From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:470:142:3::10]:37841) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvT3Q-00027K-3U for guix-patches@gnu.org; Wed, 07 Aug 2019 17:01:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hvT3O-0004gJ-DQ for guix-patches@gnu.org; Wed, 07 Aug 2019 17:01:04 -0400 Received: from debbugs.gnu.org ([209.51.188.43]:58971) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hvT3O-0004g6-9E for guix-patches@gnu.org; Wed, 07 Aug 2019 17:01:02 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1hvT3O-0008MD-6m for guix-patches@gnu.org; Wed, 07 Aug 2019 17:01:02 -0400 Subject: [bug#36952] [PATCH v2] machine: Implement 'roll-back-machine'. Resent-Message-ID: From: zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) References: <87v9v94067.fsf@sdf.lonestar.org> <87v9v8ohvq.fsf@dustycloud.org> Date: Wed, 07 Aug 2019 16:57:06 -0400 In-Reply-To: <87v9v8ohvq.fsf@dustycloud.org> (Christopher Lemmer Webber's message of "Wed, 07 Aug 2019 16:11:37 -0400") Message-ID: <87v9v8k82l.fsf_-_@sdf.lonestar.org> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-patches-bounces+kyle=kyleam.com@gnu.org Sender: "Guix-patches" To: Christopher Lemmer Webber Cc: 36952@debbugs.gnu.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable * gnu/machine.scm (roll-back-machine, &deploy-error, deploy-error?) (deploy-error-should-roll-back) (deploy-error-captured-args): New variable. * gnu/machine/ssh.scm (roll-back-managed-host): New variable. * guix/scripts/deploy.scm (guix-deploy): Roll-back systems when a deployment fails. =2D-- gnu/machine.scm | 27 ++++++++++++++- gnu/machine/ssh.scm | 75 +++++++++++++++++++++++++++++++++++++++-- guix/remote.scm | 1 + guix/scripts/deploy.scm | 17 ++++++++-- 4 files changed, 114 insertions(+), 6 deletions(-) diff --git a/gnu/machine.scm b/gnu/machine.scm index 30ae97f6ec..05b03b21d4 100644 =2D-- a/gnu/machine.scm +++ b/gnu/machine.scm @@ -24,6 +24,7 @@ #:use-module (guix records) #:use-module (guix store) #:use-module ((guix utils) #:select (source-properties->location)) + #:use-module (srfi srfi-35) #:export (environment-type environment-type? environment-type-name @@ -40,7 +41,13 @@ machine-display-name =20 deploy-machine =2D machine-remote-eval)) + roll-back-machine + machine-remote-eval + + &deploy-error + deploy-error? + deploy-error-should-roll-back + deploy-error-captured-args)) =20 ;;; Commentary: ;;; @@ -66,6 +73,7 @@ ;; of the form '(machine-remote-eval machine exp)'. (machine-remote-eval environment-type-machine-remote-eval) ; procedure (deploy-machine environment-type-deploy-machine) ; procedure + (roll-back-machine environment-type-roll-back-machine) ; procedure =20 ;; Metadata. (name environment-type-name) ; symbol @@ -105,3 +113,20 @@ are built and deployed to MACHINE beforehand." MACHINE, activating it on MACHINE and switching MACHINE to the new generat= ion." (let ((environment (machine-environment machine))) ((environment-type-deploy-machine environment) machine))) + +(define (roll-back-machine machine) + "Monadic procedure rolling back to the previous system generation on +MACHINE. Return the number of the generation that was current before switc= hing +and the new generation number." + (let ((environment (machine-environment