Toggle diff (187 lines)
diff --git a/doc/guix.texi b/doc/guix.texi
index fd40b6535f..3dc2fd1318 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -25839,6 +25839,15 @@ switch to it@footnote{This action (and the related actions
@code{switch-generation} and @code{roll-back}) are usable only on
systems already running Guix System.}.
+@quotation Note
+@c The paragraph below refers to the problem discussed at
+@c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
+It is highly recommended to run @command{guix pull} once before you run
+@command{guix system reconfigure} for the first time (@pxref{Invoking
+guix pull}). Failing to do that you would see an older version of Guix
+once @command{reconfigure} has completed.
+@end quotation
+
This effects all the configuration specified in @var{file}: user
accounts, system services, global package list, setuid programs, etc.
The command starts system services specified in @var{file} that are not
@@ -25857,14 +25866,27 @@ It also adds a bootloader menu entry for the new OS configuration,
entries for older configurations to a submenu, allowing you to choose
an older system generation at boot time should you need it.
-@quotation Note
-@c The paragraph below refers to the problem discussed at
-@c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
-It is highly recommended to run @command{guix pull} once before you run
-@command{guix system reconfigure} for the first time (@pxref{Invoking
-guix pull}). Failing to do that you would see an older version of Guix
-once @command{reconfigure} has completed.
-@end quotation
+@cindex provenance tracking, of the operating system
+Upon completion, the new system is deployed under
+@file{/run/current-system}. This directory contains @dfn{provenance
+meta-data}: the list of channels in use (@pxref{Channels}) and
+@var{file} itself, when available. This information is useful should
+you later want to inspect how this particular generation was built.
+
+In fact, assuming @var{file} is self-contained, you can later rebuild
+generation @var{n} of your operating system with:
+
+@example
+guix time-machine \
+ -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
+ system reconfigure \
+ /var/guix/profiles/system-@var{n}-link/configuration.scm
+@end example
+
+You can think of it as some sort of built-in version control! Your
+system is not just a binary artifact: @emph{it carries its own source}.
+@xref{Service Reference, @code{provenance-service-type}}, for more
+information on provenance tracking.
@item switch-generation
@cindex generations
@@ -26126,6 +26148,25 @@ This works as per @command{guix build} (@pxref{Invoking guix build}).
Return the derivation file name of the given operating system without
building anything.
+@cindex provenance tracking, of the operating system
+@item --save-provenance
+As discussed above, @command{guix system init} and @command{guix system
+reconfigure} always save provenance information @i{via} a dedicated
+service (@pxref{Service Reference, @code{provenance-service-type}}).
+However, other commands don't do that by default. If you wish to, say,
+create a virtual machine image that contains provenance information, you
+can run:
+
+@example
+guix system vm-image --save-provenance config.scm
+@end example
+
+That way, the resulting image will effectively ``embed its own source''
+in the form of meta-data in @file{/run/current-system}. With that
+information, one can rebuild the image to make sure it really contains
+what it pretends to contain; or they could use that to derive a variant
+of the image.
+
@item --file-system-type=@var{type}
@itemx -t @var{type}
For the @code{disk-image} action, create a file system of the given
@@ -27013,6 +27054,10 @@ channels can lead to the same system, bit-for-bit; when
different meta-data and thus different store file names, which makes
comparison less trivial.
@end quotation
+
+This service is automatically added to your operating system
+configuration when you use @command{guix system reconfigure} or
+@command{guix system init}.
@end defvr
@node Shepherd Services
diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index e49c9d36b9..b22945658e 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -722,7 +722,9 @@ and TARGET arguments."
(return (primitive-eval (lowered-gexp-sexp lowered))))))
(define* (perform-action action os
- #:key skip-safety-checks?
+ #:key
+ save-provenance?
+ skip-safety-checks?
install-bootloader?
dry-run? derivations-only?
use-substitutes? bootloader-target target
@@ -917,16 +919,18 @@ Some ACTIONS support additional ARGS.\n"))
--image-size=SIZE for 'vm-image', produce an image of SIZE"))
(display (G_ "
--no-bootloader for 'init', do not install a bootloader"))
+ (display (G_ "
+ --save-provenance save provenance information"))
(display (G_ "
--share=SPEC for 'vm', share host file system according to SPEC"))
+ (display (G_ "
+ --expose=SPEC for 'vm', expose host file system according to SPEC"))
(display (G_ "
-N, --network for 'container', allow containers to access the network"))
(display (G_ "
-r, --root=FILE for 'vm', 'vm-image', 'disk-image', 'container',
and 'build', make FILE a symlink to the result, and
register it as a garbage collector root"))
- (display (G_ "
- --expose=SPEC for 'vm', expose host file system according to SPEC"))
(display (G_ "
--full-boot for 'vm', make a full boot sequence"))
(display (G_ "
@@ -977,6 +981,9 @@ Some ACTIONS support additional ARGS.\n"))
(option '("full-boot") #f #f
(lambda (opt name arg result)
(alist-cons 'full-boot? #t result)))
+ (option '("save-provenance") #f #f
+ (lambda (opt name arg result)
+ (alist-cons 'save-provenance? #t result)))
(option '("skip-checks") #f #f
(lambda (opt name arg result)
(alist-cons 'skip-safety-checks? #t result)))
@@ -1040,24 +1047,32 @@ resulting from command-line parsing."
file-or-exp))
obj)
+ (define save-provenance?
+ (or (assoc-ref opts 'save-provenance?)
+ (memq action '(init reconfigure))))
+
(let* ((file (match args
(() #f)
((x . _) x)))
(expr (assoc-ref opts 'expression))
(system (assoc-ref opts 'system))
- (os (ensure-operating-system
- (or file expr)
- (cond
- ((and expr file)
- (leave
- (G_ "both file and expression cannot be specified~%")))
- (expr
- (read/eval expr))
- (file
- (load* file %user-module
- #:on-error (assoc-ref opts 'on-error)))
- (else
- (leave (G_ "no configuration specified~%"))))))
+ (transform (if save-provenance?
+ (cut operating-system-with-provenance <> file)
+ identity))
+ (os (transform
+ (ensure-operating-system
+ (or file expr)
+ (cond
+ ((and expr file)
+ (leave
+ (G_ "both file and expression cannot be specified~%")))
+ (expr
+ (read/eval expr))
+ (file
+ (load* file %user-module
+ #:on-error (assoc-ref opts 'on-error)))
+ (else
+ (leave (G_ "no configuration specified~%")))))))
(dry? (assoc-ref opts 'dry-run?))
(bootloader? (assoc-ref opts 'install-bootloader?))
--
2.24.0