[Freeipa-devel] New/Updated FreeIPA design pages

[Simo Sorce]

On Tue, 16 Dec 2014 10:40:20 -0500
Simo Sorce <simo at redhat.com> wrote:

> On Tue, 16 Dec 2014 15:57:34 +0100
> Ludwig Krispenz <lkrispen at redhat.com> wrote:
> 
> > 
> > On 12/16/2014 03:22 PM, Simo Sorce wrote:
> > > On Tue, 16 Dec 2014 11:33:41 +0100
> > > Ludwig Krispenz <lkrispen at redhat.com> wrote:
> > >
> > >> Hi Simo,
> > >>
> > >> one thing is not quite clear to me: do you want a domain level
> > >> per feature or a global domain level or both ?
> > > The Domain Level is global.
> > > I described a "Feature Version" that is published by feature.
> > > The Feature Versions just state what is available they do not
> > > determine what is the current overall Domain Level.
> > Ok, just to confirm my understanding.
> > 
> > - we have one domain level.
> 
> Yes.
> 
> > - each (new) plugin or compoment has to define its minimal domain
> > level and execute only features covered by this level
> 
> Each plugin may have different behavior based on the domain level it
> is enabled, however the highest level is open-ended. IE a plugin must
> not stop working if it see a higher level than was known when it was
> built.
> 
> SO a plugin may have an if/else like this:
> 
> if (level < MIN_DOM_LEVEL) {
>    return;
> } else if (level < XYZ_DOM_LEVEL) {
>    /* do something */
> } else {
>    /* do something else */
> }
> 
> The last branch is always there unless we are going to stop using a
> plugin and intentionally want it to stop working once the domain level
> is raised past the XYZ_DOM_LEVEL (whatever that will be).
> 
> > - in addition, these plugins have to expose their (plugin)  version
> > on each server, allowing checks for setting the domain level
> 
> Yes,
> we can refine this part though, for example each plugin could publish
> the minimum domain level is supports instead of a version number if
> that is useful or easier to manage. But this is not sufficient to do
> checks, we still need to know, in some cases, also what is the
> maximum level known for some plugins (but not for others), so we'll
> still need a detailed list of things to check.
> 
> If this is too complex however, maybe we can simply publish a
> "supported domain level" number per server, and deal internally within
> a server on how to publish it.

A "supported domain levels" range really, so we can say IPA v8.0 support
level 2-3-4 but not 0 or 1 or 5 (which is supported only by v9.0

Actually, I think I will go and change the proposal this way, it will
make it much easier to deal with for checks.

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York