guix system: Add 'reconfigure' action.

* guix/scripts/system.scm (%system-profile): New variable.
  (switch-to-system, previous-grub-entries): New procedures.
  (unless-file-not-found): New macro.
  (show-help): Add 'reconfigure'.
  (guix-system): Handle it.
* gnu/system.scm: Export 'operating-system-activation-script'.
* doc/guix.texi (Invoking guix system): Document it.
This commit is contained in:
Ludovic Courtès 2014-06-27 00:06:46 +02:00
parent f01efec09a
commit b25937e318
3 changed files with 114 additions and 20 deletions

View File

@ -3210,6 +3210,18 @@ operating system is instantiate. Currently the following values are
supported:
@table @code
@item reconfigure
Build the operating system described in @var{file}, activate it, and
switch to it@footnote{This action is usable only on systems already
running GNU.}.
This effects all the configuration specified in @var{file}: user
accounts, system services, global package list, setuid programs, etc.
It also adds a GRUB menu entry for the new OS configuration, and moves
entries for older configurations to a submenu---unless
@option{--no-grub} is passed.
@item build
Build the operating system's derivation, which includes all the
configuration files and programs needed to boot and run the system.

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@ -59,6 +59,7 @@
operating-system-timezone
operating-system-locale
operating-system-file-systems
operating-system-activation-script
operating-system-derivation
operating-system-profile

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@ -17,6 +17,7 @@
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix scripts system)
#:use-module (guix config)
#:use-module (guix ui)
#:use-module (guix store)
#:use-module (guix gexp)
@ -24,6 +25,7 @@
#:use-module (guix packages)
#:use-module (guix utils)
#:use-module (guix monads)
#:use-module (guix profiles)
#:use-module (guix scripts build)
#:use-module (guix build utils)
#:use-module (guix build install)
@ -120,6 +122,70 @@ When GRUB? is true, install GRUB on DEVICE, using GRUB.CFG."
(unless (false-if-exception (install-grub grub.cfg device target))
(leave (_ "failed to install GRUB on device '~a'~%") device))))
;;;
;;; Reconfiguration.
;;;
(define %system-profile
;; The system profile.
(string-append %state-directory "/profiles/system"))
(define* (switch-to-system store os system
#:optional (profile %system-profile))
"Make a new generation of PROFILE pointing to SYSTEM, which is the directory
corresponding to OS, switch to it atomically, and then run OS's activation
script."
(let* ((number (+ 1 (generation-number profile)))
(generation (generation-file-name profile number)))
(symlink system generation)
(switch-symlinks profile generation)
(run-with-store store
(mlet %store-monad ((script (operating-system-activation-script os)))
(format #t (_ "activating system...~%"))
(return (primitive-load (derivation->output-path script)))))
;; TODO: Run 'deco reload ...'.
))
(define-syntax-rule (unless-file-not-found exp)
(catch 'system-error
(lambda ()
exp)
(lambda args
(if (= ENOENT (system-error-errno args))
#f
(apply throw args)))))
(define* (previous-grub-entries #:optional (profile %system-profile))
"Return a list of 'menu-entry' for the generations of PROFILE."
(define (system->grub-entry system)
(unless-file-not-found
(call-with-input-file (string-append system "/parameters")
(lambda (port)
(match (read port)
(('boot-parameters ('version 0)
('label label) ('root-device root)
('kernel linux)
_ ...)
(menu-entry
(label label)
(linux linux)
(linux-arguments
(list (string-append "--root=" root)
#~(string-append "--system=" #$system)
#~(string-append "--load=" #$system "/boot")))
(initrd #~(string-append #$system "/initrd"))))
(_ ;unsupported format
(warning (_ "unrecognized boot parameters for '~a'~%")
system)
#f))))))
(let ((systems (map (cut generation-file-name profile <>)
(generation-numbers profile))))
(filter-map system->grub-entry systems)))
;;;
;;; Options.
@ -131,6 +197,8 @@ Build the operating system declared in FILE according to ACTION.\n"))
(newline)
(display (_ "The valid values for ACTION are:\n"))
(display (_ "\
- 'reconfigure', switch to a new operating system configuration\n"))
(display (_ "\
- 'build', build the operating system without installing anything\n"))
(display (_ "\
- 'vm', build a virtual machine image that shares the host's store\n"))
@ -201,7 +269,7 @@ Build the operating system declared in FILE according to ACTION.\n"))
(alist-cons 'argument arg result)
(let ((action (string->symbol arg)))
(case action
((build vm vm-image disk-image init)
((build vm vm-image disk-image reconfigure init)
(alist-cons 'action action result))
(else (leave (_ "~a: unknown action~%")
action))))))
@ -224,7 +292,7 @@ Build the operating system declared in FILE according to ACTION.\n"))
action))
(case action
((build vm vm-image disk-image)
((build vm vm-image disk-image reconfigure)
(unless (= count 1)
(fail)))
((init)
@ -241,7 +309,7 @@ Build the operating system declared in FILE according to ACTION.\n"))
(read-operating-system file)
(leave (_ "no configuration file specified~%"))))
(mdrv (case action
((build init)
((build init reconfigure)
(operating-system-derivation os))
((vm-image)
(let ((size (assoc-ref opts 'image-size)))
@ -257,8 +325,9 @@ Build the operating system declared in FILE according to ACTION.\n"))
(dry? (assoc-ref opts 'dry-run?))
(drv (run-with-store store mdrv))
(grub? (assoc-ref opts 'install-grub?))
(old (previous-grub-entries))
(grub.cfg (run-with-store store
(operating-system-grub.cfg os)))
(operating-system-grub.cfg os old)))
(grub (package-derivation store grub))
(drv-lst (if grub?
(list drv grub grub.cfg)
@ -273,21 +342,33 @@ Build the operating system declared in FILE according to ACTION.\n"))
(display (derivation->output-path drv))
(newline)
(when (eq? action 'init)
(let* ((target (second args))
(device (grub-configuration-device
(operating-system-bootloader os))))
(format #t (_ "initializing operating system under '~a'...~%")
target)
;; Make sure GRUB is accessible.
(when grub
(let ((prefix (derivation->output-path grub)))
(setenv "PATH"
(string-append prefix "/bin:" prefix "/sbin:"
(getenv "PATH")))))
(when grub
(let ((prefix (derivation->output-path grub)))
(setenv "PATH"
(string-append prefix "/bin:" prefix "/sbin:"
(getenv "PATH")))))
(let ((target (match args
((first second) second)
(_ #f)))
(device (and grub?
(grub-configuration-device
(operating-system-bootloader os)))))
(case action
((reconfigure)
(switch-to-system store os (derivation->output-path drv))
(when grub?
(unless (install-grub grub.cfg device target)
(leave (_ "failed to install GRUB on device '~a'~%") device))))
((init)
(format #t (_ "initializing operating system under '~a'...~%")
target)
(install store (derivation->output-path drv)
(canonicalize-path target)
#:grub? grub?
#:grub.cfg (derivation->output-path grub.cfg)
#:device device)))))))
(install store (derivation->output-path drv)
(canonicalize-path target)
#:grub? grub?
#:grub.cfg (derivation->output-path grub.cfg)
#:device device))))))))
;;; system.scm ends here