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| -rw-r--r-- | doc/guix.texi | 113 | ||||
| -rw-r--r-- | gnu/services/admin.scm | 140 |
2 files changed, 251 insertions, 2 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index ca96ecc298..d45deed21e 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -12926,6 +12926,7 @@ declaration. * Scheduled Job Execution:: The mcron service. * Log Rotation:: The rottlog service. * Networking Services:: Network setup, SSH daemon, etc. +* Unattended Upgrades:: Automated system upgrades. * X Window:: Graphical display. * Printing Services:: Local and remote printer support. * Desktop Services:: D-Bus and desktop services. @@ -15298,6 +15299,117 @@ Use this to add additional options and manage shared secrets out-of-band. @end table @end deftp +@node Unattended Upgrades +@subsection Unattended Upgrades + +@cindex unattended upgrades +@cindex upgrades, unattended +Guix provides a service to perform @emph{unattended upgrades}: +periodically, the system automatically reconfigures itself from the +latest Guix. Guix System has several properties that make unattended +upgrades safe: + +@itemize +@item +upgrades are transactional (either the upgrade succeeds or it fails, but +you cannot end up with an ``in-between'' system state); +@item +the upgrade log is kept---you can view it with @command{guix system +list-generations}---and you can roll back to any previous generation, +should the upgraded system fail to behave as intended; +@item +channel code is authenticated so you know you can only run genuine code +(@pxref{Channels}); +@item +@command{guix system reconfigure} prevents downgrades, which makes it +immune to @dfn{downgrade attacks}. +@end itemize + +To set up unattended upgrades, add an instance of +@code{unattended-upgrade-service-type} like the one below to the list of +your operating system services: + +@lisp +(service unattended-upgrade-service-type) +@end lisp + +The defaults above set up weekly upgrades: every Sunday at midnight. +You do not need to provide the operating system configuration file: it +uses @file{/run/current-system/configuration.scm}, which ensures it +always uses your latest configuration---@pxref{provenance-service-type}, +for more information about this file. + +There are several things that can be configured, in particular the +periodicity and services (daemons) to be restarted upon completion. +When the upgrade is successful, the service takes care of deleting +system generations older that some threshold, as per @command{guix +system delete-generations}. See the reference below for details. + +To ensure that upgrades are actually happening, you can run +@command{guix system describe}. To investigate upgrade failures, visit +the unattended upgrade log file (see below). + +@defvr {Scheme Variable} unattended-upgrade-service-type +This is the service type for unattended upgrades. It sets up an mcron +job (@pxref{Scheduled Job Execution}) that runs @command{guix system +reconfigure} from the latest version of the specified channels. + +Its value must be a @code{unattended-upgrade-configuration} record (see +below). +@end defvr + +@deftp {Data Type} unattended-upgrade-configuration +This data type represents the configuration of the unattended upgrade +service. The following fields are available: + +@table @asis +@item @code{schedule} (default: @code{"30 01 * * 0"}) +This is the schedule of upgrades, expressed as a gexp containing an +mcron job schedule (@pxref{Guile Syntax, mcron job specifications,, +mcron, GNU@tie{}mcron}). + +@item @code{channels} (default: @code{#~%default-channels}) +This gexp specifies the channels to use for the upgrade +(@pxref{Channels}). By default, the tip of the official @code{guix} +channel is used. + +@item @code{services-to-restart} (default: @code{'(mcron)}) +This field specifies the Shepherd services to restart when the upgrade +completes. + +Those services are restarted right away upon completion, as with +@command{herd restart}, which ensures that the latest version is +running---remember that by default @command{guix system reconfigure} +only restarts services that are not currently running, which is +conservative: it minimizes disruption but leaves outdated services +running. + +By default, the @code{mcron} service is restarted. This ensures that +the latest version of the unattended upgrade job will be used next time. + +@item @code{system-expiration} (default: @code{(* 3 30 24 3600)}) +This is the expiration time in seconds for system generations. System +generations older that this amount of time are deleted with +@command{guix system delete-generations} when an upgrade completes. + +@quotation Note +The unattended upgrade service does not run the garbage collector. You +will probably want to set up your own mcron job to run @command{guix gc} +periodically. +@end quotation + +@item @code{maximum-duration} (default: @code{3600}) +Maximum duration in seconds for the upgrade; past that time, the upgrade +aborts. + +This is primarily useful to ensure the upgrade does not end up +rebuilding or re-downloading ``the world''. + +@item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"}) +File where unattended upgrades are logged. +@end table +@end deftp + @node X Window @subsection X Window @@ -29628,6 +29740,7 @@ extend it by passing it lists of packages to add to the system