Now that AI intelligence is in full swing, if you don't know how to click ChatGPT, you will always feel a little behind. I just reviewed Docker recently, and here I try to generate an article about Docker through ChatGPT. Let's see the effect.

1. What is Docker

Docker is a containerization technology that encapsulates applications and their dependencies in a virtual container so that they can be easily deployed and run on any computer. Docker uses operating system-level virtualization technology, also known as containerization technology, to allow an application and its dependencies to be packaged as a self-contained, portable container that can run on any operating system that supports Docker, including Linux, Windows, and Mac OS.

A Docker container is a lightweight, portable virtualization technology that runs on top of a host operating system. This makes Docker containers lighter, more flexible, and more portable than traditional virtual machines because they don't require an additional operating system. Docker containers can also share resources on the host operating system, meaning multiple containers can run on the same computer without interfering with each other.

Docker can use Docker images to create containers. A Docker image is a static file that contains all the files and dependencies needed to run an application. Docker images can be downloaded from Docker Hub or other Docker image repositories, or built manually.

Docker also provides a set of command-line tools that allow users to create, manage and run containers. These tools make using and managing Docker containers easy, reliable, and repeatable. Docker containers can be deployed to local computers, cloud computing platforms, or clusters. They can also interact with other containers and applications to enable more powerful applications and services.

In short, Docker is a powerful containerization technology that allows developers to easily create, deploy and run applications, while also providing tools for managing and monitoring containers, making the use and management of containers simple, reliable and repeatable .

2. Why use docker

Using Docker has several advantages:

Simplified application deployment: Docker containers can encapsulate an application and its dependencies in a single container, which makes application deployment simple, reliable, and repeatable. Containers can run on any operating system that supports Docker and require no dependencies to be installed and configured.
Improved application portability: Since Docker containers are independent of the host OS, they can run on any OS that supports Docker. This makes containers portable across different environments, such as on a local computer, in a cloud computing platform, or in a cluster.
Better resource utilization: Docker containers are lightweight virtualization technology, they can share resources on the host operating system, which means that multiple containers can run on the same computer without interfering with each other. This resource utilization method can improve the utilization rate of the computer and reduce the waste of resources.
Better application isolation: Since Docker containers are self-contained, they can isolate applications and their dependencies, which means that an application in one container cannot affect an application in another container. This isolation improves application stability and reliability.
Better development environment management: Docker containers can be used to create and manage development environments, which can help developers build and test applications more easily. Since Docker containers are portable, they can be easily ported across development, test, and production environments.

To sum up, using Docker can make application deployment, porting, and management easier, more reliable, and more repeatable. It also improves resource utilization, application isolation, and development environment management capabilities, enabling developers to develop and deploy more efficiently.

3. What is the difference between Docker deployment and traditional virtual machine deployment?

There are several differences between Docker deployments and traditional virtual machine deployments:

Resource utilization: Traditional virtual machines need to allocate independent operating system and hardware resources for each virtual machine, which will cause waste of resources. In contrast, Docker utilizes the operating system and hardware resources of the host machine to run multiple containers in a shared operating system, thereby improving resource utilization.
Deployment speed: Traditional virtual machines need to install an independent operating system and other necessary software, and this process usually takes a few minutes or longer. Docker containers, on the other hand, can be started in seconds because they only need the software and dependencies needed to run on the host machine, and do not need to start the entire operating system like a virtual machine.
Deployment complexity: The deployment and management of traditional virtual machines is relatively complex, and many aspects need to be considered, such as network configuration, storage management, security, and so on. The deployment and management of Docker containers is relatively simple, because they use the same base image and shared operating system, so they can be easily deployed, updated and expanded.
Environmental isolation: Virtual machines provide hardware-level isolation through hardware virtualization technology, while Docker containers use kernel-level isolation technology, that is, Linux containers. This isolation technique can provide better security and resource isolation between containers, but they still share the same operating system kernel.

In short, compared with traditional virtual machines, Docker containers have better resource utilization, faster deployment speed, simpler deployment complexity, and better environment isolation, which makes Docker a better deployment choice in many scenarios.

4. How to install docker on centos

To install Docker on CentOS, follow these steps:

Update system packages:

sudo yum update

Install the required packages:

sudo yum install -y yum-utils device-mapper-persistent-data lvm2

Add Docker warehouse source:

sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

Install Docker:

sudo yum install docker-ce docker-ce-cli containerd.io

Start the Docker service:

sudo systemctl start docker

Set Docker to start on boot:

sudo systemctl enable docker

Confirm that Docker was installed successfully:

sudo docker version

Now that Docker has been successfully installed on CentOS, you can use the docker command to manage containers and images.

