1. This document provides instructions for creating a headless Ubuntu/XFCE container using Docker and Dockerfish. 2. It shows how to install Dockerfish, pull the Ubuntu image, create and run a container, install XFCE and VNC, and export the container configuration to a new reusable image. 3. Key steps include cloning the Dockerfish repo, pulling the Ubuntu image, running the container with XFCE and VNC installed, checking the container IP, and using Dockerfish to commit the container configuration to a new image called devel/headless-ubuntu-vnc.

1. How to build a headless Ubuntu / XFCE with Docker & Dockerfish
Make sure you have Docker installed first and foremost.
Getting started
This tutorial demonstrates the ease of use of my tool Dockerfish which i coded from the ground up in pure Ruby
it requires no gems so there is no messing about.
I also showyou then how make a image from your containerwith ease also.
All you have todo is have git installed and most developers have it installed as a no brainer.
if not apt-get install git for Ubuntu / Debian or yum install git for Centos / Fedora etc ...
cd into the folder of your choice to download into then.
git clone https://github.com/puppetpies/DockerFish-CLI.git
Check if docker is running
systemctl status docker.service
docker.service - DockerApplicationContainer Engine
Loaded: loaded(/usr/lib/systemd/system/docker.service; enabled)
Active: active (running) since Fri 2015-06-26 10:21:28BST; 46minago
Docs: http://docs.docker.io
Process: 786 ExecStartPre=/usr/bin/mount --make-rprivate/ (code=exited, status=0/SUCCESS)
Main PID: 792 (docker)
CGroup: /system.slice/docker.service
792 /usr/bin/docker --api-enable-cors=true -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock -d
Makingsure the APIis enabledyour docker.service ExecStart lineshouldlooklike this.
-H tcp://0.0.0.0:2375 - Youmay want torestrict this to certaininterface/ ip address as this what DockerFishwill access the API via.
cat /etc/systemd/system/multi-user.target.wants/docker.service
[Unit]
Description=DockerApplicationContainer Engine
Documentation=http://docs.docker.io
After=network.target
[Service]
ExecStartPre=/usr/bin/mount --make-rprivate /
ExecStart=/usr/bin/docker--api-enable-cors=true -H tcp://0.0.0.0:2375-H unix:///var/run/docker.sock -d
[Install]
WantedBy=multi-user.target
If you have had to make changes to this file then do the below.
systemctl daemon-reload
Then restart Docker where convieniant.
systemctl restart docker.service

2. Now check if Docker has started up correctly systemctl status docker.service if all is well lets download Ubuntu.
docker pull ubuntu
This may take sometime but its worth the wait.
Introduction to Dockerfish
Make yourdockerfish.rb executable
chmod 755 dockerfish.rb
symlink to /usr/bin # You need root for this and optional
ln -s dockerfish.rb /usr/bin/dockerfish
./dockerfish.rb
Welcome toDockerFishVersion 0.1
---------------------------------
Interactive CLIDocker Interface
[] |
|
,|.
,|/.
,' .V. `.
/ . . /_`
|@)| . . |(@|
,-._ `._'; . :`_,'_,-.
'-- `- /,-===-. /-' --`
(---- _| ||___|| |_ ----)
`._,-' `-.-' / `-._,'
`-.___,-' ap[]
TIPS: Please note ContainerId's / Names are interchangeable
Youcan also use short ContainerId's as longas there is a unique match
Start with Docker API Enabled: /usr/bin/docker --api-enable-cors=true -H tcp://127.0.0.1:2375 -H unix:///var/run/docker.sock -d
Add a symlink ln -s /home/brian/Projects/DockerFish/dockerfish.rb/usr/bin/dockerfish
--help # For more information
Enjoy!
Coded by Brian Hood
Server Info:
{"ApiVersion"=>"1.18",
"Arch"=>"amd64",
"GitCommit"=>"a61716e",
"GoVersion"=>"go1.4.2",
"KernelVersion"=>"3.14.5-1-ARCH",
"Os"=>"linux",
"Version"=>"1.5.0-dev"}
DockerFish> 1
List of DockerImages
=====================
Created: 2015-06-12 16:32:30 Id: 6d4946999d4fb403f4 Image: ["ubuntu:latest"] Size: 8B VirtualSize: 179.563MB
You now have the latest Ubuntu image at your finger tips great so what now ?
The first step is press 6 and hit enter.

