Docker three. Basic concepts

Docker Basic Concepts

A. Mirror

1.1 What is mirroring

The Docker image is a read-only template that is used to create containers. like a virtual machine image, it can be understood as a read-only template for the Docker engine that contains the file system.

For example, a mirror has a full centos operating environment, which can be called a centos image. The image is installed with Nginx, which can be called an nginx image.

1.2 Docker Image

Docker provides a very simple mechanism for creating images, or modifying existing ones, and you can share your created images directly with others. For example, your team's project requires a unified development environment, and if everyone is configured according to the same settings, it's certainly time consuming, with Docker, just configuring the good one container, and then sharing the configured container with your friends can be used directly.

two. Container

2.1 What is a container

Docker uses containers to run applications, containers like a lightweight sandbox,andDocker uses containers to run and isolate applications.

What 2.2 containers can do

A container is a running instance created from a mirror that can be started, started, stopped, and deleted. Each container is isolated from each other, using port communication to ensure container security.

A container can be seen as a simple Linux environment (including root, permissions, process space, user space, and network space) and applications running in it.

Note: The mirror is read-only, and the container starts by creating a writable layer as the topmost

three. Docker warehouse

3.1 What is a Docker warehouse

The warehouse is the place where the image files are stored. Warehouses are divided into private warehouses and shared warehouses. At present, the largest public warehouse is the Docker Hub, which stores a large amount of images for users to download. The public warehouse in China includes Docker Pool , which can provide the document download and access.

If your image doesn't want to be shared online,Docker also allows users to create a private repository on their local network that can only be accessed on their own.

Docker three. Basic concepts