What is Docker? How To Install Docker on Ubuntu 14.04?

 

Docker is an open source container based software framework that automates the deployment of applications inside a software contains by providing an additional abstraction layer and automation of operating system level virtualization on Linux. Docker uses resource isolation features of the Linux kernel such as cgroups and kernel namespaces to allow independent "containers" to run within a single Linux instance, avoiding the overhead of starting and maintaining virtual machines.

How to Install:

Open Ubuntu Terminal Window and login as a root. Follow the below steps.

• Ensure all the packages are up to date.

            apt-get update 

• Now install Docker by installing the docker-io package.

           apt-get -y install docker.io

•  Link the path  

           ln -sf /usr/bin/docker.io /usr/local/bin/docker

• Fix the path settings.

          sed -i '$acomplete -F _docker docker' /etc/bash_completion.d/docker.io

• Optionally we can configure Docker to run when the server boots up.

            update-rc.d docker.io defaults

• Then we can start docker service

           service docker start

• Now download the docker container.

          docker pull ubuntu

• To set up a Ubuntu container with a bash shell 

          docker run -i -t ubuntu /bin/bash 

• To disconnect, or detach, from the shell without exiting use the escape sequence Ctrl-p + Ctrl-q. 
• To test whether docker is installed correctly. Just run the below command.

        docker run hello-world