[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 08/10] Implement switch-generation and roll-back
From: |
cmmarusich |
Subject: |
[PATCH 08/10] Implement switch-generation and roll-back |
Date: |
Fri, 28 Oct 2016 03:07:25 -0700 |
From: Chris Marusich <address@hidden>
* guix/scripts/system.scm (roll-back-system, switch-to-system-generation,
reinstall-grub): New procedures.
* guix/scripts/system.scm (show-help, process-command, guix-system): Add
references to the new actions.
---
guix/scripts/system.scm | 97 ++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 91 insertions(+), 6 deletions(-)
diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 2c80c2e..086b431 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -407,6 +407,67 @@ NUMBERS, which is a list of generation numbers."
;;;
+;;; Roll-back.
+;;;
+(define (roll-back-system store)
+ "Roll back the system profile to its previous generation."
+ (switch-to-system-generation store "-1"))
+
+;;;
+;;; Switch generations.
+;;;
+(define (switch-to-system-generation store spec)
+ "Switch the system profile to the generation specified by SPEC, and
+re-install grub with a grub configuration file that uses the specified system
+generation as its default entry."
+ (let ((number (relative-generation-spec->number %system-profile spec)))
+ (if number
+ (begin
+ (reinstall-grub store number)
+ (switch-to-generation* %system-profile number))
+ (leave (_ "cannot switch to system generation '~a'~%") spec))))
+
+(define (reinstall-grub store number)
+ "Re-install grub for existing system profile generation NUMBER."
+ (let* ((generation (generation-file-name %system-profile number))
+ (file (string-append generation "/parameters"))
+ (params (unless-file-not-found
+ (call-with-input-file file read-boot-parameters)))
+ (root-device (boot-parameters-root-device params))
+ (store-mount-point (boot-parameters-store-fs-mount-point params))
+ (grub-root-search-device (boot-parameters-store-device params))
+ ;; We don't currently keep track of past menu entries' details. The
+ ;; default values will allow the system to boot, even if they differ
+ ;; from the actual past values for this generation's entry.
+ (grub-config (grub-configuration (device root-device)))
+ ;; Make the specified system generation the default entry.
+ (entries (grub-entries %system-profile (list number)))
+ (old-generations (delv number (generation-numbers %system-profile)))
+ (old-entries (grub-entries %system-profile old-generations))
+ (grub.cfg (run-with-store store
+ (grub-configuration-file grub-config
+ store-mount-point
+ grub-root-search-device
+ entries
+ #:old-entries old-entries))))
+ (show-what-to-build store (list grub.cfg))
+ (build-derivations store (list grub.cfg))
+ ;; This is basically the same as install-grub*, but for now we avoid
+ ;; re-installing the GRUB boot loader itself onto a device, mainly because
+ ;; we don't in general have access to the same version of the GRUB package
+ ;; which was used when installing this other system generation.
+ (let* ((grub.cfg-path (derivation->output-path grub.cfg))
+ (gc-root (string-append %gc-roots-directory "/grub.cfg"))
+ (temp-gc-root (string-append gc-root ".new")))
+ (switch-symlinks temp-gc-root grub.cfg-path)
+ (unless (false-if-exception (install-grub-config grub.cfg-path "/"))
+ (delete-file temp-gc-root)
+ (leave (_ "failed to re-install GRUB configuration file: '~a'~%")
+ grub.cfg-path))
+ (rename-file temp-gc-root gc-root))))
+
+
+;;;
;;; Graphs.
;;;
@@ -641,14 +702,19 @@ building anything."
;;;
(define (show-help)
- (display (_ "Usage: guix system [OPTION] ACTION [FILE]
-Build the operating system declared in FILE according to ACTION.\n"))
+ (display (_ "Usage: guix system [OPTION ...] ACTION [ARG ...] [FILE]
+Build the operating system declared in FILE according to ACTION.
+Some ACTIONS support additional ARGS.\n"))
(newline)
(display (_ "The valid values for ACTION are:\n"))
(newline)
(display (_ "\
reconfigure switch to a new operating system configuration\n"))
(display (_ "\
+ roll-back switch to the previous operating system configuration\n"))
+ (display (_ "\
+ switch-generation switch to an existing operating system configuration\n"))
+ (display (_ "\
list-generations list the system generations\n"))
(display (_ "\
build build the operating system without installing anything\n"))
@@ -809,15 +875,33 @@ resulting from command-line parsing."
"Process COMMAND, one of the 'guix system' sub-commands. ARGS is its
argument list and OPTS is the option alist."
(case command
+ ;; The following commands do not need to use the store, and they do not
need
+ ;; an operating system configuration file.
((list-generations)
- ;; List generations. No need to connect to the daemon, etc.
(let ((pattern (match args
(() "")
((pattern) pattern)
(x (leave (_ "wrong number of arguments~%"))))))
(list-generations pattern)))
- (else
- (process-action command args opts))))
+ ;; The following commands need to use the store, but they do not need an
+ ;; operating system configuration file.
+ ((switch-generation)
+ (let ((pattern (match args
+ ((pattern) pattern)
+ (x (leave (_ "wrong number of arguments~%"))))))
+ (with-store store
+ (set-build-options-from-command-line store opts)
+ (switch-to-system-generation store pattern))))
+ ((roll-back)
+ (let ((pattern (match args
+ (() "")
+ (x (leave (_ "wrong number of arguments~%"))))))
+ (with-store store
+ (set-build-options-from-command-line store opts)
+ (roll-back-system store))))
+ ;; The following commands need to use the store, and they also
+ ;; need an operating system configuration file.
+ (else (process-action command args opts))))
(define (guix-system . args)
(define (parse-sub-command arg result)
@@ -827,7 +911,8 @@ argument list and OPTS is the option alist."
(let ((action (string->symbol arg)))
(case action
((build container vm vm-image disk-image reconfigure init
- extension-graph shepherd-graph list-generations)
+ extension-graph shepherd-graph list-generations roll-back
+ switch-generation)
(alist-cons 'action action result))
(else (leave (_ "~a: unknown action~%") action))))))
--
2.9.2
- Re: [PATCH 01/10] * gnu/system.scm (<boot-parameters>): Add 'store-device' and 'store-fs-mount-point'., (continued)
[PATCH 05/10] Rename previous-grub-entries to grub-entries, cmmarusich, 2016/10/28
[PATCH 07/10] Factor out procedure: install-grub-config, cmmarusich, 2016/10/28
[PATCH 06/10] grub-entries: take a list of numbers on input, cmmarusich, 2016/10/28
[PATCH 03/10] Refactor grub.cfg generation logic, cmmarusich, 2016/10/28
[PATCH 09/10] Rename grub-entries to profile-grub-entries, cmmarusich, 2016/10/28
[PATCH 02/10] Add 'device' field to <menu-entry>, cmmarusich, 2016/10/28
[PATCH 04/10] Extract procedure: relative-generation-spec->number, cmmarusich, 2016/10/28
[PATCH 10/10] Mention new 'guix system' features in the manual, cmmarusich, 2016/10/28
[PATCH 08/10] Implement switch-generation and roll-back,
cmmarusich <=
Re: Add system roll-back and switch-generation commands, Ludovic Courtès, 2016/10/29