1 ;;; GNU Guix --- Functional package management for GNU
2 ;;; Copyright © 2019 David Thompson <davet@gnu.org>
3 ;;; Copyright © 2019 Jakob L. Kreuze <zerodaysfordays@sdf.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
37 machine-operating-system
48 deploy-error-should-roll-back
49 deploy-error-captured-args))
53 ;;; This module provides the types used to declare individual machines in a
54 ;;; heterogeneous Guix deployment. The interface allows users of specify system
55 ;;; configurations and the means by which resources should be provisioned on a
62 ;;; Declarations for resources that can be provisioned.
65 (define-record-type* <environment-type> environment-type
69 ;; Interface to the environment type's deployment code. Each procedure
70 ;; should take the same arguments as the top-level procedure of this file
71 ;; that shares the same name. For example, 'machine-remote-eval' should be
72 ;; of the form '(machine-remote-eval machine exp)'.
73 (machine-remote-eval environment-type-machine-remote-eval) ; procedure
74 (deploy-machine environment-type-deploy-machine) ; procedure
75 (roll-back-machine environment-type-roll-back-machine) ; procedure
78 (name environment-type-name) ; symbol
79 (description environment-type-description ; string
81 (location environment-type-location ; <location>
82 (default (and=> (current-source-location)
83 source-properties->location))
88 ;;; Declarations for machines in a deployment.
91 (define-record-type* <machine> machine make-machine
93 (operating-system %machine-operating-system); <operating-system>
94 (environment machine-environment) ; symbol
95 (configuration machine-configuration ; configuration object
96 (default #f))) ; specific to environment
98 (define (machine-operating-system machine)
99 "Return the operating system of MACHINE."
100 (operating-system-with-provenance
101 (%machine-operating-system machine)))
103 (define (machine-display-name machine)
104 "Return the host-name identifying MACHINE."
105 (operating-system-host-name (machine-operating-system machine)))
107 (define (machine-remote-eval machine exp)
108 "Evaluate EXP, a gexp, on MACHINE. Ensure that all the elements EXP refers to
109 are built and deployed to MACHINE beforehand."
110 (let ((environment (machine-environment machine)))
111 ((environment-type-machine-remote-eval environment) machine exp)))
113 (define (deploy-machine machine)
114 "Monadic procedure transferring the new system's OS closure to the remote
115 MACHINE, activating it on MACHINE and switching MACHINE to the new generation."
116 (let ((environment (machine-environment machine)))
117 ((environment-type-deploy-machine environment) machine)))
119 (define (roll-back-machine machine)
120 "Monadic procedure rolling back to the previous system generation on
121 MACHINE. Return the number of the generation that was current before switching
122 and the new generation number."
123 (let ((environment (machine-environment machine)))
124 ((environment-type-roll-back-machine environment) machine)))
131 (define-condition-type &deploy-error &error
133 (should-roll-back deploy-error-should-roll-back)
134 (captured-args deploy-error-captured-args))