[Nix-dev] Re: Nixos: nssModules & nssModulesPath ?

[Ludovic Courtès]

Hi,

"Nicolas Pierron"
<nicolas.b.pierron at gmail.com> writes:

> Unfortunately, I don't have any idea what I should do with
> nssModulesPath which is an argument of upstart-jobs/default.nix.  I
> suggest to put it as an "internal" option in options.nix (or an other
> file) instead of system.nix.  I don't have any idea of the purpose of
> this variable.

`nssModulesPath' contains a search path for NSS modules.  "NSS" means
"Name Service Switch" (info "(libc) Name Service Switch"): it's a
mechanism that allows several DNS resolution methods to be specified,
via `/etc/nsswitch.conf'.

For instance, when installing Avahi and libnss-mdns, what you want is to
be able to resolve domain names ending in `.local' by using the
`libnss-mdns' module.  To that end, `nsswitch.conf' must be modified to
specify `mdns' as one of the NSS modules.  At run-time, all applications
that perform DNS lookups will transparently use it, *provided*
`libnss-mdns' is in their LD_LIBRARY_PATH.  This is where
`nssModulesPath' comes in.

Hope this helps,
Ludo'.