From: "Alon Bar-Lev" <alonbl(a)redhat.com&gt; To: "engine-devel" <engine-devel(a)ovirt.org&gt; 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 am carious what other think in this regard. Regards, Alon Bar-Lev. _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel

From: "Itamar Heim" <iheim(a)redhat.com&gt; To: "Shireesh Anjal" <sanjal(a)redhat.com&gt; Cc: "Alon Bar-Lev" <alonbl(a)redhat.com&gt;, "engine-devel" <engine-devel(a)ovirt.org&gt; 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(a)redhat.com&gt; >> To: "engine-devel" <engine-devel(a)ovirt.org&gt; >> 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.

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