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* gnu/installer/utils.scm (run-external-command-with-handler, run-external-command-with-line-hooks): New variables. (run-command): Use run-external-command-with-line-hooks. Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
335 lines
11 KiB
Scheme
335 lines
11 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
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;;; Copyright © 2018, 2020 Mathieu Othacehe <m.othacehe@gmail.com>
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;;; Copyright © 2019, 2020 Ludovic Courtès <ludo@gnu.org>
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;;;
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;;; This file is part of GNU Guix.
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;;;
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;;; GNU Guix is free software; you can redistribute it and/or modify it
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;;; under the terms of the GNU General Public License as published by
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;;; the Free Software Foundation; either version 3 of the License, or (at
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;;; your option) any later version.
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;;;
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;;; GNU Guix is distributed in the hope that it will be useful, but
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;;; WITHOUT ANY WARRANTY; without even the implied warranty of
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;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;;; GNU General Public License for more details.
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;;;
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;;; You should have received a copy of the GNU General Public License
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;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
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(define-module (gnu installer utils)
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#:use-module (gnu services herd)
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#:use-module (guix utils)
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#:use-module (guix build utils)
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#:use-module (guix i18n)
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#:use-module (srfi srfi-1)
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#:use-module (srfi srfi-19)
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#:use-module (srfi srfi-34)
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#:use-module (ice-9 control)
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#:use-module (ice-9 match)
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#:use-module (ice-9 popen)
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#:use-module (ice-9 rdelim)
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#:use-module (ice-9 regex)
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#:use-module (ice-9 format)
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#:use-module (ice-9 textual-ports)
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#:export (read-lines
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read-all
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nearest-exact-integer
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read-percentage
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run-external-command-with-handler
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run-external-command-with-line-hooks
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run-command
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syslog-port
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%syslog-line-hook
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installer-log-port
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%installer-log-line-hook
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%default-installer-line-hooks
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installer-log-line
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call-with-time
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let/time
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with-server-socket
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current-server-socket
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current-clients
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send-to-clients
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with-silent-shepherd))
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(define* (read-lines #:optional (port (current-input-port)))
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"Read lines from PORT and return them as a list."
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(let loop ((line (read-line port))
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(lines '()))
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(if (eof-object? line)
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(reverse lines)
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(loop (read-line port)
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(cons line lines)))))
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(define (read-all file)
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"Return the content of the given FILE as a string."
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(call-with-input-file file
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get-string-all))
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(define (nearest-exact-integer x)
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"Given a real number X, return the nearest exact integer, with ties going to
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the nearest exact even integer."
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(inexact->exact (round x)))
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(define (read-percentage percentage)
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"Read PERCENTAGE string and return the corresponding percentage as a
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number. If no percentage is found, return #f"
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(let ((result (string-match "^([0-9]+)%$" percentage)))
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(and result
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(string->number (match:substring result 1)))))
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(define* (run-external-command-with-handler handler command)
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"Run command specified by the list COMMAND in a child with output handler
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HANDLER. HANDLER is a procedure taking an input port, to which the command
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will write its standard output and error. Returns the integer status value of
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the child process as returned by waitpid."
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(match-let (((input . output) (pipe)))
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;; Hack to work around Guile bug 52835
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(define dup-output (duplicate-port output "w"))
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;; Void pipe, but holds the pid for close-pipe.
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(define dummy-pipe
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(with-input-from-file "/dev/null"
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(lambda ()
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(with-output-to-port output
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(lambda ()
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(with-error-to-port dup-output
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(lambda ()
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(apply open-pipe* (cons "" command)))))))))
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(close-port output)
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(close-port dup-output)
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(handler input)
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(close-port input)
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(close-pipe dummy-pipe)))
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(define (run-external-command-with-line-hooks line-hooks command)
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"Run command specified by the list COMMAND in a child, processing each
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output line with the procedures in LINE-HOOKS. Returns the integer status
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value of the child process as returned by waitpid."
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(define (handler input)
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(and
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(and=> (get-line input)
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(lambda (line)
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(if (eof-object? line)
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#f
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(begin (for-each (lambda (f) (f line))
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(append line-hooks
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%default-installer-line-hooks))
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#t))))
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(handler input)))
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(run-external-command-with-handler handler command))
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(define* (run-command command)
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"Run COMMAND, a list of strings. Return true if COMMAND exited
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successfully, #f otherwise."
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(define (pause)
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(format #t (G_ "Press Enter to continue.~%"))
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(send-to-clients '(pause))
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(match (select (cons (current-input-port) (current-clients))
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'() '())
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(((port _ ...) _ _)
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(read-line port))))
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(installer-log-line "running command ~s" command)
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(define result (run-external-command-with-line-hooks
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(list %display-line-hook)
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command))
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(define exit-val (status:exit-val result))
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(define term-sig (status:term-sig result))
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(define stop-sig (status:stop-sig result))
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(define succeeded?
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(cond
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((and exit-val (not (zero? exit-val)))
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(installer-log-line "command ~s exited with value ~a"
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command exit-val)
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(format #t (G_ "Command ~s exited with value ~a")
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command exit-val)
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#f)
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(term-sig
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(installer-log-line "command ~s killed by signal ~a"
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command term-sig)
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(format #t (G_ "Command ~s killed by signal ~a")
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command term-sig)
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#f)
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(stop-sig
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(installer-log-line "command ~s stopped by signal ~a"
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command stop-sig)
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(format #t (G_ "Command ~s stopped by signal ~a")
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command stop-sig)
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#f)
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(else
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(installer-log-line "command ~s succeeded" command)
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(format #t (G_ "Command ~s succeeded") command)
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#t)))
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(newline)
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(pause)
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succeeded?)
