[yocto] Mapping root filesystem files back into packages

[Ulf Magnusson]

On Mon, Jan 18, 2016 at 9:15 PM, Paul Eggleton
<paul.eggleton at linux.intel.com> wrote:
> Hi Ulf,
>
> On Mon, 18 Jan 2016 10:56:41 Ulf Magnusson wrote:
>> To support an in-house packaging format, we need to partition the root
>> filesystem into a number of packages (called "internal packages" from
>> here on to avoid confusion), where each internal package corresponds
>> to a number of (e.g. IPK) packages.
>>
>> The way this is currently done is by manually maintaining a database
>> (implemented as a PACKAGE_CLASSES class) that maps files in the root
>> filesystem back to packages, along with a list of what packages should
>> go into each internal package. I suspect it is done this way so that
>> post-processing steps on the root filesystem will be included in the
>> internal packages.
>>
>> To me this feels pretty roundabout, and I suspect that there are much
>> nicer solutions (suggestions welcome!). What I'm mostly curious about
>> at the moment though is whether there's some nicer way to map files
>> from the root filesystem back to packages, without having to maintain
>> a separate database. Having the method be independent of the package
>> format (e.g., IPK) would be a bonus, though I'm not sure if it's a
>> strict requirement.
>
> So, aside from the "internal package" concept, there are two ways to do this:
>
> 1) oe-pkgdata-util find-path - this will tell you the build-time package name
> that provided the specified path within the image (expects a full path,
> wildcards allowed). It also provides some other lookup tools. Note that this
> relies on pkgdata so it'll only work for a particular recipe after that recipe
> has been packaged.
>
> 2) Use the Toaster web UI - it allows you to browse through the image and
> click through from any file back to the package that contained it.
>
> Cheers,
> Paul

Thanks for the hint!

Do you have any suggestions for the other direction as well, i.e.,
mapping packages to files, preferably in a way that's independent of
the packaging format?

I suspect this won't be a problem, but it shouldn't matter whether the
package contents are fetched from the sstate cache or not.

Cheers,
Ulf