1 ;;; GNU Guix --- Functional package management for GNU
2 ;;; Copyright © 2019 David Thompson <davet@gnu.org>
3 ;;; Copyright © 2019 Jakob L. Kreuze <zerodaysfordays@sdf.lonestar.org>
5 ;;; This file is part of GNU Guix.
7 ;;; GNU Guix is free software; you can redistribute it and/or modify it
8 ;;; under the terms of the GNU General Public License as published by
9 ;;; the Free Software Foundation; either version 3 of the License, or (at
10 ;;; your option) any later version.
12 ;;; GNU Guix is distributed in the hope that it will be useful, but
13 ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
14 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 ;;; GNU General Public License for more details.
17 ;;; You should have received a copy of the GNU General Public License
18 ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
20 (define-module (gnu machine)
21 #:use-module (gnu system)
22 #:use-module (guix derivations)
23 #:use-module (guix monads)
24 #:use-module (guix records)
25 #:use-module (guix store)
26 #:use-module ((guix utils) #:select (source-properties->location))
27 #:use-module (srfi srfi-35)
28 #:export (environment-type
31 environment-type-description
32 environment-type-location
38 machine-operating-system
49 deploy-error-should-roll-back
50 deploy-error-captured-args))
54 ;;; This module provides the types used to declare individual machines in a
55 ;;; heterogeneous Guix deployment. The interface allows users of specify system
56 ;;; configurations and the means by which resources should be provisioned on a
63 ;;; Declarations for resources that can be provisioned.
66 (define-record-type* <environment-type> environment-type
70 ;; Interface to the environment type's deployment code. Each procedure
71 ;; should take the same arguments as the top-level procedure of this file
72 ;; that shares the same name. For example, 'machine-remote-eval' should be
73 ;; of the form '(machine-remote-eval machine exp)'.
74 (machine-remote-eval environment-type-machine-remote-eval) ; procedure
75 (deploy-machine environment-type-deploy-machine) ; procedure
76 (roll-back-machine environment-type-roll-back-machine) ; procedure
79 (name environment-type-name) ; symbol
80 (description environment-type-description ; string
82 (location environment-type-location ; <location>
83 (default (and=> (current-source-location)
84 source-properties->location))
89 ;;; Declarations for machines in a deployment.
92 (define-record-type* <machine> machine
96 (operating-system machine-operating-system) ; <operating-system>
97 (environment machine-environment) ; symbol
98 (configuration machine-configuration ; configuration object
99 (default #f))) ; specific to environment
101 (define (machine-display-name machine)
102 "Return the host-name identifying MACHINE."
103 (operating-system-host-name (machine-operating-system machine)))
105 (define (machine-remote-eval machine exp)
106 "Evaluate EXP, a gexp, on MACHINE. Ensure that all the elements EXP refers to
107 are built and deployed to MACHINE beforehand."
108 (let ((environment (machine-environment machine)))
109 ((environment-type-machine-remote-eval environment) machine exp)))
111 (define (deploy-machine machine)
112 "Monadic procedure transferring the new system's OS closure to the remote
113 MACHINE, activating it on MACHINE and switching MACHINE to the new generation."
114 (let ((environment (machine-environment machine)))
115 ((environment-type-deploy-machine environment) machine)))
117 (define (roll-back-machine machine)
118 "Monadic procedure rolling back to the previous system generation on
119 MACHINE. Return the number of the generation that was current before switching
120 and the new generation number."
121 (let ((environment (machine-environment machine)))
122 ((environment-type-roll-back-machine environment) machine)))
129 (define-condition-type &deploy-error &error
131 (should-roll-back deploy-error-should-roll-back)
132 (captured-args deploy-error-captured-args))