[Rpm-maint] [PATCH 10/19] Add new policy requires tag to spec file format

[Steve Lawrence]

On Thu, 2010-03-04 at 13:36 +0200, Panu Matilainen wrote:
> On Tue, 2 Feb 2010, Steve Lawrence wrote:
> 
> > The PolicyRequires tag is used to specify which versions of packages are
> > required by policies installed in the module. The PolicyRequires tag has
> > the same syntax as the Requires tag.
> >
> > Assume libselinux-1.2 is installed on the system. Package foo-1.0 has a
> > policy module that 'Requires: libselinux >= 1.3'. Running the command:
> >
> > rpm -Uvh foo-1.0.rpm libselinux-1.3.rpm
> >
> > would meet all normal dependencies. However, the policy installation
> > would still fail because a policy module in foo requires a newer version
> > of libselinux than is on the system at the time of policy installation
> > (at the beginning of the transaction). The solution would be to install
> > the packages in two separate transactions:
> >
> > rpm -Uvh libselinux-1.3.rpm
> > rpm -Uvh foo-1.0.rpm
> >
> > However, this is unintuitive and not always possible.
> >
> > The new PolicyRequires directive solves this problem. The directive is
> > simply a list of dependencies, in the same format as the Requires tag,
> > that specifies what packages must already be installed at the start of
> > a transaction for policy modules to be successfully installed. This will
> > most commonly be packages like libselinux or checkpolicy.
> 
> This is another sub-case of a more generic problem and deserves a generic 
> solution.
> 
> rpmlib() dependencies are pretty much the same as this: they must be 
> satistied by the rpm running the transaction in question and can't be 
> resolved by adding more/newer packages to the set.
> 
> What this needs is essentially RPMSENSE_RUNTIME (and make RPMSENSE_RPMLIB 
> a subcase/equivalent of that). The tricky part is again initial install to 
> chroot: you can't look into the target rpmdb for providers as there will 
> be none. Does libselinux export its version through API? If so, it could 
> be used to generate an rpmlib()-style provide at runtime. Looking at hosts 
> rpmdb is not really an option as it might not even exist (installer 
> run-time image for example)
> 
>  	- Panu -
> 

Could you expand on the RPMSENSE_RUNTIME/rpmlib ideas a bit? We're not
quite sure how that would work.

Also, none of the selinux libraries export version information.