Docker 学习笔记-01：安装

• 安装
• • 前置准备
  • • 查看系统及内核版本
    • 卸载旧版本
    • 安装gcc相关
    • 安装yum-utils
    • 设置stable仓库地址（国内镜像源）
    • 更新yum软件包索引
  • 安装启动
  • • 安装docker ce
    • 启动docker
    • 查看docker version
    • 运行hello-world
  • 镜像加速
  • 卸载
• Docker VS Vitual Machine

参考：https://docs.docker.com/engine/install/centos/

[root@localhost ~]# uname -a
Linux localhost.localdomain 3.10.0-1160.62.1.el7.x86_64 #1 SMP Tue Apr 5 16:57:59 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
[root@localhost ~]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)

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

sudo yum -y install gcc
sudo yum -y install gcc-c++

sudo yum install -y yum-utils

sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

sudo yum makecache fast

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

sudo systemctl start docker

[root@localhost ~]# docker version
Client: Docker Engine - Community
 Version:           20.10.14
 API version:       1.41
 Go version:        go1.16.15
 Git commit:        a224086
 Built:             Thu Mar 24 01:49:57 2022
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.14
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.16.15
  Git commit:       87a90dc
  Built:            Thu Mar 24 01:48:24 2022
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.5.11
  GitCommit:        3df54a852345ae127d1fa3092b95168e4a88e2f8
 runc:
  Version:          1.0.3
  GitCommit:        v1.0.3-0-gf46b6ba
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker run hello-world

首次运行会默认拉取本地镜像，获取不到则会去镜像仓库拉取

[root@localhost ~]# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
2db29710123e: Pull complete 
Digest: sha256:10d7d58d5ebd2a652f4d93fdd86da8f265f5318c6a73cc5b6a9798ff6d2b2e67
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://mk9i2p1z.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

systemctl stop docker
yum remove docker-ce docker-ce-cli containerd.io
rm -rf /var/lib/docker
rm -rf /var/lib/containerd

• docker 有着比虚拟机更少的抽象层：由于docker不需要虚拟机实现硬件资源虚拟化，运行在docker容器上的程序直接使用的是宿主机的硬件资源，在资源利用率上有明显优势
• docker 利用宿主机的内核，无需加载OS内核：当新建一个 docker 容器时，不需要和虚拟机一样重新加载一个操作系统内核，进而避免引导、网络配置、系统相关库资源的过程，在创建过程耗时上也是具备明显优势