`snap` should provide functionality to find non-installed snap which contain known file (analog of `apt-file search`)

this apt behaviour might conceptually not be feasible for snaps, do not forget that snaps usually ship their dependencies included ...

something like a "snap find-file npm" could give you 1000s of useless results (simply every node based snap in the store), you would simply end up with massive duplication.

while an "apt-file search libpng1.2" will only return the few apt packages that actually ship libpng (which will then be used via the binary package dependency system), in the snap world it would simply return every graphical app including this lib in the snap (due to the fact that snaps explicitly forbid dependencies you will likely never have something like a libpng-snap). dependency resolution of snaps happens via parts at build-time in snapcraft, not at run-time via binary package dependencies like in the apt/dpkg world.

On Sat, Feb 10, 2018 at 05:34:48PM -0000, Oliver Grawert wrote:
> something like a "snap find-file npm" could give you 1000s of useless
> results (simply every node based snap in the store), you would simply
> end up with massive duplication.

Perhaps one is looking for snaps that have a vulnerable library or
specific data contents. "useless" is highly subjective.

Thanks

yeah, well, i simply think the sheer amount of returned data will make it useless to standard endusers (compared to apt-file which will return a handfull of packages due to the different design of the packaging format)

also ... while in deb packages you will have a guarantee what the "libz.so.1.2.3.4" binary contains, how will you know that the 8474583754 returned "libz.so.1.2.3.4" form a

"snap-file find libz.so.1.2.3.4"

is actually returning info about the same binary ?

some snaps might use libz.so.1.2.3.4 from a binary deb from the archive, others might build upstream without any patches and others again might build upstream with patches, all binaries your file search would be named libz.so.1.2.3.4 but you will not actually know if their binary content is identical ... how would "snap-file search..." know *which* binary libz.so.1.2.3.4 you actually want to find ...

I can see the use case here, but I tend to agree with @ogra that it is not as useful as for debs and the sheer quantity of the output will make it difficult to actually do anything useful with the output. Setting as wishlist for now, if there are additional use cases for this feature, please feel free to comment on this bug or create a post at forum.snapcraft.io where we can discuss this with snapd architects.

Also note that this feature would require work from the snap-store team as well.