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This article introduces the relevant knowledge of "what are the basic knowledge points of docker". In the operation of actual cases, many people will encounter such a dilemma. Next, let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

I. Overview of docker

1. Why did you propose docker?

When you put an application project online, you need to configure a complex environment on the server, which is too time-consuming and laborious, and deploying different applications on the same server may lead to conflicts.

two。 What is the difference between traditional and current application deployment?

a. Tradition: the developer develops the code package and gives it directly to the operation and maintenance personnel, then the operation and maintenance personnel deploy the running environment, and the application is launched.

b. Now: development, packaging and deployment are online, and a set of processes are completed.

What are the advantages of 3.docker?

A.docker isolates multiple applications through containers and runs on the same server to avoid conflicts caused by different applications deployed on the same server.

B.docker can also use the isolation mechanism to maximize the resources of the server.

The related website of 4.docker?

a. Official website

b. Official document

c. Image warehouse

Second, the introduction of containerization and virtualization technology. Virtualization technology

Download the native image file of the system, usually a few gigabytes, and then install it in VM, which is very clumsy

b. Containerization technology

Download images (usually only a few megabytes or hundreds of megabytes) through docker image repositories or Aliyun image repositories. Containers are created through images, and the containers are isolated from each other, which is small and easy to use.

c. Comparison of advantages and disadvantages of two technologies

Virtualization technology: it can simulate a computer well and completely, but it takes up more resources of the host host, many installation and deployment steps, troublesome operation and slow start-up.

Containerization technology: it does not simulate a complete operating system, the application in the container runs directly on the host host, and the container does not have its own kernel or virtual hardware. Each container is isolated from each other and has its own file system that does not affect each other.

III. The role of docker

a. Faster delivery and deployment of applications

Docker package image release test, run with one click

b. Faster upgrade and expansion

c. Simpler system operation and maintenance

d. More efficient use of computer resources

Multiple container instances can be run on a single physical machine, thus ensuring full utilization of server resources and minimizing performance

IV. Docker installation

Address: https://blog.csdn.net/qq_44316726/article/details/108557361

Fifth, the operation process and underlying principle of run 1. When we use the docker run command to create a container, it runs as follows

A.docker will search the local computer for the image to determine whether it exists.

b. If the image is found on the local machine, it is used to create a container. Otherwise, proceed to the next step

c. Go to the docker Hub official website to download the image. If you find the image, download it locally and use it to create a container. If the image is not found, an error is returned.

two。 Underlying principle

Docker is a Client-Server-structured system, the docker daemon runs on the host, and the consumer accesses the process from the client through Socket. After receiving the instruction from docker-Client, docker-Server will execute the instruction.

6. The common command of docker a. Help command

Docker version # displays the version information of docker

Docker info # displays detailed system details, including the number of images and containers

Docker command-- help # displays the details of the command and how to use it

b. Mirror command

View the image:

Docker images # View the image on the local host

# Parameter description-a lists all images-Q shows only the id of the image

Search image

Docker search image name

# Parameter introduction-f filtering option

Example: docker search-- filter=SIZE=5000 mysql

Download the image

Docker pull image name # download the latest version of the image by default

Docker pull image name: version # download the specified version

Delete Mirror

Docker rmi-f image id # Delete a mirror

Docker rmi-f image id image id # delete multiple images

Docker rmi-f $(docker image-aq) # delete all local mirrors

c. Container command

Note: only when we have a mirror image can we use common containers.

Create a new container and start it

Docker run [option] Image name

# option interpretation

-- name='centos01' # specifies the name of the container, which is used to distinguish different containers created by the same image

-d # running in the background

-it # runs interactively and goes to the container to view the content

-p # specify the port of the container

-p ip: host port: container port

-p host port: container port

-p container port

Container port

-P # randomly designated port

List the containers running

Docker ps [options] # list the containers that are running

Option interpretation

-a # list the containers that are running + containers that have been running in history

-n = number # lists the most recent process containers

-Q # displays only the container number

Exit the container

Exit # exit and stop the container

Ctrl+q+p # exit does not stop the container

Delete Container

Docker rm Container id # Deletes the specified container, but cannot delete the container that is running

Docker rm-f Container id # removes a running container

Docker rm-f $(docker ps-aq) # Delete all containers

Start stop container

Docker start Container id

Docker restart Container id

Docker stop Container id

Docker kill Container id # Force stop Container

7. The advanced order of docker a. View the log

Docker logs-- tf-- tail log shows the number of containers id

b. View the number of processes in the container

Docker top Container id

c. View mirrored metadata

Docker inspect Container id

d. Enter the background to run

Docker exec-it container id / bin/bash # after entering the container, it will open a new terminal and operate in it

After docker attach container id # enters the container, it will not open a new terminal, but will directly use the running terminal.

e. Copy the files in the container on the physical host

Docker cp container id: the path within the container. The target path of the CPM.

This is the end of the content of "what are the basic knowledge points of docker". Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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