guix-devel/guix/remote.scm

148 lines
6.0 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019 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 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 (srfi srfi-1)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-35)
#:use-module (ice-9 match)
#: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))
(raise (condition
(&message
(message (format #f (G_ "failed to run '~{~a~^ ~}'")
repl-command))))))
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)))))))