;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019 Jakob L. Kreuze <zerodaysfordays@sdf.org>
;;; Copyright © 2024 Herman Rimm <herman@rimm.ee>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu tests deploy)
  #:use-module (gnu packages gnupg)
  #:use-module ((guix self) #:select (make-config.scm))
  #:use-module (gnu services)
  #:use-module (gnu services base)
  #:use-module (gnu services ssh)
  #:use-module (gnu system)
  #:use-module (gnu system vm)
  #:use-module (gnu tests)
  #:use-module (guix gexp)
  #:use-module (guix modules)
  #:use-module (ice-9 match)
  #:export (%test-deploy
            %test-rollback))

;;; Commentary:
;;;
;;; Test in-place system deployment: advancing the system generation on
;;; a running instance of the Guix System.
;;;
;;; Code:

(define (machines os)
  (program-file "machines.scm"
    #~(list (machine (configuration
                      (machine-ssh-configuration
                        (host-name "localhost")
                        (system (%current-system))))
                     (environment managed-host-environment-type)
                     (operating-system #$os)))))

(define not-config?
  ;; Select (guix …) and (gnu …) modules, except (guix config).
  (match-lambda
    (('guix 'config) #f)
    (('guix rest ...) #t)
    (('gnu rest ...) #t)
    (_ #f)))

(define* (deploy-program #:optional (os #~%simple-os))
  (program-file "deploy.scm"
    (with-extensions (list guile-gcrypt)
      (with-imported-modules `(,@(source-module-closure
                                  '((guix scripts deploy))
                                  #:select? not-config?)
                               ((guix config) => ,(make-config.scm)))
        #~(begin
            (use-modules (guix scripts deploy))
            (guix-deploy #$(machines os)))))))

(define os
  (marionette-operating-system
    (simple-operating-system
      (service openssh-service-type
        (openssh-configuration
          (permit-root-login #t)
          (allow-empty-passwords? #t)))
      (service static-networking-service-type
        (list (static-networking
                (inherit %loopback-static-networking)
                (provision '(networking))))))
    #:imported-modules '((gnu services herd)
                         (guix combinators))))

(define vm (virtual-machine os))

(define* (run-deploy-test)
  "Run a test of an OS running DEPLOY-PROGRAM, which creates a new
generation of the system profile."
  (define (test script)
    (with-imported-modules '((gnu build marionette))
      #~(begin
          (use-modules (gnu build marionette)
                       (srfi srfi-64))

          (define marionette
            (make-marionette (list #$vm)))

          ;; Return the names of the generation symlinks on MARIONETTE.
          (define (system-generations marionette)
            (marionette-eval
             '(begin
                (use-modules (ice-9 ftw)
                             (srfi srfi-1))
                (let* ((profile-dir "/var/guix/profiles/")
                       (entries (map first (cddr (file-system-tree profile-dir)))))
                  (remove (lambda (entry)
                            (member entry '("per-user" "system")))
                          entries)))
             marionette))

          (test-runner-current (system-test-runner #$output))
          (test-begin "deploy")

          (let ((generations-prior (system-generations marionette)))
            (test-assert "script successfully evaluated"
              (marionette-eval
               '(primitive-load #$script)
               marionette))

            (test-equal "script created new generation"
              (length (system-generations marionette))
              (1+ (length generations-prior)))

            (test-equal "script activated the new generation"
              (string-append "/var/guix/profiles/system-"
                             (number->string (+ 1 (length generations-prior)))
                             "-link")
              (marionette-eval '(readlink "/run/current-system")
                               marionette)))

          (test-end))))

  (gexp->derivation "deploy" (test (deploy-program))))

(define* (run-rollback-test)
  "Run a test of an OS with a faulty bootloader running DEPLOY-PROGRAM,
which causes a rollback."
  (define os
    #~(operating-system
        (inherit %simple-os)
        (bootloader
         (bootloader-configuration
           (inherit (operating-system-bootloader
                      %simple-os))
           (targets '("/dev/null"))))))

  (define (test script)
    (with-imported-modules '((gnu build marionette))
      #~(begin
          (use-modules (gnu build marionette)
                       (srfi srfi-64))

          (define marionette
            (make-marionette (list #$vm)))

          ;; Return the names of the generation symlinks on MARIONETTE.
          (define (system-generations marionette)
            (marionette-eval
             '(begin
                (use-modules (ice-9 ftw)
                             (srfi srfi-1))
                (let* ((profile-dir "/var/guix/profiles/")
                       (entries (map first (cddr (file-system-tree profile-dir)))))
                  (remove (lambda (entry)
                            (member entry '("per-user" "system")))
                          entries)))
             marionette))

          (test-runner-current (system-test-runner #$output))
          (test-begin "rollback")

          (let ((generations-prior (system-generations marionette)))
            (test-assert "script successfully evaluated"
              (marionette-eval
               '(primitive-load #$script)
               marionette))

            (test-equal "script created new generation"
              (length (system-generations marionette))
              (1+ (length generations-prior)))

            (test-equal "script rolled back the new generation"
              (string-append "/var/guix/profiles/system-"
                             (number->string (length generations-prior))
                             "-link")
              (marionette-eval '(readlink "/run/current-system")
                               marionette)))

          (test-end))))

  (gexp->derivation "rollback" (test (deploy-program os))))

(define %test-deploy
  (system-test
   (name "deploy")
   (description "Deploy to the local machine.")
   (value (run-deploy-test))))

(define %test-rollback
  (system-test
   (name "rollback")
   (description "Rollback the deployment of a faulty bootloader.")
   (value (run-rollback-test))))