| 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> |
| 4 | ;;; |
| 5 | ;;; This file is part of GNU Guix. |
| 6 | ;;; |
| 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. |
| 11 | ;;; |
| 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. |
| 16 | ;;; |
| 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/>. |
| 19 | |
| 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 |
| 29 | environment-type? |
| 30 | environment-type-name |
| 31 | environment-type-description |
| 32 | environment-type-location |
| 33 | |
| 34 | machine |
| 35 | machine? |
| 36 | |
| 37 | machine-operating-system |
| 38 | machine-environment |
| 39 | machine-configuration |
| 40 | machine-display-name |
| 41 | |
| 42 | deploy-machine |
| 43 | roll-back-machine |
| 44 | machine-remote-eval |
| 45 | |
| 46 | &deploy-error |
| 47 | deploy-error? |
| 48 | deploy-error-should-roll-back |
| 49 | deploy-error-captured-args)) |
| 50 | |
| 51 | ;;; Commentary: |
| 52 | ;;; |
| 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 |
| 56 | ;;; per-host basis. |
| 57 | ;;; |
| 58 | ;;; Code: |
| 59 | |
| 60 | \f |
| 61 | ;;; |
| 62 | ;;; Declarations for resources that can be provisioned. |
| 63 | ;;; |
| 64 | |
| 65 | (define-record-type* <environment-type> environment-type |
| 66 | make-environment-type |
| 67 | environment-type? |
| 68 | |
| 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 |
| 76 | |
| 77 | ;; Metadata. |
| 78 | (name environment-type-name) ; symbol |
| 79 | (description environment-type-description ; string |
| 80 | (default #f)) |
| 81 | (location environment-type-location ; <location> |
| 82 | (default (and=> (current-source-location) |
| 83 | source-properties->location)) |
| 84 | (innate))) |
| 85 | |
| 86 | \f |
| 87 | ;;; |
| 88 | ;;; Declarations for machines in a deployment. |
| 89 | ;;; |
| 90 | |
| 91 | (define-record-type* <machine> machine make-machine |
| 92 | 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 |
| 97 | |
| 98 | (define (machine-operating-system machine) |
| 99 | "Return the operating system of MACHINE." |
| 100 | (operating-system-with-provenance |
| 101 | (%machine-operating-system machine))) |
| 102 | |
| 103 | (define (machine-display-name machine) |
| 104 | "Return the host-name identifying MACHINE." |
| 105 | (operating-system-host-name (machine-operating-system machine))) |
| 106 | |
| 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))) |
| 112 | |
| 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))) |
| 118 | |
| 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))) |
| 125 | |
| 126 | \f |
| 127 | ;;; |
| 128 | ;;; Error types. |
| 129 | ;;; |
| 130 | |
| 131 | (define-condition-type &deploy-error &error |
| 132 | deploy-error? |
| 133 | (should-roll-back deploy-error-should-roll-back) |
| 134 | (captured-args deploy-error-captured-args)) |