just fine for close to a decade now.
> The kind of patterns I'm thinking about include:
> 
>  * The command to create a new resource should always take the format
>    '<resource> create <human-readable identifer>
>  * The command to modify some property of a resource should always take the
>    format '<resource> set --property=value <name-or-identifier>'
>  * The command to list, fetch or delete resources should always take the format
>    '<resource> list', '<resource> get <name-or-identifier>', and '<resource>
>    delete <name-or-identifier>', respectively.
you have listed '<resource> get <name-or-identifier>' to fetch a resouce but in my experince
"show" is the more common action 

openstack server show <name-or-identifier>
openstack image show <name-or-identifier>
openstack volume show <name-or-identifier>

also network and port and subnet baiscaly all the resouce form the core services

get does not really seam to be used.

>  * Boolean options should always take the form of flags with an alternate
>    negative option like '--flag' and '--no-flag', rather than '--
>    flag=<true|false>'
i personally dont like this but i agree with being consitant. i strongly prefer the 
'--flag=<true|false>' approch as something that is more readble 
but its not the pattern in use in osc. i would prefer to keep things consitent then change this at this point.

>  * And a couple of other things that we tend to highlight in reviews.
> 
> We want to preserve this behavior, lest OSC lose this huge USP and devolve into
> a muddle mess of different ideas and various individuals'/teams' preferences.
> I'm more than happy to discuss and debate this stuff with anyone who's
> interested and we'll continue reviewing each patch on its merit and providing
> exceptions to these rules where they make sense, but it will remain an ongoing
> goal and it's something we'd like people to consider when working on OSC itself
> or any of its plugins.

i agree with what you said in general but there is one digerance already that we might need to reconsider.

i hate that i bring this up but one of the design guidlines of OSC was commands must not auto negociagte the latest micorverion.
that again was for consitency so that command would work the same across different clouds with different api versions.
many plugins have broken this design requirement btu the core osc client still maintains its orginal design.

to level set osc intentionally does not support microverion negocaitation, it was a desgin choice not an oversight.

since many of the plugins have ignored that and implemnted it anyway i think it would be good to provide a way to opt into the
desired behavior. i.e. provide a --latest global flag or change the default for the --os-compute-api ectr command to latest in a major
version fo osc.

we can provide a common impelmatiton in osc and the plugins can just reuse that instead of all of them that chose to suport it implemneting it them
selves.

again this goes directly against the orginial design intent fo osc to provide a stable comandline interface across
clouds with differnt versions of openstack, however since most of the peopel that cared about that have now moved on form openstack
and osc and since the comunity seam to have change its mind in providing a stable api expirence we should proably adress this divergance.

i see the fact that some plugins added micorversion negocation in direct breach of this design principal to be more problematic
form a consticy point of view then any other divergance.

> 
> I will now get off my pedestal/ivory tower 🗼
> 
> Thanks!
> Stephen
> 
> PS: I'm talking here about the command themselves, not their implementations. We
> do somethings extra in OSC that are user helpful, like allowing users to
> identify resources by their name in addition to by their UUIDs. We also
> currently do things that no so user helpful, like crashing and burning if the
> name lookups fail (I'm thinking about the various Glance-related commands that
> error out if a project name/ID is passed to a command and the user can't look up
> that project). These are things we're more than willing to fix and will happily
> accept patches for :)
> 
> [1] https://review.opendev.org/c/openstack/python-openstackclient/+/865377
> 
>