[Engine-devel] engine-config utility

[Alon Bar-Lev]

----- Original Message -----
> From: "Itamar Heim" <iheim at redhat.com>
> To: "Shireesh Anjal" <sanjal at redhat.com>
> Cc: "Alon Bar-Lev" <alonbl at redhat.com>, "engine-devel" <engine-devel at ovirt.org>
> Sent: Tuesday, December 4, 2012 10:50:09 PM
> Subject: Re: [Engine-devel] engine-config utility
> 
> On 12/04/2012 04:23 PM, Shireesh Anjal wrote:
> >
> >
> > ----- Original Message -----
> >> From: "Alon Bar-Lev" <alonbl at redhat.com>
> >> To: "engine-devel" <engine-devel at ovirt.org>
> >> Sent: Tuesday, December 4, 2012 4:41:52 PM
> >> Subject: [Engine-devel] engine-config utility
> >>
> >> Hello,
> >>
> >> I had interesting discussion with Eli regarding the engine-config
> >> utility and recent commit.
> >>
> >> Is the following claim correct?
> >>
> >> """Every change of a variable by engine-config cannot break
> >> engine"""
> >>
> >> This issue came up because we used to export the CABaseDirectory
> >> parameter to engine-config. Changing it without attending to copy
> >> pki files may lead to failure. A change was already committed to
> >> remove the ability to update this parameter.
> >>
> >> Most applications I know, do allow to change variable that in
> >> certain
> >> cases may break the application. The assumption that I am usually
> >> familiar with is that the target audience of these kind of tools
> >> are
> >> system admins or integrators, which "should know what they are
> >> doing", so it is OK to expose parameters that may lead to
> >> application breakage, as the ability to customize the application
> >> is
> >> important.
> >
> > I agree with Alon. I don't think it is feasible to prevent the user
> > from every possible update of configuration that can break the
> > system.
> 
> I agree in general, and i don't think we should extend the config
> utility to test such things.
> but some basic sanity should be done (config key is legit, config
> value
> is validated for type safety/regex/enum, etc.

Right.
if Value1+Value2 = crash is not something that should be checked.
if Value1=Path while Path does not exist or contains wrong files is not something we should check.

> 
> >
> >>
> >> I am carious what other think in this regard.
> >>
> >> Regards,
> >> Alon Bar-Lev.
> >>
> >> _______________________________________________
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> >> Engine-devel at ovirt.org
> >> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >>
> > _______________________________________________
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> >
> 
> 
>