machine))) + ((environment-type-roll-back-machine environment) machine))) + + +;;; +;;; Error types. +;;; + +(define-condition-type &deploy-error &error + deploy-error? + (should-roll-back deploy-error-should-roll-back) + (captured-args deploy-error-captured-args)) diff --git a/gnu/machine/ssh.scm b/gnu/machine/ssh.scm index 274d56db26..ae312597dd 100644 =2D-- a/gnu/machine/ssh.scm +++ b/gnu/machine/ssh.scm @@ -17,6 +17,7 @@ ;;; along with GNU Guix. If not, see . =20 (define-module (gnu machine ssh) + #:use-module (gnu bootloader) #:use-module (gnu machine) #:autoload (gnu packages gnupg) (guile-gcrypt) #:use-module (gnu system) @@ -34,8 +35,10 @@ #:use-module (guix store) #:use-module (guix utils) #:use-module (ice-9 match) + #:use-module (srfi srfi-1) #:use-module (srfi srfi-19) #:use-module (srfi srfi-26) + #:use-module (srfi srfi-34) #:use-module (srfi srfi-35) #:export (managed-host-environment-type =20 @@ -304,6 +307,18 @@ of MACHINE's system profile, ordered from most recent = to oldest." (boot-parameters-kernel-arguments params)))))))) generations)))) =20 +(define-syntax-rule (with-roll-back should-roll-back? mbody ...) + "Catch exceptions that arise when binding MBODY, a monadic expression in +%STORE-MONAD, and collect their arguments in a &deploy-error condition, wi= th +the 'should-roll-back' field set to SHOULD-ROLL-BACK?" + (catch #t + (lambda () + mbody ...) + (lambda args + (raise (condition (&deploy-error + (should-roll-back should-roll-back?) + (captured-args args))))))) + (define (deploy-managed-host machine) "Internal implementation of 'deploy-machine' for MACHINE instances with = an environment type of 'managed-host." @@ -316,9 +331,62 @@ environment type of 'managed-host." (bootloader-configuration (operating-system-bootloader os)) (bootcfg (operating-system-bootcfg os menu-entries))) (mbegin %store-monad =2D (switch-to-system eval os) =2D (upgrade-shepherd-services eval os) =2D (install-bootloader eval bootloader-configuration bootcfg))))) + (with-roll-back #f + (switch-to-system eval os)) + (with-roll-back #t + (mbegin %store-monad + (upgrade-shepherd-services eval os) + (install-bootloader eval bootloader-configuration bootcfg)))))= )) + + +;;; +;;; Roll-back. +;;; + +(define (roll-back-managed-host machine) + "Internal implementation of 'roll-back-machine' for MACHINE instances wi= th +an environment type of 'managed-host." + (define remote-exp + (with-extensions (list guile-gcrypt) + (with-imported-modules (source-module-closure '((guix config) + (guix profiles))) + #~(begin + (use-modules (guix config) + (guix profiles)) + + (define %system-profile + (string-append %state-directory "/profiles/system")) + + (define target-generation + (relative-generation-spec->number %system-profile "-1")) + + (if target-generation + (switch-to-generation %system-profile target-generation) + 'error))))) + + (define roll-back-failure + (condition (&message (message (G_ "could not roll-back machine"))))) + + (mlet* %store-monad ((boot-parameters (machine-boot-parameters machine)) + (_ -> (if (< (length boot-parameters) 2) + (raise roll-back-failure))) + (entries -> (map boot-parameters->menu-entry + (list (second boot-parameters)))) + (old-entries -> (map boot-parameters->menu-entry + (drop boot-parameters 2))) + (bootloader -> (operating-system-bootloader + (machine-operating-system machine))) + (bootcfg (lower-object + ((bootloader-configuration-file-generator + (bootloader-configuration-bootloader + bootloader)) + bootloader entries + #:old-entries old-entries))) + (eval -> (cut machine-remote-eval machine <>)) + (remote-result (machine-remote-eval machine + remote-exp))) + (when (eqv? 