How to setup a GUI via VNC for your Oracle Linux Compute Instance in Oracle Cloud Infrastructure (OCI)

In a couple previous posts, I explained how to get an “Always Free” Oracle Cloud compute instance and how to install MySQL on it – as well as how to add a web server.

I started my IT career (way back in 1989) using a (dumb) terminal and a 2400-baud modem to access a server. While I still use a terminal window and the command-line, it is always nice to have access to a GUI. In this post, I will show you how to install and use a GUI on your Oracle Cloud compute instance so you can use a Virtual Network Computing (VNC) application to connect to your “Always Free” (or not-free) Oracle Cloud compute instance.

VNC is a graphical desktop-sharing system that uses the Remote Frame Buffer protocol to remotely control another computer. In other words, it is (almost) like having a monitor connected to your compute instance. Installing everything you need should take about twenty minutes (only because one yum install takes 13-15 minutes).

First, you will need to create your “Always Free” Oracle Cloud account, and at least one free compute instance. (Of course, this will also work on a paid compute instance.) If you need help creating your free compute instance, you can follow the instructions in the first part of this post (installing MySQL is optional).

Once you have your compute instance ready to go, or if you already have an compute instance running, you can continue with this post.

VNC Viewer

I am using a Mac, so I can use the Screen Sharing application that comes with the operating system (OS). If you don’t have a Mac, you will need to find a VNC application for your OS. I have also used the free (non-commercial-use only) version of VNC Connect from RealVNC, but you will need to buy a copy of you are using it for work. But there are several free ones available, such as TeamViewer, TightVNC and TigerVNC.

If you don’t use a Mac, I won’t be able to show you how to install or setup the VNC viewer you decide to use, but it should be easy to do. Whichever VNC app you choose should provide you with instructions. You should only have to input localhost and the port number of 5901.

Installing what you need on your compute instance

Login to your compute instance. When I created my compute instance, I chose to install Oracle Linux. These instructions should work for any other flavor of Linux, but if not, you can look for the similar packages for your OS and you might have to modify a few things.

You can use yum (a tool for downloading, installing, deleting, querying, and managing software packages) to install the GNOME desktop, which is a free and open-source desktop environment. This installation is 678 megabytes in size, and it will take about 13-15 minutes. You can remove the -y option to your yum command if you want to answer “yes” to the single installation question of “Is this ok?”.

Note: Normally I would post the entire output from a command, but the output is almost 6,000 lines long. I will replace the majority of the screen output with three dots (…).

$ sudo yum -y groups install "Server with GUI" 
Loaded plugins: langpacks, ulninfo
Repository ol7_latest is listed more than once in the configuration
...
Transaction Summary
==================================================
Install  209 Packages (+659 Dependent packages)
Upgrade               (   3 Dependent packages)

Total download size: 678 M
Is this ok [y/d/N]: y
Downloading packages:
...
Complete!

Install the TigerVNC server. (I will suppress most of this output as well)

$ sudo yum -y install tigervnc-server
Loaded plugins: langpacks, ulninfo
...
Resolving Dependencies
--> Running transaction check
---> Package tigervnc-server.x86_64 0:1.8.0-17.0.1.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

====================================================================
 Package           Arch      Version             Repository    Size
====================================================================
Installing:
 tigervnc-server   x86_64    1.8.0-17.0.1.el7    ol7_latest   215 k
Transaction Summary
====================================================================
Install  1 Package

Total download size: 215 k
Installed size: 509 k
Downloading packages:
tigervnc-server-1.8.0-17.0.1.el7.x86_64.rpm         | 215 kB  00:00:00     
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : tigervnc-server-1.8.0-17.0.1.el7.x86_64       1/1 
  Verifying  : tigervnc-server-1.8.0-17.0.1.el7.x86_64       1/1 

Installed:
  tigervnc-server.x86_64 0:1.8.0-17.0.1.el7
Complete!

Configure the VNC server

You will be required to provide a password that you will need to remember to be able to access this server via VNC. You can also enter a “view-only password” if you want someone to be able to connect to the server, but you don’t want them to be able to control anything (they can only view the screen). I skipped this option.

$ vncserver
You will require a password to access your desktops.
Password:
Verify:
Would you like to enter a view-only password (y/n)? n
A view-only password is not used
xauth:  file /home/opc/.Xauthority does not exist

New 'instance-20191113-1544:1 (opc)' desktop is instance-20191113-1544:1

Creating default startup script /home/opc/.vnc/xstartup
Creating default config /home/opc/.vnc/config
Starting applications specified in /home/opc/.vnc/xstartup
Log file is /home/opc/.vnc/instance-20191113-1544:1.log

SSH Tunnel for VNC

I am going to create a tunnel for VNC through SSH, so I can punch through the VNC port, and also so I will be sending all of the data through an encrypted tunnel.

Note: There is an alternate way to access your compute instance via VNC by creating an Instance Console Connection, but it only provides you with a console connection (non-GUI). If you want to do that, instructions are available via this blog.

In a terminal window, issue the following command, with your public IP address at the end. This will create the SSH tunnel for you to use for VNC.

$ ssh -L 5901:localhost:5901 opc@150.136.199.99

Now you are ready to connect to the instance using VNC. For the Mac, I open the Screen Sharing application, click on the menu option “Connection” then down to “New”. In the “Connect to” box, I enter localhost:5901 and press “Connect”.

And then enter the password you used when you ran the vncserver command earlier.

If you are using another VNC viewer, simply enter localhost:5901, or you might have to enter localhost and the port 5901 in separate fields.

Then, just open the connection with your VNC application, and you should be see the Oracle Linux GUI appear:

You will have to go through a few setup screens the first time you connect.

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Alternatives to GNOME

If you are using the “Always Free” OCI instances, you can also consider using two lightweight alternate GUI’s. You can also install MATE or Xfce.

Multiple connections

If you want to have multiple connections open to separate OCI instances at the same time, you can do this by changing the outgoing port on your SSH tunnel. The syntax for the ssh tunnel command contains two port numbers. The outgoing port (on your machine) is 5902, and the destination/incoming port is 5901. So, to open a second SSH tunnel to connect to a separate OCI instance, you can run this:

$ ssh -L 5902:localhost:5901 opc@150.136.199.98

This syntax follows the ssh man page: -L [bind_address:]port:host:hostport.

Now you know how to use VNC to connect to your Oracle Compute Cloud Instance.

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Many thanks to Pilippe Vanhaesendonck for sharing his technical expertise.

 

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	Tony Darnell is a Principal Sales Consultant for MySQL, a division of Oracle, Inc. MySQL is the world’s most popular open-source database program. Tony may be reached at info [at] ScriptingMySQL.com and on LinkedIn.
	Tony is the author of Twenty Forty-Four: The League of Patriots  Visit http://2044thebook.com for more information.
	Tony is the editor/illustrator for NASA Graphics Standards Manual Remastered Edition  Visit https://amzn.to/2oPFLI0 for more information.

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