diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/guix.texi | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index c0af4cb722..872caa8bf0 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -4531,7 +4531,8 @@ the ``message of the day''. Return a service that runs libc's name service cache daemon (nscd) with the given @var{config}---an @code{<nscd-configuration>} object. Optionally, @code{#:name-services} is a list of packages that provide -name service switch (NSS) modules needed by nscd. +name service switch (NSS) modules needed by nscd. @xref{Name Service +Switch}, for an example. @end deffn @defvr {Scheme Variable} %nscd-default-configuration @@ -4898,9 +4899,12 @@ next method in the list. The NSS configuration is given in the @code{name-service-switch} field of @code{operating-system} declarations (@pxref{operating-system Reference, @code{name-service-switch}}). -@c See <http://0pointer.de/lennart/projects/nss-mdns/>. +@cindex nss-mdns +@cindex .local, host name lookup As an example, the declaration below configures the NSS to use the -@code{nss-mdns} back-end for host name lookups: +@uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns} +back-end}, which supports host name lookups over multicast DNS (mDNS) +for host names ending in @code{.local}: @example (name-service-switch @@ -4926,6 +4930,34 @@ As an example, the declaration below configures the NSS to use the (name "mdns"))))) @end example +Note that, in this case, in addition to setting the +@code{name-service-switch} of the @code{operating-system} declaration, +@code{nscd-service} must be told where to find the @code{nss-mdns} +shared library (@pxref{Base Services, @code{nscd-service}}). Since the +@code{nscd} service is part of @var{%base-services}, you may want to +customize it by adding this snippet in the operating system +configuration file: + +@example +(use-modules (guix) (gnu)) + +(define %my-base-services + ;; Replace the default nscd service with one that knows + ;; about nss-mdns. + (map (lambda (mservice) + ;; "Bind" the MSERVICE monadic value to inspect it. + (mlet %store-monad ((service mservice)) + (if (member 'nscd (service-provision service)) + (nscd-service (nscd-configuration) + #:name-services (list nss-mdns)) + mservice))) + %base-services)) +@end example + +@noindent +@dots{} and then refer to @var{%my-base-services} instead of +@var{%base-services} in the @code{operating-system} declaration. + The reference for name service switch configuration is given below. It is a direct mapping of the C library's configuration file format, so please refer to the C library manual for more information (@pxref{NSS |