How to Enable Remote Desktop Access for CentOS 7

Question

Having SSH access to a server I need to install and configure remote access using a Command Line Interface, To access Server using VNC or Terminal Server Client

To enable the GUI:

yum -y groupinstall "GNOME Desktop" && systemctl set-default graphical.target && shutdown -r now

But I can't find any solution for enabling Remote Administrative Access using command line only. CentOS documentation shows how to do it using a GUI (if you have access to GUI), but nothing about command-line options or at least which config files are getting edited with GUI interface in this case...

https://www.centos.org/docs/4/html/rhd-dg-en-4/ch-ddg-remote-desktop.html

Does anyone knows how to do it?

Answer 1

Given are the steps to install and configure VNC server in centOs:

1. ~]# yum install tigervnc-server
2. ~]# cp /usr/lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:1.service
3. ~]# vim /etc/systemd/system/vncserver@:1.service

replaced USER with riddhi in this file

ExecStart=/usr/sbin/runuser -l USER -c "/usr/bin/vncserver %i -geometry 1280x1024"
PIDFile=/home/USER/.vnc/%H%i.pid

4. ~]# systemctl daemon-reload
5. ~]# su - riddhi
6. ~]$ vncpasswd //update password for user riddhi
7. ~]# systemctl start vncserver@:1.service
8. ~]# systemctl enable vncserver@:1.service

Now connect to centOs from Windows:

1. IP: ip address:5901

2. password : password of vncpasswd

Answer 2

If you are looking to enable remote access to the 'root' account and you are willing to accept those risks, then uncomment the following line in /etc/ssh/sshd_config

PermitRootLogin yes

Then restart the ssh daemon

service sshd restart

then you can SSH into the system with

ssh root@SERVER_IP_ADDRESS

If you are using another user then of course you could just

ssh username@SERVER_IP_ADDRESS

If you are getting and Access Denied I would turn off the firewall to verify if that is the issue or not.

A slightly less risky alternative would be to setup ssh keypairs (so you don't need to type in your password every time you connect). And also configure your user so that they aren't prompted for a root password every time you sudo.

Answer 3

Installing VNC worked for me, so it seems in CentOS7, nothing really needs to be enabled trough (GUI) for instance from GNOME. Created a small script so anyone else can use if needed. for CentOS7

yum -y groupinstall "GNOME Desktop" && 
systemctl set-default graphical.target && 
yum install -y tigervnc-server &&
cp /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:4.service &&
systemctl enable vncserver@:4.service   &&
sed -i 's/<USER>/root/g' /etc/systemd/system/vncserver@:4.service &&
cp /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:5.service &&
cat <<"EOF" >> /etc/systemd/system/vncserver@:5.service
[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 || :'
EOF
systemctl enable vncserver@:5.service &&
#  Setting Firewall rules
firewall-cmd --permanent --zone=public --add-port=5904-5905/tcp &&
firewall-cmd --reload &&
#setting password for vnc access
vncserver &&
#restarting services
systemctl daemon-reload &&
systemctl restart vncserver@:4.service &&
systemctl restart vncserver@:5.service &&
shutdown -r now 

On this stage you should be able to log in using VNC client. For me "Realvnc" worked fine others did not for some strange reason... Please note :

1. connection ports are 5904 and 5905
2. If you need more simultanius connections to be enabled for free ;) Unlike Windows :), just add more :
   • /etc/systemd/system/vncserver@:6.service
   • /etc/systemd/system/vncserver@:7.service
   • /etc/systemd/system/vncserver@:8.service
     etc... and make sure ports 5906,5907,5908 are not busy with some other app.
3. Firewall rule may need to be altered, depending to what zone your network interface belongs to.