;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018, 2020 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2019, 2020, 2022 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 (gnu services herd)
#:use-module (guix utils)
#:use-module ((guix build syscalls) #:select (openpty login-tty))
#:use-module (guix build utils)
#:use-module (guix i18n)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-9 gnu)
#:use-module (srfi srfi-19)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-35)
#:use-module (ice-9 control)
#:use-module (ice-9 match)
#:use-module (ice-9 popen)
#:use-module (ice-9 rdelim)
#:use-module (ice-9 regex)
#:use-module (ice-9 format)
#:use-module (ice-9 textual-ports)
#:export (<secret>
secret?
make-secret
secret-content
read-lines
read-all
nearest-exact-integer
read-percentage
run-external-command-with-handler
run-external-command-with-handler/tty
run-external-command-with-line-hooks
run-command
run-command-in-installer
syslog-port
%syslog-line-hook
installer-log-port
%installer-log-line-hook
%default-installer-line-hooks
installer-log-line
call-with-time
let/time
with-server-socket
current-server-socket
current-clients
send-to-clients
with-silent-shepherd))
(define-record-type <secret>
(make-secret content)
secret?
(content secret-content))
(set-record-type-printer!
<secret>
(lambda (secret port)
(format port "<secret>")))
(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-external-command-with-handler handler command)
"Run command specified by the list COMMAND in a child with output handler
HANDLER. HANDLER is a procedure taking an input port, to which the command
will write its standard output and error. Returns the integer status value of
the child process as returned by waitpid."
(match-let (((input . output) (pipe)))
;; Hack to work around Guile bug 52835
(define dup-output (duplicate-port output "w"))
;; Void pipe, but holds the pid for close-pipe.
(define dummy-pipe
(with-input-from-file "/dev/null"
(lambda ()
(with-output-to-port output
(lambda ()
(with-error-to-port dup-output
(lambda ()
(apply open-pipe* (cons "" command)))))))))
(close-port output)
(close-port dup-output)
(handler input)
(close-port input)
(close-pipe dummy-pipe)))
(define (run-external-command-with-handler/tty handler command)
"Run command specified by the list COMMAND in a child operating in a
pseudoterminal with output handler HANDLER. HANDLER is a procedure taking an
input port, to which the command will write its standard output and error.
Returns the integer status value of the child process as returned by waitpid."
(define-values (controller inferior)
(openpty))
(match (primitive-fork)
(0
(catch #t
(lambda ()
(close-fdes controller)
(login-tty inferior)
(apply execlp (car command) command))
(lambda _
(primitive-exit 127))))
(pid
(close-fdes inferior)
(let* ((port (fdopen controller "r0"))
(result (false-if-exception
(handler port))))
(close-port port)
(cdr (waitpid pid))))))
(define* (run-external-command-with-line-hooks line-hooks command
#:key (tty? #false))
"Run command specified by the list COMMAND in a child, processing each
output line with the procedures in LINE-HOOKS. If TTY is set to #true, the
COMMAND will be run in a pseudoterminal. Returns the integer status value of
the child process as returned by waitpid."
(define (handler input)
(and
;; Lines for progress bars etc. end in \r; treat is as a line ending so
;; those lines are printed right away.
(and=> (read-delimited "\r\n" input 'concat)
(lambda (line)
(if (eof-object? line)
#f
(begin (for-each (lambda (f) (f line))
(append line-hooks
%default-installer-line-hooks))
#t))))
(handler input)))
(if tty?
(run-external-command-with-handler/tty handler command)
(run-external-command-with-handler handler command)))
(define* (run-command command #:key (tty? #f))
"Run COMMAND, a list of strings. Return true if COMMAND exited
successfully, #f otherwise. If TTY is set to #true, the COMMAND will be run
in a pseudoterminal."
(define (pause)
(format #t (G_ "Press Enter to continue.~%"))
(send-to-clients '(pause))
(match (select (cons (current-input-port) (current-clients))
'() '())
(((port _ ...) _ _)
(read-line port))))
(installer-log-line "running command ~s" command)
(define result (run-external-command-with-line-hooks
(list display) command
#:tty? tty?))
(define exit-val (status:exit-val result))
(define term-sig (status:term-sig result))
(define stop-sig (status:stop-sig result))
(define succeeded?
(cond
((and exit-val (not (zero? exit-val)))
(installer-log-line "command ~s exited with value ~a"
command exit-val)
(format #t (G_ "Command ~s exited with value ~a")
command exit-val)
#f)
(term-sig
(installer-log-line "command ~s killed by signal ~a"
command term-sig)
(format #t (G_ "Command ~s killed by signal ~a")
command term-sig)
#f)
(stop-sig
(installer-log-line "command ~s stopped by signal ~a"
command stop-sig)
(format #t (G_ "Command ~s stopped by signal ~a")
command stop-sig)
#f)
(else
(installer-log-line "command ~s succeeded" command)
(format #t (G_ "Command ~s succeeded") command)
#t)))
(newline)
(pause)
succeeded?)
(define run-command-in-installer
(make-parameter
(lambda (. args)
(raise
(condition
(&serious)
(&message (message "run-command-in-installer not set")))))))
;;;
;;; Logging.
;;;
(define (call-with-time thunk kont)
"Call THUNK and pass KONT the elapsed time followed by THUNK's return
values."
(let* ((start (current-time time-monotonic))
(result (call-with-values thunk list))
(end (current-time time-monotonic)))
(apply kont (time-difference end start) result)))
(define-syntax-rule (let/time ((time result exp)) body ...)
(call-with-time (lambda () exp) (lambda (time result) body ...)))
(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 (%syslog-line-hook line)
(let ((line (if (string-suffix? "\r" line)
(string-append (string-drop-right line 1) "\n")
line)))
(format (syslog-port) "installer[~d]: ~a" (getpid) line)))
(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 ...))))))
(define (open-new-log-port)
(define now (localtime (time-second (current-time))))
(define filename
(format #f "/tmp/installer.~a.log"
(strftime "%F.%T" now)))
(open filename (logior O_RDWR
O_CREAT)))
(define installer-log-port
(let ((port #f))
(lambda ()
"Return an input and output port to the installer log."
(unless port
(set! port (open-new-log-port)))
port)))
(define (%installer-log-line-hook line)
(display line (installer-log-port)))
(define %default-installer-line-hooks
(list %syslog-line-hook
%installer-log-line-hook))
(define-syntax installer-log-line
(lambda (s)
"Like 'format', but uses the default line hooks, and only formats one line."
(syntax-case s ()
((_ fmt args ...)
(string? (syntax->datum #'fmt))
(with-syntax ((fmt (string-append (syntax->datum #'fmt) "\n")))
#'(let ((formatted (format #f fmt args ...)))
(for-each (lambda (f) (f formatted))
%default-installer-line-hooks)))))))
;;;
;;; 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
(installer-log-line
"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)
(define-syntax-rule (with-silent-shepherd exp ...)
"Evaluate EXP while discarding shepherd messages."
(parameterize ((shepherd-message-port
(%make-void-port "w")))
exp ...))
