1 前言

VNC在RHEL或CentOS的每个大版本的配置细节都有差异，笔者记录如下，给有需要的人参考。

2 实践部分

2.1 基础配置

2.1.1 安装基础包

yum groupinstall -y "Server with GUI"
yum install -y tigervnc-server

2.1.2 配置GDM-GNOME以传统X方式运行

vim /etc/gdm/custom.conf

去掉注解启用如下配置，

WaylandEnable=false

注：通过“false”变量声明系统下次启动时使用Xorg作为显示管理器而非Wayland

2.1.3 禁用SELinux

sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
setenforce 0

2.2 配置VNC

2.2.1 创建vnc密码

vncpasswd

向导如下，

Password:
Verify:
Would you like to enter a view-only password (y/n)? n
A view-only password is not used

2.2.2 配置启动服务

cp /usr/lib/systemd/user/vncserver@.service /etc/systemd/system/vncserver\@:1.service
vim /etc/systemd/system/vncserver\@:1.service

修改如下配置：

[Unit]
Description=Remote desktop service (VNC)
After=syslog.target network.target

[Service]
Type=forking

# Clean any existing files in /tmp/.X11-unix environment
ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
ExecStart=/usr/sbin/runuser -l root -c "/usr/bin/vncserver %i"
PIDFile=/root/.vnc/%H%i.pid
ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'

Restart=on-success
RestartSec=15

[Install]
WantedBy=default.target

2.3 启动服务

systemctl daemon-reload
systemctl start vncserver@:1.service
systemctl enable vncserver@:1.service

如果启动遇到如下错误提示，

localhost.localdomain systemd[1]: PID file /root/.vnc/localhost.localdomain:1.pid not readable (yet?) after start.

请按如下方法处理，

pgrep -u root Xvnc | xargs kill 2
rm -rf /tmp/.X11-unix/
reboot

如果无法启动可使用如下命令检查日志，

cat ~/.vnc/*.log

如果发现如下错误，

Xvnc TigerVNC 1.9.0 - built Feb  9 2019 10:21:52
Copyright (C) 1999-2018 TigerVNC Team and many others (see README.rst)
See http://www.tigervnc.org for information on TigerVNC.
Underlying X server release 12003000, The X.Org Foundation


Wed Oct 16 13:39:06 2019
 vncext:      VNC extension running!
 vncext:      Listening for VNC connections on all interface(s), port 5901
 vncext:      created VNC server for screen 0
dbus-update-activation-environment: error: unable to connect to D-Bus: Failed to connect to socket /tmp/dbus-khJAYpEYIO: Connection refused
GLib-GIO-Message: 13:39:10.060: Using the 'memory' GSettings backend.  Your settings will not be saved or shared with other applications.

** (process:6458): WARNING **: 13:39:10.079: Could not make bus activated clients aware of XDG_CURRENT_DESKTOP=GNOME environment variable: Could not connect: Connection refused
/root/.vnc/xstartup: line 6:  6458 Terminated              /etc/X11/xinit/xinitrc
Killing Xvnc process ID 6436

Wed Oct 16 13:39:10 2019
 ComparingUpdateTracker: 0 pixels in / 0 pixels out
 ComparingUpdateTracker: (1:-nan ratio)

通过如下命令确定总线启动程序的位置，

whereis dbus-launch

可见如下显示，

dbus-launch: /usr/bin/dbus-launch /usr/anaconda3/bin/dbus-launch /usr/share/man/man1/dbus-launch.1.gz

从上面可知，默认启动总线程序有两个，系统默认的应为“/usr/bin/dbus-launch”，可使用如下命令解决，

vim /etc/X11/xinit/xinitrc.d/00-start-message-bus.sh

修总线程序的执行文件为绝对路径，配置修改如下，

#!/bin/sh
if [ -z "$DBUS_SESSION_BUS_ADDRESS" ]; then
        eval `/usr/bin/dbus-launch --sh-syntax --exit-with-session`
fi

注：将启动总线程序改为绝对路径的“/usr/bin/dbus-launch”防止去启动错误的总线启动程序“/usr/anaconda3/bin/dbus-launch”即可修复此问题。

2.4 优化VNC

2.4.1 修改VNC的起始端口

cp /usr/bin/vncserver /usr/bin/vncserver.default
vim /usr/bin/vncserver

修改如下变量的赋值：

$vncPort = 5899 + $displayNumber;

2.4.2 重启服务使配置生效

systemctl restart vncserver@:1.service

2.4.3 确认端口修改成功

netstat -tunlp | grep -i vnc

2.4.4 配置防火墙

firewall-cmd --permanent --add-port 5900/tcp
firewall-cmd  --reload
firewall-cmd --list-all

2.5 其他服务管理命令

vncserver -list
vncserver -kill :1

参阅文档
=================
RHEL或CentOS 7的VNC的配置
———————-
https://www.cmdschool.org/archives/1884

TigerVNC的配置
——————-
https://wiki.archlinux.org/index.php/TigerVNC