在 Ubuntu Maverick 中启动系统时让 Xvfb 启动

Question

当系统在 Ubuntu 10.10 (Maverick) 上启动时，我试图让 Xvfb 运行，但它不起作用。在 /etc/rc.local 中，我有以下内容：

/root/start_xvfb.sh >> /var/log/start_xvfb.log 2>&1
exit 0

在 /root/start_xvfb.sh 我有：

#!/bin/sh -e
startx -- `which Xvfb` :0 -screen 0 1024x768x24 &
exit 0

重新启动机器后，日志文件 (/var/log/start_xvfb.log) 包含：

[dix] Could not init font path element /usr/share/fonts/X11/cyrillic, removing from list!
^M
waiting for X server to shut down
^M

鉴于日志文件中的内容，似乎正在调用“startx -- `which Xvfb` :0 -screen 0 1024x768x24”，但此后不久该进程就被终止了。

我想在启动时启动 Xvfb，因为我需要在没有监视器显示的远程服务器上运行 Firefox。如果我在通过 SSH 连接到远程机器后运行 /etc/rc.local，Xvfb 启动没有问题，我可以通过“firefox --display=:0 &”启动 Firefox。如果我在没有先启动 Xvfb 的情况下尝试使用该命令运行 Firefox，我会收到消息“错误：无法打开显示：:0”。

请注意，我并不是要实际查看本地工作站上的显示。我希望应用程序显示在远程机器的（虚拟的，内存中的）显示器上。

任何想法为什么 X 服务器在启动后立即在远程机器上关闭？有没有更好的方法让 Xvfb 在系统启动时启动？

在此先感谢您的帮助。

Answer 1

我想 shell 在退出时会对它进行 TERM，这将是立即的，因为 '&'。也许你想使用 start-stop-daemon？例如：

start-stop-daemon --start -b -x /usr/bin/Xvfb :1

我想如果您需要 startx 包装器的帮助，您可能需要运行您的 shellscript。

Answer 2

您可以使用我的初始化脚本。它基于 /etc/init.d/skeleton 并且似乎运行良好：

#! /bin/sh
### BEGIN INIT INFO
# Provides:          Xvfb
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start Xvfb.
# Description:       Start the X virtual framebuffer.
### END INIT INFO

# Author: Hannes Brandstaetter-Mueller <hannes.brandstaetter@fh-hagenberg.at>
#
# Please remove the "Author" lines above and replace them
# with your own name if you copy and modify this script.

# Do NOT "set -e" 

# PATH should only include /usr/* if it runs after the mountnfs.sh script
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="X virtual framebuffer" 
NAME="Xvfb" 
DAEMON=/usr/bin/$NAME
DAEMON_ARGS=":1 -screen 0 640x480x24" 
PIDFILE=/var/run/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME

# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0

# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME

# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
. /lib/lsb/init-functions

#
# Function that starts the daemon/service
#
do_start()
{
        # Return
        #   0 if daemon has been started
        #   1 if daemon was already running
        #   2 if daemon could not be started
        start-stop-daemon --start --background --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
                || return 1
        start-stop-daemon --start --background --quiet --pidfile $PIDFILE --exec $DAEMON -- \
                $DAEMON_ARGS \
                || return 2
        # Add code here, if necessary, that waits for the process to be ready
        # to handle requests from services started subsequently which depend
        # on this one.  As a last resort, sleep for some time.
}

#
# Function that stops the daemon/service
#
do_stop()
{
        # Return
        #   0 if daemon has been stopped
        #   1 if daemon was already stopped
        #   2 if daemon could not be stopped
        #   other if a failure occurred
        start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME
        RETVAL="$?" 
        [ "$RETVAL" = 2 ] && return 2
        # Wait for children to finish too if this is a daemon that forks
        # and if the daemon is only ever run from this initscript.
        # If the above conditions are not satisfied then add some other code
        # that waits for the process to drop all resources that could be
        # needed by services started subsequently.  A last resort is to
        # sleep for some time.
        start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --exec $DAEMON
        [ "$?" = 2 ] && return 2
        # Many daemons don't delete their pidfiles when they exit.
        rm -f $PIDFILE
        return "$RETVAL" 
}

#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
        #
        # If the daemon can reload its configuration without
        # restarting (for example, when it is sent a SIGHUP),
        # then implement that here.
        #
        start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME
        return 0
}

case "$1" in
  start)
        [ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME" 
        do_start
        case "$?" in
                0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
                2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
        esac
        ;;
  stop)
        [ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME" 
        do_stop
        case "$?" in
                0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
                2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
        esac
        ;;
  status)
       status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
       ;;
  #reload|force-reload)
        #
        # If do_reload() is not implemented then leave this commented out
        # and leave 'force-reload' as an alias for 'restart'.
        #
        #log_daemon_msg "Reloading $DESC" "$NAME" 
        #do_reload
        #log_end_msg $?
        #;;
  restart|force-reload)
        #
        # If the "reload" option is implemented then remove the
        # 'force-reload' alias
        #
        log_daemon_msg "Restarting $DESC" "$NAME" 
        do_stop
        case "$?" in
          0|1)
                do_start
                case "$?" in
                        0) log_end_msg 0 ;;
                        1) log_end_msg 1 ;; # Old process is still running
                        *) log_end_msg 1 ;; # Failed to start
                esac
                ;;
          *)
                # Failed to stop
                log_end_msg 1
                ;;
        esac
        ;;
  *)
        #echo "Usage: $SCRIPTNAME {start|stop|restart|reload|force-reload}" >&2
        echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
        exit 3
        ;;
esac

把它放进去/etc/init.d/xvfbd然后运行

sudo update-rc.d xvfbd defaults

现在它应该在启动时自动运行。