docker 安装部署

Docker 要求 CentOS 系统的内核版本高于 3.10 ，查看本页面的前提条件来验证你的CentOS 版本是否支持 Docker 。

通过 uname -r 命令查看你当前的内核版本
[root@runoob ~]# uname -r 

先更新yum源  yum update 

安装一些必要的系统工具：

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

添加软件源信息：
sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
这里会报错解决办法：
vi  /bin/yum-config-manager
修改头部注释#后面python 为python2解决

更新 yum 缓存：
sudo yum makecache fast

安装 Docker-ce：
sudo yum -y install docker-ce


启动 Docker 后台服务

sudo systemctl start docker

测试运行 hello-world

[root@runoob ~]# docker run hello-world

由于本地没有hello-world这个镜像，所以会下载一个hello-world的镜像，并在容器内运行。

看到Unable 不要慌正常
[root@hostuser dockerdir]# docker run hello-world
Unable to find image 'hello-world:latest' locally
docker: Error response from daemon: Get https://registry-1.docker.io/v2/library/hello-world/manifests/latest: Get https://auth.docker.io/token?scope=repository%3Alibrary%2Fhello-world%3Apull&service=registry.docker.io: net/http: request canceled (Client.Timeout exceeded while awaiting headers).
See 'docker run --help'.
[root@hostuser dockerdir]# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
1b930d010525: Pull complete
Digest: sha256:c3b4ada4687bbaa170745b3e4dd8ac3f194ca95b2d0518b417fb47e5879d9b5f
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/

　docker 卸载：

删除 Docker CE

执行以下命令来删除 Docker CE：

$ sudo yum remove docker-ce
$ sudo rm -rf /var/lib/docker

移除旧的版本：

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