aboutsummaryrefslogtreecommitdiff
path: root/guix/remote.scm
blob: a58ec2103c3436fb32967847e0b86022cea37ae2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 (guix remote)
  #:use-module (guix ssh)
  #:use-module (guix gexp)
  #:use-module (guix i18n)
  #:use-module ((guix diagnostics) #:select (formatted-message))
  #:use-module (guix inferior)
  #:use-module (guix store)
  #:use-module (guix monads)
  #:use-module (guix modules)
  #:use-module (guix derivations)
  #:use-module (guix utils)
  #:use-module (ssh popen)
  #:use-module (ssh channel)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-35)
  #:export (remote-eval))

;;; Commentary:
;;;
;;; Note: This API is experimental and subject to change!
;;;
;;; Evaluate a gexp on a remote machine, over SSH, ensuring that all the
;;; elements the gexp refers to are deployed beforehand.  This is useful for
;;; expressions that have side effects; for pure expressions, you would rather
;;; build a derivation remotely or offload it.
;;;
;;; Code:

(define* (remote-pipe-for-gexp lowered session #:optional become-command)
  "Return a remote pipe for the given SESSION to evaluate LOWERED.  If
BECOME-COMMAND is given, use that to invoke the remote Guile REPL."
  (define shell-quote
    (compose object->string object->string))

  (define repl-command
    (append (or become-command '())
            (list
             (string-append (derivation-input-output-path
                             (lowered-gexp-guile lowered))
                            "/bin/guile")
             "--no-auto-compile")
            (append-map (lambda (directory)
                          `("-L" ,directory))
                        (lowered-gexp-load-path lowered))
            (append-map (lambda (directory)
                          `("-C" ,directory))
                        (lowered-gexp-load-path lowered))
            `("-c"
              ,(shell-quote (lowered-gexp-sexp lowered)))))

  (let ((pipe (apply open-remote-pipe* session OPEN_READ repl-command)))
    (when (eof-object? (peek-char pipe))
      (let ((status (channel-get-exit-status pipe)))
        (close-port pipe)
        (raise (formatted-message (G_ "remote command '~{~a~^ ~}' failed \
with status ~a")
                                  repl-command status))))
    pipe))

(define* (%remote-eval lowered session #:optional become-command)
  "Evaluate LOWERED, a lowered gexp, in SESSION.  This assumes that all the
prerequisites of EXP are already available on the host at SESSION.  If
BECOME-COMMAND is given, use that to invoke the remote Guile REPL."
  (let* ((pipe   (remote-pipe-for-gexp lowered session become-command))
         (result (read-repl-response pipe)))
    (close-port pipe)
    result))

(define (trampoline exp)
  "Return a \"trampoline\" gexp that evaluates EXP and writes the evaluation
result to the current output port using the (guix repl) protocol."
  (define program
    (program-file "remote-exp.scm" exp))

  (with-imported-modules (source-module-closure '((guix repl)))
    #~(begin
        (use-modules (guix repl))

        ;; We use CURRENT-OUTPUT-PORT for REPL messages, so redirect PROGRAM's
        ;; output to CURRENT-ERROR-PORT so that it does not interfere.
        (send-repl-response '(with-output-to-port (current-error-port)
                               (lambda ()
                                 (primitive-load #$program)))
                            (current-output-port))

        (force-output))))

(define* (remote-eval exp session
                      #:key
                      (build-locally? #t)
                      (system (%current-system))
                      (module-path %load-path)
                      (socket-name (%daemon-socket-uri))
                      (become-command #f))
  "Evaluate EXP, a gexp, on the host at SESSION, an SSH session.  Ensure that
all the elements EXP refers to are built and deployed to SESSION beforehand.
When BUILD-LOCALLY? is true, said dependencies are built locally and sent to
the remote store afterwards; otherwise, dependencies are built directly on the
remote store."
  (mlet* %store-monad ((lowered (lower-gexp (trampoline exp)
                                            #:system system
                                            #:guile-for-build #f
                                            #:module-path %load-path))
                       (remote -> (connect-to-remote-daemon session
                                                            socket-name)))
    (define inputs
      (cons (lowered-gexp-guile lowered)
            (lowered-gexp-inputs lowered)))

    (define sources
      (lowered-gexp-sources lowered))

    (if build-locally?
        (let ((to-send (append (append-map derivation-input-output-paths
                                           inputs)
                               sources)))
          (mbegin %store-monad
            (built-derivations inputs)
            ((store-lift send-files) to-send remote #:recursive? #t)
            (return (close-connection remote))
            (return (%remote-eval lowered session become-command))))
        (let ((to-send (append (map (compose derivation-file-name
                                             derivation-input-derivation)
                                    inputs)
                               sources)))
          (mbegin %store-monad
            ((store-lift send-files) to-send remote #:recursive? #t)
            (return (build-derivations remote inputs))
            (return (close-connection remote))
            (return (%remote-eval lowered session become-command)))))))