Docker from understanding practice to underlying principle (3)｜Docker installation and configuration in Centos7 environment

foreword

Well, the blogger here will first post some columns full of dry goods!

The first is a summary of bloggers’ high-quality blogs. The blogs in this column are all the bloggers’ most thoughtful writing. They are full of dry goods. I hope they will be helpful to everyone.

• Summary of high-quality blogs

Then there is the blogger's most time-consuming column recently, "Docker From Understanding Practice to Underlying Principles", I hope everyone will pay more attention!

• Docker from the realization of practice to the underlying principle

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Chapter 3 - Introduction to docker

docker official website

• https://www.docker.com

docker installation

The blogger uses the centos7 system as a demonstration.

check your system

Check system and version.

cat /etc/*release*

(base) [yufc@ALiCentos7:~]$ cat /etc/*release*
CentOS Linux release 7.9.2009 (Core)
Derived from Red Hat Enterprise Linux 7.9 (Source)
cat: /etc/lsb-release.d: Is a directory
NAME="CentOS Linux"
VERSION="7 (Core)"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="7"
PRETTY_NAME="CentOS Linux 7 (Core)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:7"
HOME_URL="https://www.centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-7"
CENTOS_MANTISBT_PROJECT_VERSION="7"
REDHAT_SUPPORT_PRODUCT="centos"
REDHAT_SUPPORT_PRODUCT_VERSION="7"

CentOS Linux release 7.9.2009 (Core)
CentOS Linux release 7.9.2009 (Core)
cpe:/o:centos:centos:7
(base) [yufc@ALiCentos7:~]$

The blogger here is the Centos7 version of Linux.

Check the cpu architecture.

uname -a

(base) [yufc@ALiCentos7:~]$ uname -a
Linux ALiCentos7 3.10.0-1160.88.1.el7.x86_64 #1 SMP Tue Mar 7 15:41:52 UTC 2023 x86_64 GNU/Linux
(base) [yufc@ALiCentos7:~]$

uninstall old version

The command is as follows.

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

Uninstall the previous version

sudo yum remove docker-ce docker-ce-cli containerd.io docker- buildx-plugin docker-compose-plugin docker-ce-rootless-extras # 删除机器上的包

sudo rm -rf /var/lib/docker
sudo rm -rf /var/lib/containerd
sudo rm -rf /data/var/lib/docker
sudo rm -rf /etc/docker/daemon.json # 这是修改后的配置，根据实际情况进行设置

Configure the repository

This is the repository on our machine.

(base) [yufc@ALiCentos7:~]$ ll /etc/yum.repos.d/
total 32
-rw-r--r-- 1 root root  675 Apr 27 23:11 CentOS-Base.repo
-rw-r--r-- 1 root root  998 Dec 11  2018 CentOS-SCLo-scl.repo
-rw-r--r-- 1 root root  971 Oct 29  2018 CentOS-SCLo-scl-rh.repo
-rw-r--r-- 1 root root  230 Apr 27 23:11 epel.repo
-rw-r--r-- 1 root root 1358 Sep  5  2021 epel.repo.rpmnew
-rw-r--r-- 1 root root 1457 Sep  5  2021 epel-testing.repo
-rw-r--r-- 1 root root 1838 Apr 27  2017 mysql-community.repo
-rw-r--r-- 1 root root 1885 Apr 27  2017 mysql-community-source.repo
(base) [yufc@ALiCentos7:~]$

We need to install the warehouse given by docker into it

sudo yum install -y yum-utils # 安装最新的yum-utils

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

At this time, there is one more docker-ce.repowarehouse inside.

Configure to use domestic sources

sudo sed -i 's@//download.docker.com@//mirrors.ustc.edu.cn/docker-ce@g' /etc/yum.repos.d/docker-ce.repo

install latest version

sudo yum install -y docker-ce docker-ce-cli containerd.io docker- buildx-plugin docker-compose-plugin

start docker

#配置加载
sudo systemctl daemon-reload #启动服务
sudo systemctl start docker #开启启动
sudo systemctl enable docker #查看服务状态
sudo systemctl status docker # 查看状态

At this time, docker is in the started state!

View docker version

sudo docker version

sudo docker info

Docker installation practical experience

docker image source modification

cd /etc/docker/ # 进入docker配置的目录

touch daemon.json # 创建 daemon.json

vim daemon.json # 编辑这个文件

Type these in.

{
    
    
        "registry-mirrors": ["https://docker.mirrors.ustc.edu.cn/"]
}

systemctl daemon-reload # 加载配置
systemctl restart docker # 重启docker服务

docker data directory adjustment

The default installation directory of Docker is /var/lib/docker, which will store many, many images, so we need to consider the space of this directory when installing. There are three solutions.

1. It will /var/lib/dockerbe mounted to a large disk. Generally, we can control the mount directory. Cloud vendors like Tencent Cloud provide mount options when installing K8s nodes. You can directly mount this directory in the past
2. Mount a large disk before installation, and then create a soft link to it /var/lib/docker, so that it will be automatically installed to our disk with a relatively large space
3. After installing docker, we found that we forgot to configure this directory. We need to modify the configuration file of docker.

#假定我们磁盘的大的目录为 /data mkdir -p /data/var/lib/docker # 编辑配置文件
vi /etc/docker/daemon.json
# 输入下面的json
{
    
    
	"data-root": "/data/var/lib/docker" 
}
# 加载配置
sudo systemctl daemon-reload
sudo systemctl restart docker # 重启docker
sudo systemctl status docker # 查看 docker 状态