From patchwork Mon Jul 29 22:37:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jakob L. Kreuze" X-Patchwork-Id: 14788 Return-Path: X-Original-To: patchwork@mira.cbaines.net Delivered-To: patchwork@mira.cbaines.net Received: by mira.cbaines.net (Postfix, from userid 113) id 301AB1728C; Mon, 29 Jul 2019 23:41:13 +0100 (BST) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on mira.cbaines.net X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mira.cbaines.net (Postfix) with ESMTP id B26EB1728A for ; Mon, 29 Jul 2019 23:41:12 +0100 (BST) Received: from localhost ([::1]:56830 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hsEKO-000550-De for patchwork@mira.cbaines.net; Mon, 29 Jul 2019 18:41:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42569) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hsEKG-00050X-7f for guix-patches@gnu.org; Mon, 29 Jul 2019 18:41:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hsEKE-0006jO-Gm for guix-patches@gnu.org; Mon, 29 Jul 2019 18:41:04 -0400 Received: from debbugs.gnu.org ([209.51.188.43]:40457) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hsEKE-0006jK-CU for guix-patches@gnu.org; Mon, 29 Jul 2019 18:41:02 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1hsEKE-0000IM-9j for guix-patches@gnu.org; Mon, 29 Jul 2019 18:41:02 -0400 X-Loop: help-debbugs@gnu.org Subject: [bug#36845] [PATCH] machine: Implement 'roll-back-machine'. Resent-From: zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) Original-Sender: "Debbugs-submit" Resent-CC: guix-patches@gnu.org Resent-Date: Mon, 29 Jul 2019 22:41:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: report 36845 X-GNU-PR-Package: guix-patches X-GNU-PR-Keywords: patch To: 36845@debbugs.gnu.org X-Debbugs-Original-To: guix-patches@gnu.org Received: via spool by submit@debbugs.gnu.org id=B.15644400131040 (code B ref -1); Mon, 29 Jul 2019 22:41:02 +0000 Received: (at submit) by debbugs.gnu.org; 29 Jul 2019 22:40:13 +0000 Received: from localhost ([127.0.0.1]:49273 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hsEJO-0000Ga-G7 for submit@debbugs.gnu.org; Mon, 29 Jul 2019 18:40:10 -0400 Received: from lists.gnu.org ([209.51.188.17]:56095) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hsEJM-0000GT-Jy for submit@debbugs.gnu.org; Mon, 29 Jul 2019 18:40:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42415) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hsEJK-0004ek-UM for guix-patches@gnu.org; Mon, 29 Jul 2019 18:40:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hsEJJ-00060L-B2 for guix-patches@gnu.org; Mon, 29 Jul 2019 18:40:06 -0400 Received: from mx.sdf.org ([205.166.94.20]:51420) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hsEJI-000601-VH for guix-patches@gnu.org; Mon, 29 Jul 2019 18:40:05 -0400 Received: from Epsilon (pool-173-76-53-40.bstnma.fios.verizon.net [173.76.53.40]) (authenticated (0 bits)) by mx.sdf.org (8.15.2/8.14.5) with ESMTPSA id x6TMe2kL026764 (using TLSv1.2 with cipher AES256-GCM-SHA384 (256 bits) verified NO) for ; Mon, 29 Jul 2019 22:40:03 GMT From: zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) Date: Mon, 29 Jul 2019 18:37:14 -0400 Message-ID: <87pnlsii1x.fsf@sdf.lonestar.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 X-BeenThere: guix-patches@gnu.org List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-patches-bounces+patchwork=mira.cbaines.net@gnu.org Sender: "Guix-patches" X-getmail-retrieved-from-mailbox: Patches * 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. --- 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 0b79402b0a..a143fd190a 100644 --- 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 deploy-machine - machine-remote-eval)) + roll-back-machine + machine-remote-eval + + &deploy-error + deploy-error? + deploy-error-should-roll-back + deploy-error-captured-args)) ;;; 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 ;; 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 generation." (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 switching +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 552eafa9de..b96e71ddce 100644 --- a/gnu/machine/ssh.scm +++ b/gnu/machine/ssh.scm @@ -17,6 +17,7 @@ ;;; along with GNU Guix. If not, see . (define-module (gnu machine ssh) + #:use-module (gnu bootloader) #:use-module (gnu machine) #:autoload (gnu packages gnupg) (guile-gcrypt) #:use-module (gnu system) @@ -30,8 +31,10 @@ #:use-module (guix ssh) #:use-module (guix store) #: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 @@ -161,6 +164,18 @@ of MACHINE's system profile, ordered from most recent to oldest." (boot-parameters-kernel-arguments params)))))))) generations)))) +(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, with +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." @@ -172,9 +187,62 @@ environment type of 'managed-host." (bootloader-configuration (operating-system-bootloader os)) (bootcfg (operating-system-bootcfg os menu-entries))) (mbegin %store-monad - (switch-to-system eval os) - (upgrade-shepherd-services eval os) - (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 with +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)))) ;;; @@ -185,6 +253,7 @@ 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 over SSH and have a known host-name. This entails little more than maintaining an SSH diff --git a/guix/remote.scm b/guix/remote.scm index 5fecd954e9..853029c54f 100644 --- 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 52bba3f3bf..8eeb9ae7a1 100644 --- a/guix/scripts/deploy.scm +++ b/guix/scripts/deploy.scm @@ -27,6 +27,8 @@ #: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)) @@ -87,8 +89,19 @@ Perform the deployment specified by FILE.\n")) (with-store store (set-build-options-from-command-line store opts) (for-each (lambda (machine) - (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?))) - (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))))