From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:470:142:3::10]:34699) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyAml-0000sq-VS for guix-patches@gnu.org; Thu, 15 Aug 2019 04:07:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hyAmk-0004ij-3P for guix-patches@gnu.org; Thu, 15 Aug 2019 04:07:03 -0400 Received: from debbugs.gnu.org ([209.51.188.43]:41754) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hyAmj-0004ic-Vm for guix-patches@gnu.org; Thu, 15 Aug 2019 04:07:02 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1hyAmj-0004ZF-Ov for guix-patches@gnu.org; Thu, 15 Aug 2019 04:07:01 -0400 Subject: [bug#36957] [PATCH 2/5] machine: Implement 'roll-back-machine'. Resent-Message-ID: From: zerodaysfordays@sdf.lonestar.org (Jakob L. Kreuze) References: <87a7cl3zyy.fsf@sdf.lonestar.org> <87sgqcobds.fsf@dustycloud.org> <87pnlgjymv.fsf_-_@sdf.lonestar.org> <87y304vyyo.fsf@elephly.net> <87tvarjtgw.fsf@sdf.lonestar.org> <87h86jxyea.fsf@dustycloud.org> <875zmy26u6.fsf_-_@sdf.lonestar.org> <871rxm26rz.fsf_-_@sdf.lonestar.org> Date: Thu, 15 Aug 2019 04:05:57 -0400 In-Reply-To: <871rxm26rz.fsf_-_@sdf.lonestar.org> (Jakob L. Kreuze's message of "Thu, 15 Aug 2019 04:05:04 -0400") Message-ID: <87wofezwd6.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: 36957@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 | 72 +++++++++++++++++++++++++++++++++++++++-- guix/scripts/deploy.scm | 17 ++++++++-- 3 files changed, 110 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 fb15d39e61..4b5d5fe3a2 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) @@ -34,6 +35,7 @@ #: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) @@ -341,6 +343,18 @@ 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." @@ -353,9 +367,60 @@ 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 %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))) + (remote-result (machine-remote-eval machine remote-= exp))) + (when (eqv? 'error remote-result) + (raise roll-back-failure)))) =20 ;;; @@ -366,6 +431,7 @@ 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/scripts/deploy.scm b/guix/scripts/deploy.scm index 81f2b33260..6a67985c8b 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 @@ -88,7 +90,18 @@ 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 ((%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----- iQIzBAEBCAAdFiEEa1VJLOiXAjQ2BGSm9Qb9Fp2P2VoFAl1VEmUACgkQ9Qb9Fp2P 2VoumRAApeAaUtssPZi4IrSnzW3YS6f/Erp9jZBDzfOcRjG2RUtZNgARQ8+vitNH iDIZynwsSR2MxX203/fBG6OuKgMvBzME9nQKGV49+2eWE+8GBroHl19SNT3j0avm 0zU1q4rbxEMCaMkkMyzb2WoZ8iJlUlitOyJFh0TO59XWSgt4HyRWD8/HsfIcT+vo 3TqqnZUVQh50a7V6/+i0GqtuuPWTHkyRiuPO/l0xFBonM0/XRBO4xucM3As0BJ9O kogC78e7Jxk94TGmGFxN/Ob0KUZw1lw+JqKvw0lZyhBxAy+jYnT98dmUqxJmzrOz JPrnNYDlnRj/FZqGwk28/3ypcR60UE59gLxeYuCYpj9t8aCeQbZsRW0tI19qMu76 aK1Wbb767ku0OVOSOk0U1/Um8yosdF7O7DFyFIke7NJKQnlOnsoYmuswYIrE+BgM LpHOPxVF59kFa9jJ85px7L1sTpHdVV1J8fj7L0dr6SO9WWXPcjThUJjsUJxzD4RF peOVqOtxybpkGuIZQxzSkjR1LXyopd9hA8oIZ2oucSMoahvV9y7pE7gwKONqzYm5 3j0azC1wfPmyJfUvM4PrkLNKd8mua7PexBvrspvPymmGFzzjjRcCmjkT+j6EBtY2 QAZKwjiodu4AO0eg67PzcUpPB8PYrIqHWLgJv9DEI2XkbMvwJ9k= =jkYl -----END PGP SIGNATURE----- --=-=-=--