1 Installation Instructions for Ubuntu:
The simplest way to get docker, other than using the pre-built application image, is to go with a 64-bit Ubuntu 14.04
2.Update your Ubuntu
$ sudo apt-get update
$ sudo apt-get -y upgrade
3.Make sure aufs support is available:
$ sudo apt-get install linux-image-extra-`uname -r`
4.Add docker repository key to apt-key for package verification:
$ sudo apt-key adv --keyserver hkp://pgp.mit.edu:80 –recv-keys 58118E89F3A912897C070ADBF76221572C52609D
5.Add the docker repository to Apt sources:
$ echo "deb https://apt.dockerproject.org/repo ubuntu-trusty main" | sudo tee /etc/apt/sources.list.d/docker.list
6.Update the repository with the new addition:
$ sudo apt-get update
7. Finally, download and install docker:
$ sudo apt-get install docker-engine
8 Ubuntu's default firewall (UFW: Uncomplicated Firewall) denies all forwarding traffic by default, which is needed by docker.
Enable forwarding with UFW:
Edit UFW configuration using the nano text editor.
$ sudo nano /etc/default/ufw
Scroll down and find the line beginning with DEFAULTFORWARDPOLICY.
Replace:
DEFAULT_FORWARD_POLICY="DROP"
With:
DEFAULT_FORWARD_POLICY="ACCEPT"
save and close the editor.
9.Start the Docker service.
$ sudo service docker start