Docker Architecture

Docker Architecture provides details about all major components belongs to docker platform, also explain how each components works together to fulfill requirements. Also we will see, how the actions will takes once run the commands in Docker Client (CLI).

Docker is having below major components:

• Docker Client :  is used to instruct daemon through commands.

• Docker Host : host many components for docker such as Docker daemon, Images, containers and data volumes

Note: docker deamon is a type of long-running program known as daemon process which actually performs the tasks.

• Docker Registry : Docker registry is cloud based storage space where docker images could be stored. Docker provides public access to docker cloud and docker hub. This registry contains pre-build docker images in public registry that we can pulled and use it for our applications.

                    Also we can create our own private registry where we can store our own images and make public if we want to contribute to the community.

• Docker Images : Docker image is a read-only template that can be used to initiate containers. Docker image could contain an OS, a Web Server, a Web Application. Docker image having many read-only layers.

Note: Docker image is created after execution of Dockerfile which is a simple text file contains commands in sequence. Docker image is having layer bases on commands in Dockerfile, more command means more layer in the docker image.

• Docker container : Docker container is a type of process that uses Docker image and runs. Once we run docker image, it creates writable layer, top of Docker image's read-only layers. Like a process, containers can be run, started, stopped, moved and deleted. Each container running on host are isolated with other containers until we provide connectivity (expose interface to communicate).