guix-devel/guix/scripts/container/exec.scm

106 lines
4.0 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 David Thompson <davet@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 scripts container exec)
#:use-module (ice-9 match)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-37)
#:use-module (guix scripts)
#:use-module (guix ui)
#:use-module (guix utils)
#:use-module (gnu build linux-container)
#:export (guix-container-exec))
(define %options
(list (option '(#\h "help") #f #f
(lambda args
(show-help)
(exit 0)))
(option '(#\V "version") #f #f
(lambda args
(show-version-and-exit "guix container exec")))))
(define (show-help)
(display (_ "Usage: guix container exec PID COMMAND [ARGS...]
Execute COMMMAND within the container process PID.\n"))
(newline)
(display (_ "
-h, --help display this help and exit"))
(display (_ "
-V, --version display version information and exit"))
(newline)
(show-bug-report-information))
(define (partition-args args)
"Split ARGS into two lists; one containing the arguments for this program,
and the other containing arguments for the command to be executed."
(define (number-string? str)
(false-if-exception (string->number str)))
(let loop ((a '())
(b args))
(match b
(()
(values (reverse a) '()))
(((? number-string? head) . tail)
(values (reverse (cons head a)) tail))
((head . tail)
(loop (cons head a) tail)))))
(define (guix-container-exec . args)
(define (handle-argument arg result)
(if (assoc-ref result 'pid)
(leave (_ "~a: extraneous argument~%") arg)
(alist-cons 'pid (string->number* arg) result)))
(with-error-handling
(let-values (((args command) (partition-args args)))
(let* ((opts (parse-command-line args %options '(())
#:argument-handler
handle-argument))
(pid (assoc-ref opts 'pid))
(environment (filter-map (lambda (name)
(let ((value (getenv name)))
(and value (cons name value))))
;; Pass through the TERM environment
;; variable to inform processes about
;; the capabilities of the terminal.
'("TERM"))))
(unless pid
(leave (_ "no pid specified~%")))
(when (null? command)
(leave (_ "no command specified~%")))
(unless (file-exists? (string-append "/proc/" (number->string pid)))
(leave (_ "no such process ~d~%") pid))
(let ((result (container-excursion pid
(lambda ()
(match command
((program . program-args)
(for-each (match-lambda
((name . value)
(setenv name value)))
environment)
(apply execlp program program program-args)))))))
(unless (zero? result)
(leave (_ "exec failed with status ~d~%") result)))))))