What is Docker and how does it work

Docker is a Linux container platform. The brand is owned by Docker.Inc, a software company based in San Francisco. Free framework Moby Project is used for standardization and development. The platform itself is offered in two editions. Docker Community Edition is community supported and free. To use this edition, the user does not need to take any steps to obtain licenses. Docker Enterprise Edition is supported and distributed commercially. This edition provides many additional features for administration and security.

Docker is written in the Go programming language. It is a powerful compiled multithreaded language developed by Google. It is used to develop applications for multi-core processors and distributed systems.

Docker has several main components how to be a cloud architect.

Docker Client provides command line execution of the docker CLI and interaction with the Docker Daemon.

Docker Daemon or dockerd is an API and provides interoperability with other applications. The main functionality is implemented in the Docker API.

Containerd or docker-containerd is the container supervisor and is used in start, stop, and other commands to manage containers.

Shim or docker-containerd-shim implements a daemonless container model where a container can run independently of dockerd.

Runc or docker-runc makes containers work.

Docker uses CGroup, a Linux kernel engine that manages processor, network, memory, input and output computing resources, processes and process groups, and optimizes file system mounts. In fact, Docker is a container virtualization management layer that performs its functions through the Docker API.

How Docker is deployed depends on the version and type of distribution, as well as the underlying operating system. For example, for Linux, it makes sense to use a standard deployment script. Both Windows and macOS support Linux container platforms. If you need Docker on these operating systems, you need to use the appropriate distribution and command line tools.

Docker is a secure and resilient container platform. All images or containers run on the network, their IP addresses are NATed relative to the primary host, and only the ports that are needed are published. For secure communication with repositories, for example, Docker Hub can use certificates. Docker-based solutions are resilient using Swarm clustering. A large number of Docker health monitoring tools have been developed.

Notably, alternatives to the Docker platform, such as the free OpenShift platform supported by IBM and Red Hat, use similar technology solutions.

Learning Center "Networking Technologies" implements comprehensive training programs for containerization and management on the Docker platform.