guix-devel/guix/remote.scm

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;;; 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 inferior)
#:use-module (guix store)
#:use-module (guix monads)
#:use-module (guix modules)
#:use-module (guix derivations)
#:use-module (ssh popen)
#:use-module (srfi srfi-1)
#: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)
"Return a remote pipe for the given SESSION to evaluate LOWERED."
(define shell-quote
(compose object->string object->string))
(apply open-remote-pipe* session OPEN_READ
(string-append (derivation-input-output-path
(lowered-gexp-guile lowered))
"/bin/guile")
"--no-auto-compile"
(append (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))))))
(define (%remote-eval lowered session)
"Evaluate LOWERED, a lowered gexp, in SESSION. This assumes that all the
prerequisites of EXP are already available on the host at SESSION."
(let* ((pipe (remote-pipe-for-gexp lowered session))
(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
(scheme-file "remote-exp.scm" exp))
(with-imported-modules (source-module-closure '((guix repl)))
#~(begin
(use-modules (guix repl))
(send-repl-response '(primitive-load #$program)
(current-output-port))
(force-output))))
(define* (remote-eval exp session
#:key
(build-locally? #t)
(module-path %load-path)
(socket-name "/var/guix/daemon-socket/socket"))
"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)
#: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))))
(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)))))))