'error remote-result) + (raise roll-back-failure)))) =20 ;;; @@ -329,6 +397,7 @@ environment type of 'managed-host." (environment-type (machine-remote-eval managed-host-remote-eval) (deploy-machine deploy-managed-host) + (roll-back-machine roll-back-managed-host) (name 'managed-host-environment-type) (description "Provisioning for machines that are accessible ove= r SSH and have a known host-name. This entails little more than maintaining an S= SH diff --git a/guix/remote.scm b/guix/remote.scm index 5fecd954e9..853029c54f 100644 =2D-- a/guix/remote.scm +++ b/guix/remote.scm @@ -24,6 +24,7 @@ #:use-module (guix monads) #:use-module (guix modules) #:use-module (guix derivations) + #:use-module (guix utils) #:use-module (ssh popen) #:use-module (srfi srfi-1) #:use-module (ice-9 match) diff --git a/guix/scripts/deploy.scm b/guix/scripts/deploy.scm index ebc99e52cc..d16e7d7480 100644 =2D-- a/guix/scripts/deploy.scm +++ b/guix/scripts/deploy.scm @@ -28,6 +28,8 @@ #:use-module (guix grafts) #:use-module (ice-9 format) #:use-module (srfi srfi-1) + #:use-module (srfi srfi-34) + #:use-module (srfi srfi-35) #:use-module (srfi srfi-37) #:export (guix-deploy)) =20 @@ -91,8 +93,19 @@ Perform the deployment specified by FILE.\n")) (with-store store (set-build-options-from-command-line store opts) (for-each (lambda (machine) =2D (info (G_ "deploying to ~a...") (machine-display-name = machine)) + (info (G_ "deploying to ~a...~%") + (machine-display-name machine)) (parameterize ((%current-system (assq-ref opts 'system)) (%graft? (assq-ref opts 'graft?))) =2D (run-with-store store (deploy-machine machine)))) + (guard (c ((message-condition? c) + (report-error (G_ "failed to deploy ~a: '~a= '~%") + (machine-display-name machine) + (condition-message c))) + ((deploy-error? c) + (when (deploy-error-should-roll-back c) + (info (G_ "rolling back ~a...~%") + (machine-display-name machine)) + (run-with-store store (roll-back-machine = machine))) + (apply throw (deploy-error-captured-args c)= ))) + (run-with-store store (deploy-machine machine))))) machines)))) =2D-=20 2.22.0 --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEa1VJLOiXAjQ2BGSm9Qb9Fp2P2VoFAl1LOyIACgkQ9Qb9Fp2P 2VoCvxAAppGfVYme2uuGk/NXKZP7h3ReraQACGxWwCHrg5oCI8azsR2hAO3+SbHG bvC96HLWy+87jh5TMmbjwr/QuJIrqwJ2zvX/54CyzCSUFaTVoJ66mqZiKGVUZt28 jehnD+TOUC8jp80ilobZm3PXXqeolQKb//AklEp/yaC6NxeLMtjceotl32w0jTEn iD9SiJGjgxcbnt8jue+hE5PpEy8f3PkCYcte0oHIutRl7T1AcuSx9xQOJso+MZ0Q igdZDRpYX8tsOLYhDxnVkWmWJhBVpXRxLFTo1JNSOrDOUc+sxZrH4PyfjN47iSfi +2Jl989AwLJxsV5ONBiVtKL7jWjkZBdTxHI3T0Ir6nVPyJJF704acKcLAnWkEj34 +vP0vLWYL7VpMLHdQkEdOxJKJBKBeu25181HdStPOvL7+MbdpYlp8sY39IRlhJ9e AdqyQ6YtzWC+1rRllYzM2j9rRwZhpqkjAicZe4q79ItgzpbKsKTCdN9L7LJXcdXp c6WwDKDmJEVzrij+cXizypzBEfD9+WYSobo04Q/B5bjMwe32HXgwvlBlm+kVyj0V ToirMKShNMQKZFRlAA92N913XpxGvCjmL02tDaQCzPEzCdRl0HS+jRe2xTvS7tC6 tjQxpCGBjvU419S6rWdeUG73zwcDTxbMWgEjsgsfLFMoUPo49x4= =68+q -----END PGP SIGNATURE----- --=-=-=--