[PATCH] resolv/resolv.h: allow alternative resolv.conf files

[Florian Weimer]

On 08/17/2017 01:50 PM, Renzo Davoli wrote:
> In network namespaces (like vdens https://github.com/rd235/vdens) it is sometimes necessary to
> define per-namespace resolver configurations.
> 
> The simple patch here attached permits the definition of an environment variabile to define the
> path of the file to use instead of /etc/resolv.conf.

_PATH_RESCONF really has to be a string literal, and you can't use a GNU
C extension in such a way in an installed header file.

The environment variable would have to be ignored in AT_SECURE mode, so
you have to use __libc_secure_getenv or put it into unsecvars.h.

I'm still not convinced that this is the right thing to do.  Can you
share more about your use case?  I would expect that containers already
provide sufficient flexibility to adjust what is in /etc/resolv.conf.

Thanks,
Florian