Docker Example : Hello world ( Creating, push and pull an image and run as a container)

	Building app (Image > Container) Reference for this example	https://docs.docker.com/get-started/part2/#run-the-app
1	Create a directory	mkdir hello
2	Create these 3 files	Dockerfile         requirements.txt          app.py
3	Building image(app)	docker build -t friendlyhello .
4	Running App(container)	docker run -p 4000:80 friendlyhello  (4000 is the OS port and 80 is the port being used by the python in container)
5	Open webbrowser and type	http://192.168.99.100:4000
6	NOTE	192.168.99.100 is the default IP address of docker installed OS
7	View the container created	docker ps
	Share your image to Docker public registry
	Registry	A registry is a collection of repositories
	Repository	A repository is a collection of images
	Restart the environment	docker-machine restart default
	Refresh environment settings	eval $(docker-machine env default)
		docker login
	Associating a local image with a repository on a registry	username/repository:tag
	Tagging an image	docker tag friendlyhello sadakar/get-started:part1
		john is the username , get-started is the repository name and part1 is the tag
	Pushing the image	docker push sadakar/get-started:part1
		docker push sadakar/get-started:part2
	Pull and run the image from the remote repository	docker run -p 5000:80 sadakar/get-started:part2
		http://192.168.99.100:5000