Cinnamon on VNC on CentOS 7

Overview

This document describes how to install Cinnamon desktop environment on CentOS 7 for use in VNC. Basically, you can take a headless server and turn it into a virtual desktop controller.

Caveats

Limitations of this design prevent this from scaling up past so many users, so this would be best suited for home or small office use.
VNC uses no security. Consider alternatives or additions to this process when security is a consideration.

Installing Cinnamon for VNC

Installing the components

Install the vnc server.

yum install tigervnc-server tigervnc vnc

Install the desktop environment.

yum install cinnamon

Install any applications to be used.

yum install firefox gnome-terminal

Configuring the components

For each user that uses a virtual desktop on this host, you will need a separate systemd service, as well as a vnc password which is separate from the regular user password. Also set up the xstartup file for vnc.

tu=bgstack15
tn=1
sudo cp -p /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@\:${tn}.service
sed -r -i -e "s//${tu}/g;' /etc/systemd/system/vncserver@\:${tn}.service
systemctl enable vncserver@\:${tn}.service
firewall-cmd --permanent --add-port 59$( printf '%02i' "${tn}")/tcp
printf "For user ${tu} please provide new "
su - ${tu} -c vncpasswd
tf=~/.vnc/xstartup
test -f "${tf}" && \cp -p "${tf}" "${tf}.$( date "+%Y-%m-%dT%H%M%S" )"; touch "${tf}"; chmod 0755 "${tf}"
cat <<EOF > "${tf}"
unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
exec /usr/bin/cinnamon-session
EOF
systemctl start vncserver@\:${tn}.service

Connecting to the desktop

On a client, run

vncviewer hostname:1

Logout from Different Desktop Environments from Command Line

Rambling

Some people spend all day in terminals, even though there’s a desktop environment running. I normally have four different terminals open on my main screen, in a normal quadrant pattern. I arrange them on the taskbar so they are clockwise, starting in the upper left quadrant.

Problem

Suppose you want to close your session, without having to use the mouse or pressing the Super key or anything like that.

You want to enter a command from your terminal that will close your session. Here is a list of how to do that, for each different desktop environment (DE) I’ve collected so far.

Logout from desktop environments

Logout from cinnamon from command line

cinnamon-session-quit --logout --force

Logout from xfce from command line

xfce-session-quit -l

Logout from GNOME Shell from command line

­gnome-session-quit

Logout from KDE4 from command line

qdbus org.kde.ksmserver /KSMServer org.kde.KSMServerInterface.logout -1 -1 -1

Logout from KDE5 from command line

With confirmation

qdbus org.kde.ksmserver /KSMServer logout 1 3 3

Without confirmation

qdbus org.kde.ksmserver /KSMServer logout 0 3 3

Logout from desktop environment from command line

loginctl terminate-user username

References

Weblinks

  1. Cinnamon https://forums.linuxmint.com/viewtopic.php?t=177547
  2. Gnome https://askubuntu.com/questions/15795/how-can-you-log-out-via-the-terminal#15796
  3. KDE4 http://www.techlw.com/2012/07/log-out-in-ubuntu-from-command-line.html
  4. KDE5 Plasma https://forum.kde.org/viewtopic.php?f=289&t=135065
  5. Extra reading for KDE https://majewsky.wordpress.com/2009/07/11/shutdown-your-machine-automatically-or-from-remote/