From 33b7cb7a595aa33051648039d417338110e5a45e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Sat, 30 Nov 2019 18:05:07 +0100 Subject: services: Add 'provenance-service-type'. * gnu/services.scm (object->pretty-string) (channel->code, channel->sexp, provenance-file) (provenance-entry): New procedures. (provenance-service-type): New variable. * gnu/system.scm (operating-system-with-provenance): New procedure. * doc/guix.texi (Service Reference): Document 'provenance-service-type'. --- doc/guix.texi | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'doc/guix.texi') diff --git a/doc/guix.texi b/doc/guix.texi index 7d50f31d20..33ee81b150 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -27043,6 +27043,50 @@ programs under @file{/run/current-system/profile}. Other services can extend it by passing it lists of packages to add to the system profile. @end defvr +@cindex provenance tracking, of the operating system +@defvr {Scheme Variable} provenance-service-type +This is the type of the service that records @dfn{provenance meta-data} +in the system itself. It creates several files under +@file{/run/current-system}: + +@table @file +@item channels.scm +This is a ``channel file'' that can be passed to @command{guix pull -C} +or @command{guix time-machine -C}, and which describes the channels used +to build the system, if that information was available +(@pxref{Channels}). + +@item configuration.scm +This is the file that was passed as the value for this +@code{provenance-service-type} service. By default, @command{guix +system reconfigure} automatically passes the OS configuration file it +received on the command line. + +@item provenance +This contains the same information as the two other files but in a +format that is more readily processable. +@end table + +In general, these two pieces of information (channels and configuration +file) are enough to reproduce the operating system ``from source''. + +@quotation Caveats +This information is necessary to rebuild your operating system, but it +is not always sufficient. In particular, @file{configuration.scm} +itself is insufficient if it is not self-contained---if it refers to +external Guile modules or to extra files. If you want +@file{configuration.scm} to be self-contained, we recommend that modules +or files it refers to be part of a channel. + +Besides, provenance meta-data is ``silent'' in the sense that it does +not change the bits contained in your system, @emph{except for the +meta-data bits themselves}. Two different OS configurations or sets of +channels can lead to the same system, bit-for-bit; when +@code{provenance-service-type} is used, these two systems will have +different meta-data and thus different store file names, which makes +comparison less trivial. +@end quotation +@end defvr @node Shepherd Services @subsection Shepherd Services -- cgit v1.2.3