5. Common commands of docker

The following are some commonly used commands for Docker:

docker run: start a new container
docker start: start a stopped container
docker stop: Stop a running container
docker restart: restart a container
docker kill: force stop a container
docker rm: delete one or more containers
docker ps: list all running containers
docker ps -a: List all containers, including stopped ones
docker images: list all mirrors
docker rmi: delete one or more mirrors
docker build: Build an image from a Dockerfile
docker exec: Execute a command in a running container
docker logs: view the log output of the container
docker port: View the port mapping of the container
docker network ls: list all networks
docker network create: create a new network
docker network connect: connect a container to a network
docker network disconnect: disconnect the container from a network

These commands are only a small part of the Docker commands, there are many other commands and options that can be used. You can docker --helpview the full Docker help documentation by typing

6. Docker installs JDK

To install JDK in Docker, follow these steps:

Select the JDK version to be installed and specify the base image in the Dockerfile. For example, if you choose the Oracle JDK 11 version, you can choose the official base image oraclelinux:8-slimand add the following code to the Dockerfile:
```
FROM oraclelinux:8-slim
```
Download the JDK installation package and copy it into the Docker container. ADDIt can be done by using or COPYcommand in Dockerfile . For example, to download the JDK 11 installation package and copy it to a Docker container, you can add the following code to the Dockerfile:
```
ADD jdk-11.0.11_linux-x64_bin.tar.gz /usr/local
```
Please note that it is assumed that the JDK installation package has been downloaded locally and is located in the directory where the current Dockerfile is located. If the JDK installation package is located on a remote server, you need to use a tool such wgetas or curlto download it, and specify the download path in the Dockerfile.
Set environment variables so that applications in the container can find the JDK. ENVIt can be done using command in Dockerfile . For example, to set the JAVA_HOME and PATH environment variables of JDK 11, you can add the following code to the Dockerfile:
```
ENV JAVA_HOME=/usr/local/jdk-11.0.11 ENV PATH=$PATH:$JAVA_HOME/bin
```
Build the Docker image. Execute the following command in the directory where the Dockerfile is located:
```
docker build -t myjdk:11 .
```
Here it is assumed that the name of the Dockerfile is Dockerfile, the name of the built image is myjdk, and the version is 11.
Run the container and verify that the JDK was installed successfully. A Bash shell can be started in a new container with the following command:
```
docker run -it myjdk:11 /bin/bash
```
In the Bash shell, you can run the following command to verify that the JDK was successfully installed:
```
java -version
```
If the installation was successful, you should be able to see the output of the JDK version information.

The above are the basic steps to install JDK in Docker. The steps can be adjusted and optimized as needed.

7. Docker installs MySQL

To install MySQL in Docker, follow these steps:

Select the MySQL version to be installed and specify the base image in the Dockerfile. For example, if you choose the MySQL 8 version, you can choose the official basic image mysql:8and add the following code to the Dockerfile:
```
FROM mysql:8
```
Set the initial password for the root user for MySQL. ENVThis can be done by setting environment variables using commands in the Dockerfile MYSQL_ROOT_PASSWORD. For example, to set the initial password of the root user to mysecretpassword, you can add the following code to the Dockerfile:
```
ENV MYSQL_ROOT_PASSWORD=mysecretpassword
```
Build the Docker image. Execute the following command in the directory where the Dockerfile is located:
```
docker build -t mymysql:8 .
```
Here it is assumed that the name of the Dockerfile is Dockerfile, the name of the built image is mymysql, and the version is 8.
Run the container and verify that MySQL installed successfully. The MySQL service can be started in a new container with the following command:
```
docker run -d --name mymysql -p 3306:3306 mymysql:8
```
Assume here that the container name is mymysql, and map port 3306 in the container to port 3306 of the host.
Use the MySQL client to connect to the MySQL service in the container. You can install the MySQL client on the host machine and connect to the MySQL service in the container with the following command:
```
mysql -h 127.0.0.1 -u root -p
```
Enter the initial password of the root user to log in to the MySQL service.

The above are the basic steps to install MySQL in Docker. The steps can be adjusted and optimized as needed.

8. Docker installs Redis

To install Redis in Docker, follow these steps:

Specify the base image in the Dockerfile. You can choose the official base image redis:6and add the following code to the Dockerfile:
```
FROM redis:6
```
Build the Docker image. Execute the following command in the directory where the Dockerfile is located:
```
docker build -t myredis:6 .
```
Here it is assumed that the name of the Dockerfile is Dockerfile, the name of the built image is myredis, and the version is 6.
Run the container and start the Redis service. The Redis service can be started in a new container with the following command:
```
docker run -d --name myredis -p 6379:6379 myredis:6
```
Assume here that the container name is myredis, and map port 6379 in the container to port 6379 of the host.
Use the Redis client to connect to the Redis service in the container. You can install the Redis client on the host machine and use the following command to connect to the Redis service in the container:
```
redis-cli -h 127.0.0.1 -p 6379
```
It is assumed here that the Redis client has been installed on the host, and port 6379 in the container is mapped to port 6379 of the host.

The above are the basic steps to install Redis in Docker. The steps can be adjusted and optimized as needed.

9. Summary

At the end of the writing, the more I wrote, the more panicked I became. But ChatGPT is good, after all, the existing models are just auxiliary tools. I also tried to install it according to the command, but it didn't work. So it still has to be judged manually. With the blessing of ChatGPT, it has to be said that learning some new technologies has become much easier, but after all, some people will be eliminated and some people will be successful.

ChatGPT generates an article: About Docker