Docker is an open platform for developing, shipping, and running applications. Docker is designed to deliver your applications faster. With Docker you can separate your applications from your infrastructure and treat your infrastructure like a managed application. Docker helps you ship code faster, test faster, deploy faster, and shorten the cycle between writing code and running code.

1. Docker Setup

2. Agenda
Install Docker
Understand Images and Containers
Find & Run Whalesay Image
Build your own image
Create a Docker Hub and Repository
Tag & push your image

3. Install Docker
Prerequisites
Update your apt sources
Prerequisites by Ubuntu Version
Install
Create a Docker Group

4. Prerequisites
Docker requires a 64-bit installation
Kernel version must 3.10 at minimum
To check kernel version
1.uname -r

5. Update your apt sources
1.Update package information
a. sudo apt-get update
2.Ensure that APT works with the https and that certificate
installed
a. sudo apt-get install apt-transport-https ca-certificates
3.Add new GPG key
a. sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys
58118E89F3A912897C070ADBF76221572C52609D
4.Open /etc/apt/sources.list.d/docker.list
5.If file not exist then create one and if exist then remove
the content.

6. 6.Add an entry
a. On Ubunut 14.04
i. deb https://apt.dockerproject.org/repo ubuntu-trusty main
b. On Ubuntu 16.04
i. deb https://apt.dockerproject.org/repo ubuntu-xenial main
7.Save and Close file
8.sudo apt-get update
9.Purge the old repo if exist
a. sudo apt-get purge lxc-docker
10.Verify the APT is pulling from the right repository
a. sudo apt-cache policy docker-engine
Continue...

7. Prerequisites by Ubuntu (14.04 and 16.04)Version
1.Update your package manager
a. sudo apt-get update
1.Install the recommended package
a. sudo apt-get install linux-image-extra-$(uname -r)
1.If you are installing on 14.04 (apparmor required)
a. sudo apt-get install apparmor

8. Install Docker
1.Update your package manager
a. sudo apt-get update
2.Install docker
a. sudo apt-get install docker-engine
3.Start the docker daemon
a. sudo service docker start
4.Verify docker is installed correctly
a. sudo docker run hello-world

9. Create a docker group
1. Create a docker group
a. sudo groupadd docker
2. Add your user to docker group
a. sudo usermod -aG docker $username
3. Log out and Log-in again
4. Verify your work by running docker without sudo
a. docker run hello-world
5. If it fails you will see
a. Cannot connect to the Docker daemon. Is ‘docker daemon’ running on
this host?
6. Check DOCKER_HOST environment variable is not set for your shell, if it is
then unset it.

10. Learn about Images and Containers
A container is a striped-to-basics version of a linux
operating system.
An image is software you load into a container.

11. Continue...
When you ran the command
▹Checked to see if you had the software image on local
▹If not exist then download it from the Docker Hub
▹Loaded the image into the container and ran it

12. Continue...
docker run docker/whalesay cowsay boo
It will download it from docker hub
docker images (to check existing images on your local
system).

13. Build your own image
▹Write a docker file
▹Build an Image from your docker file
▹Learn about your build process
▹Run your docker whale

14. Write your docker file
▹Create a text file (MyDocker)
▹Add a line to the file
▸FROM docker/whalesay:latest
▹The FROM keyword tells Docker which image your image
is based on
▹Now add a program to the image
▸RUN apt-get -y update && apt-get install -y fortunes
▹It will install fortunes in our image, fortunes has
commands and which is used to prints out.

15. Continue...
▹Once the image has the software it needs, you instruct
the software to run when the image is loaded.
▸CMD /usr/games/fortune -a|cowsay
▹Check your work, your file should look like this:
▸FROM docker/whalesay:latest
▸RUN apt-get -y update && apt-get install -y fortunes
▸CMD /usr/games/fortune -a | cowsay

16. Build an Image from docker file
▹Build an image by typing
▸docker build -t mine-image .
▹(Don’t forget .)
▹It will take few minute and image will be successfuly
built
▹The above command takes the Dockerfile in the
current directory, and buildds an image called mine-
image on your local machine.

17. Learn about build process
Sending build context to Docker daemon 2.048 KB
Step 1 : FROM docker/whalesay:latest (Since you
already have downloaded it from Docker hub so it will
not be downlod)
Step 2 : RUN apt-get -y update && apt-get install -y
fortunes
Step 3 : CMD /usr/games/fortune -a | cowsay

18. Run your new docker whale
docker images
docker run mine-image

19. Tag, push and pull your image
▹ List the images you currently have
▸ docker images
▹ Find the image id of your mine-image
▸In this case 33d1f3ae4bbd
▹ Currently repo name is mine-image but not the namespace. We need to
include the namespace for Docker Hub to associate it with your account.
▹ The name spce is the same as your Docket Hub account name.
▹ We need to rename the image to
▹ Use IMAGE_ID and the docker tag command to tag your docker-whale
▸ docker tag 33d1f3ae4bbd vendetta30/docker-whale:latest
▹ docker images
▹ docker login
▹ docker push
▸ docker push vendetta30/docker-whale

20. Create a dummy web example
RUN apt-get update
RUN apt-get upgrade -y
RUN apt-get install -y apache2
RUN service apache2 start
docker build -t webservice:test .
docker run --name WebService -p 85:80 -t -i webservice /bin/bash
docker start 5e6e8c290a8f
docker attach 5e6e8c290a8f

21. Reference
Installation:- https://docs.docker.com/engine/installation/linux/ubuntulinux/
https://www.jamescoyle.net/how-to/1503-create-your-first-docker-container
https://www.jamescoyle.net/how-to/1531-using-dockerfiles-to-build-new-
docker-images
http://www.tothenew.com/blog/docker-scenario-installing-and-using-
apache-web-server-in-docker-container/
http://lifeonubuntu.com/ubuntu-missing-add-apt-repository-command/
http://txt.fliglio.com/2013/11/creating-a-mysql-docker-container/
https://www.digitalocean.com/community/tutorials/docker-explained-how-
to-create-docker-containers-running-memcached