How to Install X2GO Remote Desktop Server in CentOS 7 Linux

X2go is remote desktop solution capable of providing encrypted desktop session over low bandwidth, high latency links. It is similar to VNC but with built-in encryption. We are using x2go for replacement of Oracle Sunray solution.

This post is part of series where we are going to setup VDI solution based on open source components. Previously, we have setup DHCP server ,TFTP server and yum repository server. Now, we will install x2go server components.

We will be using the same machine on which we have configured DHCP server.

x2go use ssh connection for encryption. We can use ssh service which come with operating system. However, we may not be able to enable few of the features in existing ssh configuration which are required for x2go if you have hardened ssh e.g. disable port forwarding. Therefore, we are going to set up a new systemd service with a different ssh configuration but same using the ssh binary.

I have selected tcp port 2748 for running separate ssh daemon on which I will connect from x2go client. Open this port in firewall.

firewall-cmd --zone=public --add-port=2748/tcp --permanent

Reload the firewall to re-read the configuration.

firewall-cmd –reload

Copy the existing sshd configuration file to a new file in which we can make changes.

cp /etc/ssh/sshd_config /etc/ssh/sshd_config_x2go

Change the listening port to 2748 in new file.

sed -i -e 's/#Port 22/Port 2748/g' /etc/ssh/sshd_config_x2go

We are going to create a new service for new ssh daemon

>/usr/lib/systemd/system/x2go-sshd.service

Paste the following line on terminal which will append the content to newly create service file

cat > /usr/lib/systemd/system/x2go-sshd.service <<EOF
[Unit]
Description=X2GO-OpenSSH server daemon
Documentation=man:sshd(8) man:sshd_config(5)
After=network.target sshd-keygen.service
Wants=sshd-keygen.service

[Service]
Type=notify
EnvironmentFile=/etc/sysconfig/sshd
#ExecStart=/usr/sbin/sshd -D $OPTIONS
ExecStart=/usr/sbin/sshd -D -f /etc/ssh/sshd_config_x2go $OPTIONS

ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
RestartSec=42s

[Install]
WantedBy=multi-user.target
EOF

Reload the systemd daemon to detect this newly created service

systemctl daemon-reload

Start the new service and enable it on startup

systemctl enable x2go-sshd.service && systemctl restart x2go-sshd.service

Now, we are going to install GUI components. Following commands are going to deploy minimal number of packages for GUI based environment. X2go has best compatibility with XFCE. Therefore, we will be using XFCE environment.

yum groupinstall -y Fonts
yum install -y xfdesktop xorg-x11-server-Xorg xorg-x11-xinit xorg-x11-font-utils xorg-x11-xauth xorg-x11-utils xorg-x11-fonts* lightdm xfce4-session xfce4-session-engines xfce4-settings xfce4-terminal Thunar tumbler xscreensaver

As I am using virtual machine therefore it is good practice to install vm tools along with x11 drivers.

yum install open-vm-tools-desktop.x86_64 xorg-x11-drv-evdev

Now the desktop environment is ready, we can test if it is working fine by using rebooting the machine which will load GUI on next run.

reboot

Once machine is back online, install x2go package

yum install x2goserver x2goserver-xsession

Enable the x2go session service

systemctl enable x2gocleansessions.service

X2go provides the ability to copy the clipboard. This option can be disabled from server side to ensure data leakage protection.

sed -i 's/#X2GO_NXAGENT_DEFAULT_OPTIONS+=\" -clipboard both\"/X2GO_NXAGENT_DEFAULT_OPTIONS+=\" -clipboard none\"/g' /etc/x2go/x2goagent.options

XFCE displays the drives on user desktop. This can be disabled using following code

>/etc/xdg/xfce4/xfconf/xfce-perchannel-xml/xfce4-desktop.xml
cat > /etc/xdg/xfce4/xfconf/xfce-perchannel-xml/xfce4-desktop.xml <<'EOF'
<?xml version="1.0" encoding="UTF-8"?>

<channel name="xfce4-desktop" version="1.0">
  <property name="backdrop" type="empty">
    <property name="screen0" type="empty">
      <property name="monitor0" type="empty">
        <property name="workspace0" type="empty">
          <property name="color-style" type="int" value="0"/>
          <property name="image-style" type="int" value="5"/>
          <property name="last-image" type="string" value="/usr/share/backgrounds/images/default.png"/>
        </property>
        <property name="workspace1" type="empty">
          <property name="color-style" type="int" value="0"/>
          <property name="image-style" type="int" value="5"/>
          <property name="last-image" type="string" value="/usr/share/backgrounds/images/default.png"/>
        </property>
        <property name="workspace2" type="empty">
          <property name="color-style" type="int" value="0"/>
          <property name="image-style" type="int" value="5"/>
          <property name="last-image" type="string" value="/usr/share/backgrounds/images/default.png"/>
        </property>
        <property name="workspace3" type="empty">
          <property name="color-style" type="int" value="0"/>
          <property name="image-style" type="int" value="5"/>
          <property name="last-image" type="string" value="/usr/share/backgrounds/images/default.png"/>
        </property>
      </property>
    </property>
  </property>
  <property name="desktop-icons" type="empty">
    <property name="file-icons" type="empty">
      <property name="show-filesystem" type="bool" value="false"/>
      <property name="show-removable" type="bool" value="false"/>
      <property name="show-trash" type="bool" value="true"/>
    </property>
  </property>
  <property name="last" type="empty">
    <property name="window-width" type="int" value="672"/>
    <property name="window-height" type="int" value="551"/>
  </property>
</channel>
EOF

Reboot the system one more time