you can add the Docker official repository or the Docker mirror provided by Alibaba Cloud to your CentOS 7 system to install Docker. Below are the steps to do so:
$ sudo yum install -y yum-utils device-mapper-persistent-data lvm2

Method 1: Using Docker's Official Repository ,Uninstall Older Versions (if any)

sudo yum remove docker \
                docker-client \
                docker-client-latest \
                docker-common \
                docker-latest \
                docker-latest-logrotate \
                docker-logrotate \
                docker-engine
                
Install Required Packages:

sudo yum install -y yum-utils
Set Up the Repository:

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

sudo yum install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
Start and Enable Docker Service:

sudo systemctl start docker
sudo systemctl enable docker

=======================================================
Method 2: Using Docker Mirror from Alibaba Cloud (Alibaba Cloud Mirror)
Uninstall Older Versions (if any): (Same as above)

sudo yum remove docker \
                docker-client \
                docker-client-latest \
                docker-common \
                docker-latest \
                docker-latest-logrotate \
                docker-logrotate \
                docker-engine
Install Required Packages:(Same as above)

sudo yum install -y yum-utils
Configure the Alibaba Cloud Docker Repository:

sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
Install Docker CE:(Same as above)

sudo yum install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
Start and Enable Docker Service: (Same as above)

sudo systemctl start docker
sudo systemctl enable docker
Verifying Installation:
To verify that Docker is installed correctly, run:

docker --version
This should display the version of Docker installed on your system. If you see the version, then Docker has been successfully installed.

Additional Configuration (Optional):
You might want to add your user to the docker group so you can run Docker commands without using sudo:

sudo usermod -aG docker $USER # Replace $USER with your actual username if you are logged in as root or another user. 
newgrp docker # Or log out and log back in to apply the changes. 
This will add your user to the docker group and allow you to run Docker commands without sudo.

Choose either Method 1 or Method 2 based on your preference for the Docker repository source. If you are located in China or have a strong connection to Alibaba Cloud, using the Alibaba Cloud mirror can be faster and more reliable due to its geographical proximity and optimized network paths. Otherwise, using the official Docker repository is also a good choice for global users

可能会出现兼容性问题 container.io 需要安装较低版本

推荐在 CentOS 7 上安装的版本
由于 CentOS 7 内核版本较老，建议安装较旧的稳定版本：
# 安装兼容性较好的 Docker 24.0.x 版本
sudo yum install docker-ce-24.0.7-1.el7 docker-ce-cli-24.0.7-1.el7 containerd.io

# 或者安装 23.0.x 版本
sudo yum install docker-ce-23.0.6-1.el7 docker-ce-cli-23.0.6-1.el7 containerd.io

# 查看可用的 containerd.io 版本
yum list containerd.io --showduplicates

# 安装较旧但兼容的版本（推荐）
sudo yum install -y containerd.io-1.6.28-3.1.el7.x86_64

# 然后再安装 docker
sudo yum install -y docker-ce docker-ce-cli

镜像加速器配置

您可以通过修改daemon配置文件/etc/docker/daemon.json来使用加速器

阿里云加速已经停止运行，改为清华大学或者搜狐的镜像源
sudo mkdir -p /etc/docker

sudo tee /etc/docker/daemon.json <<-'EOF'
{
    "registry-mirrors": [
        "https://mirrors.tuna.tsinghua.edu.cn",
        "http://mirrors.sohu.com",
        "https://ccr.ccs.tencentyun.com",
        "https://mirror.iscas.ac.cn/"
        "https://docker.awsl9527.cn"
    ]
}

EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

# 查看所有可用的 Docker CE 版本
yum list docker-ce --showduplicates | sort -r

# 或者使用更详细的查询
yum --showduplicates list docker-ce   

=============================================
# 备份原有仓库配置
sudo mv /etc/yum.repos.d/docker-ce.repo /etc/yum.repos.d/docker-ce.repo.bak

# 使用阿里云镜像源
sudo wget -O /etc/yum.repos.d/docker-ce.repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

# 清理并重建缓存
sudo yum clean all
sudo yum makecache

# 尝试安装
sudo yum install -y docker-ce docker-ce-cli containerd.io

# 安装经过验证的兼容版本组合
sudo yum install -y docker-ce-24.0.7-1.el7 \
                   docker-ce-cli-24.0.7-1.el7 \
                   containerd.io-1.6.21-3.1.el7

sudo systemctl restart docker

验证是否安装成功

docker images 

docker ps 

docker run hello-world

================================================

在CentOS 7上卸载Docker的步骤如下：

1. 停止Docker服务

bash

sudo systemctl stop docker
sudo systemctl stop docker.socket

2. 卸载Docker软件包

如果使用yum安装的Docker：

bash

sudo yum remove docker \
               docker-client \
               docker-client-latest \
               docker-common \
               docker-latest \
               docker-latest-logrotate \
               docker-logrotate \
               docker-engine

如果使用官方Docker仓库安装：

bash

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

3. 删除Docker相关文件和目录

bash

# 删除Docker工作目录
sudo rm -rf /var/lib/docker
sudo rm -rf /var/lib/containerd

# 删除Docker配置文件
sudo rm -rf /etc/docker

# 删除Docker相关文件
sudo rm -f /etc/systemd/system/docker.service
sudo rm -f /etc/systemd/system/docker.socket

4. 删除Docker用户组（可选）

bash

# 查看是否还有用户在使用docker组
sudo grep docker /etc/group

# 如果没有用户使用，可以删除docker组
sudo groupdel docker

5. 清理依赖包（可选）

bash

# 自动移除不再需要的依赖包
sudo yum autoremove

6. 清理yum缓存（可选）

bash

sudo yum clean all

7. 重新加载systemd（如果删除了服务文件）

bash

sudo systemctl daemon-reload

验证卸载

bash

# 检查Docker是否已卸载
docker --version

# 检查Docker服务状态
systemctl status docker

如果以上命令显示"Docker命令未找到"或"服务不存在"，说明Docker已成功卸载。

注意事项

• 卸载前请确保已备份重要的Docker镜像和容器数据

• /var/lib/docker 目录包含所有Docker数据，删除后将无法恢复

• 如果打算重新安装Docker，可以保留配置文件和数据目录