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;;;
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;;; Logging.
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;;;
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(define (call-with-time thunk kont)
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"Call THUNK and pass KONT the elapsed time followed by THUNK's return
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values."
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(let* ((start (current-time time-monotonic))
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(result (call-with-values thunk list))
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(end (current-time time-monotonic)))
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(apply kont (time-difference end start) result)))
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(define-syntax-rule (let/time ((time result exp)) body ...)
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(call-with-time (lambda () exp) (lambda (time result) body ...)))
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(define (open-syslog-port)
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"Return an open port (a socket) to /dev/log or #f if that wasn't possible."
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(let ((sock (socket AF_UNIX SOCK_DGRAM 0)))
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(catch 'system-error
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(lambda ()
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(connect sock AF_UNIX "/dev/log")
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(setvbuf sock 'line)
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sock)
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(lambda args
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(close-port sock)
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#f))))
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(define syslog-port
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(let ((port #f))
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(lambda ()
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"Return an output port to syslog."
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(unless port
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(set! port (open-syslog-port)))
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(or port (%make-void-port "w")))))
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(define (%syslog-line-hook line)
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(format (syslog-port) "installer[~d]: ~a~%" (getpid) line))
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(define-syntax syslog
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(lambda (s)
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"Like 'format', but write to syslog."
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(syntax-case s ()
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((_ fmt args ...)
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(string? (syntax->datum #'fmt))
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(with-syntax ((fmt (string-append "installer[~d]: "
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(syntax->datum #'fmt))))
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#'(format (syslog-port) fmt (getpid) args ...))))))
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(define (open-new-log-port)
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(define now (localtime (time-second (current-time))))
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(define filename
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(format #f "/tmp/installer.~a.log"
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(strftime "%F.%T" now)))
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(open filename (logior O_RDWR
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O_CREAT)))
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(define installer-log-port
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(let ((port #f))
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(lambda ()
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"Return an input and output port to the installer log."
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(unless port
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(set! port (open-new-log-port)))
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port)))
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(define (%installer-log-line-hook line)
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(format (installer-log-port) "~a~%" line))
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(define (%display-line-hook line)
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(display line)
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(newline))
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(define %default-installer-line-hooks
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(list %syslog-line-hook
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%installer-log-line-hook))
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(define-syntax installer-log-line
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(lambda (s)
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"Like 'format', but uses the default line hooks, and only formats one line."
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(syntax-case s ()
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((_ fmt args ...)
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(string? (syntax->datum #'fmt))
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#'(let ((formatted (format #f fmt args ...)))
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(for-each (lambda (f) (f formatted))
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%default-installer-line-hooks))))))
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;;;
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;;; Client protocol.
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;;;
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(define %client-socket-file
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;; Unix-domain socket where the installer accepts connections.
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"/var/guix/installer-socket")
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(define current-server-socket
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;; Socket on which the installer is currently accepting connections, or #f.
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(make-parameter #f))
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(define current-clients
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;; List of currently connected clients.
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(make-parameter '()))
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(define* (open-server-socket
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#:optional (socket-file %client-socket-file))
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"Open SOCKET-FILE as a Unix-domain socket to accept incoming connections and
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return it."
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(mkdir-p (dirname socket-file))
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(when (file-exists? socket-file)
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(delete-file socket-file))
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(let ((sock (socket AF_UNIX SOCK_STREAM 0)))
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(bind sock AF_UNIX socket-file)
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(listen sock 0)
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sock))
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(define (call-with-server-socket thunk)
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(if (current-server-socket)
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(thunk)
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(let ((socket (open-server-socket)))
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(dynamic-wind
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(const #t)
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(lambda ()
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(parameterize ((current-server-socket socket))
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(thunk)))
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(lambda ()
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(close-port socket))))))
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(define-syntax-rule (with-server-socket exp ...)
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"Evaluate EXP with 'current-server-socket' parameterized to a currently
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accepting socket."
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(call-with-server-socket (lambda () exp ...)))
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(define* (send-to-clients exp)
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"Send EXP to all the current clients."
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(define remainder
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(fold (lambda (client remainder)
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(catch 'system-error
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(lambda ()
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(write exp client)
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(newline client)
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(force-output client)
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(cons client remainder))
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(lambda args
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;; We might get EPIPE if the client disconnects; when that
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;; happens, remove CLIENT from the set of available clients.
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(let ((errno (system-error-errno args)))
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(if (memv errno (list EPIPE ECONNRESET ECONNABORTED))
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(begin
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(installer-log-line
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"removing client ~s due to ~s while replying"
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(fileno client) (strerror errno))
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(false-if-exception (close-port client))
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remainder)
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(cons client remainder))))))
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'()
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(current-clients)))
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(current-clients (reverse remainder))
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exp)
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(define-syntax-rule (with-silent-shepherd exp ...)
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"Evaluate EXP while discarding shepherd messages."
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(parameterize ((shepherd-message-port
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(%make-void-port "w")))
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exp ...))
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