What is docker? (bottom)

Chen Bucheng I 2022-06-24 07:17:42 阅读数:729

docker

Four .Docker What is it? ?

Docker Belong to Linux An encapsulation of a container , Provide easy to use container interface . It's the most popular Linux Container solution .

Docker Dependence of an application on that program , Package it in a file . Run this file , A virtual container will be generated . The program runs in this virtual container , It's like running on a real physical machine . With Docker, You don't have to worry about the environment .

On the whole ,Docker The interface is fairly simple , You can easily create and use containers , Put your application in a container . Containers can also be version managed 、 Copy 、 Share 、 modify , It's like managing common code .

5、 ... and .Docker Use of

Docker Main purpose of , At present, there are three categories . 1. Provide a one-time environment . such as , Test others' software locally 、 Provide the environment for unit testing and building during continuous integration .

2. Provide flexible cloud services . because Docker The container can be opened and closed , It is very suitable for dynamic expansion and reduction .

3. Build a microservice Architecture . Through multiple containers , One machine can run multiple services , So we can simulate the microservice architecture on our own .

6、 ... and .Docker The composition of

Docker The three concepts of : structure 、 transport 、 function

It's like Docker The same icon as , It carries a lot of containers . We can think of the host as this whale , Consider isolated containers as containers , Each container contains its own application . The whale may represent the founder Solomon Hykes The vision of the Internet in my eyes , It's like 20 century 50 In the s, containers overturned the global mode of material transportation , It will revolutionize the way information is transported , Let the goods on the Internet train 、 automobile 、 There is no obstruction between ships .

Docker Be similar to cs structure , A daemon serves as the server , Command as client , Users take client To operate the server .

7、 ... and .Docker The components of

Mirror image (Image) It's like a virtual machine , It's the same as a virtual machine , It's just that the components are different . Simply put, you must have an image to start a container

Containers (Container) docker It's the container that runs the business , It's like running a kvm Virtual machines are the same . A container is actually an instance created from an image . We can add, delete, modify and query the container , Containers are also isolated from each other . The biggest difference between virtual machines and virtual machines is that one is virtual and the other is isolated .

Warehouse (Repository) Like Baidu network disk , We need a warehouse to store images ,Docker Official provides public image warehouse ; From the perspective of security and efficiency, we can also deploy private environments Registry Or is it Harbor.

8、 ... and .Docker The difference between and virtualization

characteristic

Containers

virtual machine

Starting time

Second level

Minutes of class

The hard disk to use ( Image size )

It's usually MB

It's usually GB

performance

Close to the original

Extra performance

System support

A single machine supports thousands of containers

Generally dozens of them

Nine .Docker Advantages and disadvantages

advantage : Fast start Light weight , Each mirror is very small Light isolation , Each container is isolated , Mutual indifference

shortcoming : Container isolation is not as strong as virtualization share linux kernel , There are congenital defects in safety selinux It's hard to control Monitoring containers and container troubleshooting is a challenge

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