3. 6) Create Container from Image
Enter Image touse> ubuntu:latest
Example: name orname1,name2,name3
Enter Container name(s)> ubuntu-xfce-headless
{
"Hostname":"ubuntu-xfce-headless",
"User":"",
"Memory":0,
"MemorySwap":0,
"CpuShares":0,
"AttachStdin":true,
"AttachStdout":true,
"AttachStderr":true,
"PortSpecs":null,
"Tty":true,
"OpenStdin":true,
"StdinOnce":true,
"Env":null,
"Cmd":[
"/bin/bash"
],
"Dns":null,
"Image":"ubuntu:latest",
"VolumesFrom":"",
"WorkingDir":"",
"HostConfig": {
"NetworkMode": "bridge",
"Devices": []
}
}
ContainerCreationSuccessfull
DockerFish> 2
List of DockerContainers
=========================
Command: /bin/bash ContainerId: 5073abe5f5c9 Image: ubuntu:latest Names: ["/ubuntu-xfce-headless"] Status:
Ok lets start up your container.
Press 3
DockerFish> 3
Enter Container to Start> ubuntu-xfce-headless
StartingContainer ubuntu-xfce-headless
Start Successfull
DockerFish> 2
List of DockerContainers
=========================
Command: /bin/bash ContainerId: 5073abe5f5c9 Image: ubuntu:latest Names: ["/ubuntu-xfce-headless"] Status: Up 48 seconds
Was it really that easy to yes in short now you just have todo the configuration in the next step.
Build your machine from scratch
Startup and Terminal
To attach to your docker instance run the folllowing.
docker attach ubuntu-xfce-headless

4. Then hit enter again to enter the container.
[brian@orville ~]$dockerattachubuntu-xfce-headless
root@ubuntu-xfce-headless:/# apt-get update
Ign http://archive.ubuntu.comtrustyInRelease
Ign http://archive.ubuntu.comtrusty-updates InRelease
Ign http://archive.ubuntu.comtrusty-securityInRelease
Hit http://archive.ubuntu.com trusty Release.gpg
Get:1 http://archive.ubuntu.com trusty-updates Release.gpg[933 B]
Get:2 http://archive.ubuntu.com trusty-securityRelease.gpg[933 B]
-- OMITTED --
Ok so youobtainedthe latest Ubunturepository dataif youdon’t knowwhat the means don’t worry.
Next downloadXFCE4
root@ubuntu-xfce-headless:/# apt-get install xfce4xvfbx11vnc
Readingpackage lists... Done
Building dependency tree
Readingstate information... Done
The followingextra packages will be installed:
-- OMITTED LOTSOF PACKAGES--
2 upgraded, 384 newly installed, 0 toremove and9 not upgraded.
Needto get 94.4 MB ofarchives.
After this operation,378MB of additional disk space will be used.
Do youwant to continue? [Y/n]
Press Y enter and sit back and relax read a book etc ...
Setup VNC / Xvfb
root@ubuntu-xfce-headless:/# mkdir ~/.vnc
root@ubuntu-xfce-headless:/# x11vnc -storepasswdletmein ~/.vnc/passwd
root@ubuntu-xfce-headless:/# Xvfb:1 -extensionGLX -screen0 1024x780x24 &
root@ubuntu-xfce-headless:/# DISPLAY=:1 /usr/bin/xfce4-session&
root@ubuntu-xfce-headless:/# x11vnc -usepw-forever-display:1 &
cat > start_session.sh
Xvfb:1 -extensionGLX -screen0 1024x780x24&
sleep 2
DISPLAY=:1 /usr/bin/xfce4-session &
sleep 2
x11vnc-usepw-forever -display:1 &
Press CTRL+C
chmod755 start_session.sh
When youstart yourDocker container youcan nowjust go.
./start_session.sh
See what your DockercontainerIP is.
root@ubuntu-xfce-headless:/# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu65536qdisc noqueue state UNKNOWN group default
link/loopback00:00:00:00:00:00brd00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft foreverpreferred_lft forever
inet6 ::1/128scope host
valid_lft foreverpreferred_lft forever
5: eth0: <BROADCAST,UP,LOWER_UP> mtu1500 qdisc noqueue state UP group default
link/ether 02:42:ac:11:00:01brdff:ff:ff:ff:ff:ff
inet 172.17.0.1/16scopeglobal eth0

5. valid_lft foreverpreferred_lft forever
inet6 fe80::42:acff:fe11:1/64 scope link
valid_lft foreverpreferred_lft forever
Install a VNC Viewer like tigervnc on your host OS and connect to 172.17.0.1:0 this will
default to port 5900 using display port 0
Everything now working !
I recommend that you go into yoursettings in XFCE and configure the appearance as i had no icons until i
selected Tango from the icons menu.
Ok now as promised you have your Ubuntu with XFCE running underDocker.
Now lets make this container into its own Image so i can make as many of these as i want the question is how.
Thats easy.
First detach from your
root@ubuntu-xfce-headless:/# exit
Go back to your Dockerfish terminal.
DockerFish> 2
List of DockerContainers
=========================
Command: /bin/bash ContainerId: 5073abe5f5c9 Image: ubuntu:latest Names: ["/ubuntu-xfce-headless"] Status: Exited(0)
About a minute ago
You can see that it has exited which you need to create a image from it.
DockerFish> 15
Enter Container to Image> ubuntu-xfce-headless
Enter your commit comment important> UbuntuXFCE Headless
Enter your Repositoryname> devel/headless-ubuntu-vnc
Image Commit Successfull
How do i check if it worked ?
DockerFish> 1
List of DockerImages
=====================
Created: 2015-06-26 13:14:16 Id: 97a9b89d37cf63b41e Image: ["devel/headless-ubuntu-vnc:latest"] Size: 501.381MB
VirtualSize: 680.944MB
Nowyou’ve createdyour image your free tocustomize it by makingmore containers andmakingtheminto images.
Enjoy !
Brian Hood