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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018, 2020 Mathieu Othacehe <m.othacehe@gmail.com>
;;; 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 (gnu installer utils)
#:use-module (guix utils)
#:use-module (guix build utils)
#:use-module (guix i18n)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-34)
#:use-module (ice-9 match)
#:use-module (ice-9 rdelim)
#:use-module (ice-9 regex)
#:use-module (ice-9 format)
#:use-module (ice-9 textual-ports)
#:export (read-lines
read-all
nearest-exact-integer
read-percentage
run-command
syslog-port
syslog
with-server-socket
current-server-socket
current-clients
send-to-clients))
(define* (read-lines #:optional (port (current-input-port)))
"Read lines from PORT and return them as a list."
(let loop ((line (read-line port))
(lines '()))
(if (eof-object? line)
(reverse lines)
(loop (read-line port)
(cons line lines)))))
(define (read-all file)
"Return the content of the given FILE as a string."
(call-with-input-file file
get-string-all))
(define (nearest-exact-integer x)
"Given a real number X, return the nearest exact integer, with ties going to
the nearest exact even integer."
(inexact->exact (round x)))
(define (read-percentage percentage)
"Read PERCENTAGE string and return the corresponding percentage as a
number. If no percentage is found, return #f"
(let ((result (string-match "^([0-9]+)%$" percentage)))
(and result
(string->number (match:substring result 1)))))
(define* (run-command command #:key locale)
"Run COMMAND, a list of strings, in the given LOCALE. Return true if
COMMAND exited successfully, #f otherwise."
(define env (environ))
(define (pause)
(format #t (G_ "Press Enter to continue.~%"))
(send-to-clients '(pause))
(environ env) ;restore environment variables
(match (select (cons (current-input-port) (current-clients))
'() '())
(((port _ ...) _ _)
(read-line port))))
(setenv "PATH" "/run/current-system/profile/bin")
(when locale
(let ((supported? (false-if-exception
(setlocale LC_ALL locale))))
;; If LOCALE is not supported, then set LANGUAGE, which might at
;; least give us translated messages.
(if supported?
(setenv "LC_ALL" locale)
(setenv "LANGUAGE"
(string-take locale
(or (string-index locale #\_)
(string-length locale)))))))
(guard (c ((invoke-error? c)
(newline)
(format (current-error-port)
(G_ "Command failed with exit code ~a.~%")
(invoke-error-exit-status c))
(syslog "command ~s failed with exit code ~a"
command (invoke-error-exit-status c))
(pause)
#f))
(syslog "running command ~s~%" command)
(apply invoke command)
(syslog "command ~s succeeded~%" command)
(newline)
(pause)
#t))
;;;
;;; Logging.
;;;
(define (open-syslog-port)
"Return an open port (a socket) to /dev/log or #f if that wasn't possible."
(let ((sock (socket AF_UNIX SOCK_DGRAM 0)))
(catch 'system-error
(lambda ()
(connect sock AF_UNIX "/dev/log")
(setvbuf sock 'line)
sock)
(lambda args
(close-port sock)
#f))))
(define syslog-port
(let ((port #f))
(lambda ()
"Return an output port to syslog."
(unless port
(set! port (open-syslog-port)))
(or port (%make-void-port "w")))))
(define-syntax syslog
(lambda (s)
"Like 'format', but write to syslog."
(syntax-case s ()
((_ fmt args ...)
(string? (syntax->datum #'fmt))
(with-syntax ((fmt (string-append "installer[~d]: "
(syntax->datum #'fmt))))
#'(format (syslog-port) fmt (getpid) args ...))))))
;;;
;;; Client protocol.
;;;
(define %client-socket-file
;; Unix-domain socket where the installer accepts connections.
"/var/guix/installer-socket")
(define current-server-socket
;; Socket on which the installer is currently accepting connections, or #f.
(make-parameter #f))
(define current-clients
;; List of currently connected clients.
(make-parameter '()))
(define* (open-server-socket
#:optional (socket-file %client-socket-file))
"Open SOCKET-FILE as a Unix-domain socket to accept incoming connections and
return it."
(mkdir-p (dirname socket-file))
(when (file-exists? socket-file)
(delete-file socket-file))
(let ((sock (socket AF_UNIX SOCK_STREAM 0)))
(bind sock AF_UNIX socket-file)
(listen sock 0)
sock))
(define (call-with-server-socket thunk)
(if (current-server-socket)
(thunk)
(let ((socket (open-server-socket)))
(dynamic-wind
(const #t)
(lambda ()
(parameterize ((current-server-socket socket))
(thunk)))
(lambda ()
(close-port socket))))))
(define-syntax-rule (with-server-socket exp ...)
"Evaluate EXP with 'current-server-socket' parameterized to a currently
accepting socket."
(call-with-server-socket (lambda () exp ...)))
(define* (send-to-clients exp)
"Send EXP to all the current clients."
(define remainder
(fold (lambda (client remainder)
(catch 'system-error
(lambda ()
(write exp client)
(newline client)
(force-output client)
(cons client remainder))
(lambda args
;; We might get EPIPE if the client disconnects; when that
;; happens, remove CLIENT from the set of available clients.
(let ((errno (system-error-errno args)))
(if (memv errno (list EPIPE ECONNRESET ECONNABORTED))
(begin
(syslog "removing client ~s due to ~s while replying~%"
(fileno client) (strerror errno))
(false-if-exception (close-port client))
remainder)
(cons client remainder))))))
'()
(current-clients)))
(current-clients (reverse remainder))
exp)