profile. @end defvr @cindex provenance tracking, of the operating system +@anchor{provenance-service-type} @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 diff --git a/gnu/services/admin.scm b/gnu/services/admin.scm index 89fa73920d..6ed3de9423 100644 --- a/gnu/services/admin.scm +++ b/gnu/services/admin.scm @@ -1,6 +1,6 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org> -;;; Copyright © 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org> +;;; Copyright © 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org> ;;; Copyright © 2020 Brice Waegeneire <brice@waegenei.re> ;;; ;;; This file is part of GNU Guix. @@ -20,10 +20,13 @@ (define-module (gnu services admin) #:use-module (gnu packages admin) + #:use-module (gnu packages certs) + #:use-module (gnu packages package-management) #:use-module (gnu services) #:use-module (gnu services mcron) #:use-module (gnu services shepherd) #:use-module (guix gexp) + #:use-module (guix modules) #:use-module (guix packages) #:use-module (guix records) #:use-module (srfi srfi-1) @@ -41,7 +44,17 @@ rottlog-configuration rottlog-configuration? rottlog-service - rottlog-service-type)) + rottlog-service-type + + unattended-upgrade-service-type + unattended-upgrade-configuration + unattended-upgrade-configuration? + unattended-upgrade-configuration-channels + unattended-upgrade-configuration-schedule + unattended-upgrade-configuration-services-to-restart + unattended-upgrade-configuration-system-expiration + unattended-upgrade-configuration-maximum-duration + unattended-upgrade-configuration-log-file)) ;;; Commentary: ;;; @@ -177,4 +190,127 @@ Old log files are removed or compressed according to the configuration.") rotations))))) (default-value (rottlog-configuration)))) + +;;; +;;; Unattended upgrade. +;;; + +(define-record-type* <unattended-upgrade-configuration> + unattended-upgrade-configuration make-unattended-upgrade-configuration + unattended-upgrade-configuration? + (schedule unattended-upgrade-configuration-schedule + (default "30 01 * * 0")) + (channels unattended-upgrade-configuration-channels + (default #~%default-channels)) + (services-to-restart unattended-upgrade-configuration-services-to-restart + (default '(mcron))) + (system-expiration unattended-upgrade-system-expiration + (default (* 3 30 24 3600))) + (maximum-duration unattended-upgrade-maximum-duration + (default 3600)) + (log-file unattended-upgrade-configuration-log-file + (default %unattended-upgrade-log-file))) + +(define %unattended-upgrade-log-file + "/var/log/unattended-upgrade.log") + +(define (unattended-upgrade-mcron-jobs config) + (define channels + (scheme-file "channels.scm" + (unattended-upgrade-configuration-channels config))) + + (define log + (unattended-upgrade-configuration-log-file config)) + + (define services + (unattended-upgrade-configuration-services-to-restart config)) + + (define expiration + (unattended-upgrade-system-expiration config)) + + (define code + (with-imported-modules (source-module-closure '((guix build utils) + (gnu services herd))) + #~(begin + (use-modules (guix build utils) + (gnu services herd) + (srfi srfi-19) + (srfi srfi-34)) + + (define log + (open-file #$log "a0")) + + (define (timestamp) + (date->string (time-utc->date (current-time time-utc)) + "[~4]")) + + (define (alarm-handler . _) + (format #t "~a time is up, aborting upgrade~%" + (timestamp)) + (exit 1)) + + (define-syntax-rule (with-logging exp ...) + (with-output-to-port log + (lambda () + (with-error-to-port log + (lambda () + exp ...))))) + + ;; 'guix time-machine' needs X.509 certificates to authenticate the + ;; Git host. + (setenv "SSL_CERT_DIR" + #$(file-append nss-certs "/etc/ssl/certs")) + + ;; Make sure the upgrade doesn't take too long. + (sigaction SIGALRM alarm-handler) + (alarm #$(unattended-upgrade-maximum-duration config)) + + (with-logging + (format #t "~a starting upgrade...~%" (timestamp)) + (guard (c ((invoke-error? c) + (report-invoke-error c))) + (invoke #$(file-append guix "/bin/guix") + "time-machine" "-C" #$channels + "--" "system" "reconfigure" + "/run/current-system/configuration.scm") + + ;; 'guix system delete-generations' fails when there's no + ;; matching generation. Thus, catch 'invoke-error?'. + (guard (c ((invoke-error? c) + (report-invoke-error c))) + (invoke #$(file-append guix "/bin/guix") + "system" "delete-generations" + #$(string-append (number->string expiration) + "s"))) + + (format #t "~a restarting services...~%" (timestamp)) + (for-each restart-service '#$services) + + ;; XXX: If 'mcron' has been restarted, perhaps this isn't + ;; reached. + (format #t "~a upgrade complete~%" (timestamp))))))) + + (define upgrade + (program-file "unattended-upgrade" code)) + + (list #~(job #$(unattended-upgrade-configuration-schedule config) + #$upgrade))) + +(define (unattended-upgrade-log-rotations config) + (list (log-rotation + (files + (list (unattended-upgrade-configuration-log-file config)))))) + +(define unattended-upgrade-service-type + (service-type + (name 'unattended-upgrade) + (extensions + (list (service-extension mcron-service-type + unattended-upgrade-mcron-jobs) + (service-extension rottlog-service-type + unattended-upgrade-log-rotations))) + (description + "Periodically upgrade the system from the current configuration.") + (default-value (unattended-upgrade-configuration)))) + ;;; admin.scm ends here |