01-docker Introduction and Installation

What is the Docker
Docker is an open source project, was born in early 2013, it was initially an amateur project internal dotCloud company, which is based on the company launched go google language. Project later joined the linux foundation, apache2.0 comply with the agreement, the project code is maintained on github.
docker since the open source widespread attention and discussion that dotCloud companies were later renamed docker inc. Redhat has concentrated its support docker in the RHEL6.5, google also paas its products are widely used.

docker project's goal is to achieve a lightweight operating system virtualization solution. Linux is based docker container (LXC) technology.

docker architecture
talk about docker components
Docker daemon (docker daemon)
docker daemon is running a host (docker_host) background processes. Docker can communicate with the client.

Client (client docker)
docker docker client is a user interface that accepts user commands and configuration identifier, and to communicate with the docker daemon. docker build and so
are related commands docker

Images (docker Mirror)
docker image is a read-only template that contains the instructions for creating a docker container. It and system installation CD --- a bit like using a system installation disc to install
the system, the same token, the mirror can run the program using the docker docker in the mirror.

Container (container)
container is a running instance be mirrored. Relationship between the mirror and the container somewhat similar to the object-oriented, and the relationship of classes of image. You may start and stop commands by the docker api or cli, move, delete container.

Registry
Docker Registry is a mirror image of centralized storage and distribution services. After constructing docker mirror, it can be run on the current host. But if you want to run this image on other machines, you need to go hand copy. At this point you can be avoided by means of docker registry manually copied image.
Registry may comprise a plurality of docker docker depot, repository may comprise a plurality of mirrors each of tags, each corresponding to a docker mirror. This is somewhat similar to a warehouse with maven, if compared to the docker Registry maven repository, then docker warehouse understandable path for a jar package, and label image can be understood as the version number of a jar.
docker registry docker registry can be divided into public and private docker registry. The most commonly used docker Registry than the official docker hub, which is the default docker Registry. docker on the hub to store a large number of excellent image, use the command docker to download and use.