gnu/machine.scm

   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   #:export (environment-type
  28             environment-type?
  29             environment-type-name
  30             environment-type-description
  31             environment-type-location
  32
  33             machine
  34             machine?
  35             this-machine
  36
  37             machine-system
  38             machine-environment
  39             machine-configuration
  40             machine-display-name
  41
  42             deploy-machine
  43             machine-remote-eval))
  44
  45 ;;; Commentary:
  46 ;;;
  47 ;;; This module provides the types used to declare individual machines in a
  48 ;;; heterogeneous Guix deployment. The interface allows users of specify system
  49 ;;; configurations and the means by which resources should be provisioned on a
  50 ;;; per-host basis.
  51 ;;;
  52 ;;; Code:
  53
  54 \f
  55 ;;;
  56 ;;; Declarations for resources that can be provisioned.
  57 ;;;
  58
  59 (define-record-type* <environment-type> environment-type
  60   make-environment-type
  61   environment-type?
  62
  63   ;; Interface to the environment type's deployment code. Each procedure
  64   ;; should take the same arguments as the top-level procedure of this file
  65   ;; that shares the same name. For example, 'machine-remote-eval' should be
  66   ;; of the form '(machine-remote-eval machine exp)'.
  67   (machine-remote-eval environment-type-machine-remote-eval) ; procedure
  68   (deploy-machine      environment-type-deploy-machine)      ; procedure
  69
  70   ;; Metadata.
  71   (name        environment-type-name)       ; symbol
  72   (description environment-type-description ; string
  73                (default #f))
  74   (location    environment-type-location    ; <location>
  75                (default (and=> (current-source-location)
  76                                source-properties->location))
  77                (innate)))
  78
  79 \f
  80 ;;;
  81 ;;; Declarations for machines in a deployment.
  82 ;;;
  83
  84 (define-record-type* <machine> machine
  85   make-machine
  86   machine?
  87   this-machine
  88   (system        machine-system)       ; <operating-system>
  89   (environment   machine-environment)  ; symbol
  90   (configuration machine-configuration ; configuration object
  91                  (default #f)))        ; specific to environment
  92
  93 (define (machine-display-name machine)
  94   "Return the host-name identifying MACHINE."
  95   (operating-system-host-name (machine-system machine)))
  96
  97 (define (machine-remote-eval machine exp)
  98   "Evaluate EXP, a gexp, on MACHINE. Ensure that all the elements EXP refers to
  99 are built and deployed to MACHINE beforehand."
 100   (let ((environment (machine-environment machine)))
 101     ((environment-type-machine-remote-eval environment) machine exp)))
 102
 103 (define (deploy-machine machine)
 104   "Monadic procedure transferring the new system's OS closure to the remote
 105 MACHINE, activating it on MACHINE and switching MACHINE to the new generation."
 106   (let ((environment (machine-environment machine)))
 107     ((environment-type-deploy-machine environment) machine)))