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: [PATCH] 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 ++++++++++++++++++++++++ gnu/services.scm | 87 ++++++++++++++++++++++++++++++++++++++++++++++++ gnu/system.scm | 10 ++++++ 3 files changed, 141 insertions(+) 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 diff --git a/gnu/services.scm b/gnu/services.scm index 394470ba7d..e7a3a95e43 100644 --- a/gnu/services.scm +++ b/gnu/services.scm @@ -25,6 +25,8 @@ (define-module (gnu services) #:use-module (guix profiles) #:use-module (guix discovery) #:use-module (guix combinators) + #:use-module (guix channels) + #:use-module (guix describe) #:use-module (guix sets) #:use-module (guix ui) #:use-module ((guix utils) #:select (source-properties->location)) @@ -39,6 +41,7 @@ (define-module (gnu services) #:use-module (srfi srfi-35) #:use-module (ice-9 vlist) #:use-module (ice-9 match) + #:autoload (ice-9 pretty-print) (pretty-print) #:export (service-extension service-extension? service-extension-target @@ -82,6 +85,7 @@ (define-module (gnu services) ambiguous-target-service-error-target-type system-service-type + provenance-service-type boot-service-type cleanup-service-type activation-service-type @@ -370,6 +374,89 @@ (define %boot-service ;; The service that produces the boot script. (service boot-service-type #t)) + +;;; +;;; Provenance tracking. +;;; + +(define (object->pretty-string obj) + "Like 'object->string', but using 'pretty-print'." + (call-with-output-string + (lambda (port) + (pretty-print obj port)))) + +(define (channel->code channel) + "Return code to build CHANNEL, ready to be dropped in a 'channels.scm' +file." + `(channel (name ',(channel-name channel)) + (url ,(channel-url channel)) + (branch ,(channel-branch channel)) + (commit ,(channel-commit channel)))) + +(define (channel->sexp channel) + "Return an sexp describing CHANNEL. The sexp is _not_ code and is meant to +be parsed by tools; it's potentially more future-proof than code." + `(channel (name ,(channel-name channel)) + (url ,(channel-url channel)) + (branch ,(channel-branch channel)) + (commit ,(channel-commit channel)))) + +(define (provenance-file channels config-file) + "Return a 'provenance' file describing CHANNELS, a list of channels, and +CONFIG-FILE, which can be either #f or a containing the OS +configuration being used." + (scheme-file "provenance" + #~(provenance + (version 0) + (channels #+@(if channels + (map channel->sexp channels) + '())) + (configuration-file #+config-file)))) + +(define (provenance-entry config-file) + "Return system entries describing the operating system provenance: the +channels in use and CONFIG-FILE, if it is true." + (define profile + (current-profile)) + + (define channels + (and=> profile profile-channels)) + + (mbegin %store-monad + (let ((config-file (cond ((string? config-file) + (local-file config-file "configuration.scm")) + ((not config-file) + #f) + (else + config-file)))) + (return `(("provenance" ,(provenance-file channels config-file)) + ,@(if channels + `(("channels.scm" + ,(plain-file "channels.scm" + (object->pretty-string + `(list + ,@(map channel->code channels)))))) + '()) + ,@(if config-file + `(("configuration.scm" ,config-file)) + '())))))) + +(define provenance-service-type + (service-type (name 'provenance) + (extensions + (list (service-extension system-service-type + provenance-entry))) + (default-value #f) ;the OS config file + (description + "Store provenance information about the system in the system +itself: the channels used when building the system, and its configuration +file, when available."))) + + +;;; +;;; Cleanup. +;;; + (define (cleanup-gexp _) "Return a gexp to clean up /tmp and similar places upon boot." (with-imported-modules '((guix build utils)) diff --git a/gnu/system.scm b/gnu/system.scm index 96c2b5aad3..abdbb081e6 100644 --- a/gnu/system.scm +++ b/gnu/system.scm @@ -110,6 +110,7 @@ (define-module (gnu system) system-linux-image-file-name operating-system-with-gc-roots + operating-system-with-provenance boot-parameters boot-parameters? @@ -540,6 +541,15 @@ (define (operating-system-with-gc-roots os roots) gc-root-service-type roots) (operating-system-user-services os))))) +(define* (operating-system-with-provenance os #:optional config-file) + "Return a variant of OS that stores its own provenance information, +including CONFIG-FILE, if available. This is achieved by adding an instance +of PROVENANCE-SERVICE-TYPE to its services." + (operating-system + (inherit os) + (services (cons (service provenance-service-type config-file) + (operating-system-user-services os))))) + ;;; ;;; /etc.