一、docker安装笔记

摘要：出于安全考虑，一般系统上不会直接使用用户。因此，更好地做法是将需要使用的用户加入用户组。建立组将当前用户加入组退出当前终端并重新登录，进行如下测试。无需使用管理员权限测试运行运行列出镜像仓库名标签镜像创建时间占用空间

1.1 查看当前linux内核版本

uname -r #linux内核要求3.10及以上

1.2 更行yum源

sudo yum update 

1.3 如果安装过旧版本的话，卸载旧版本

sudo yum remove docker  docker-common docker-selinux docker-engine

1.4 安装需要的软件包， yum-util 提供yum-config-manager功能，另外两个是devicemapper驱动依赖的

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

1.5 由于国内网络问题,建议使用国内源,添加yum软件源

sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo  #阿里云镜像源

已加载插件：fastestmirror, langpacks
adding repo from: http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
grabbing file http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo to /etc/yum.repos.d/docker-ce.repo
repo saved to /etc/yum.repos.d/docker-ce.repo

1.6 可以查看所有仓库中所有docker版本，并选择特定版本安装

$ yum list docker-ce --showduplicates | sort -r

docker-ce.x86_64            18.06.0.ce-3.el7                    docker-ce-stable
docker-ce.x86_64            18.03.1.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            18.03.0.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.12.1.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.12.0.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.09.1.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.09.0.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.06.2.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.06.1.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.06.0.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.03.2.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.03.1.ce-1.el7.centos             docker-ce-stable
docker-ce.x86_64            17.03.0.ce-1.el7.centos             docker-ce-stable

1.7 安装docker

$ sudo yum install docker-ce  #由于repo中默认只开启stable仓库，故这里安装的是最新稳定版17.12.0
$ sudo yum install   # 例如:sudo yum install docker-ce-17.12.1.ce

已安装:
  docker-ce.x86_64 0:17.12.1.ce-1.el7.centos                                                                                                            
作为依赖被安装:
  audit-libs-python.x86_64 0:2.8.1-3.el7           checkpolicy.x86_64 0:2.5-6.el7                 container-selinux.noarch 2:2.66-1.el7               
  libsemanage-python.x86_64 0:2.5-11.el7           libtool-ltdl.x86_64 0:2.4.2-22.el7_3           policycoreutils-python.x86_64 0:2.5-22.el7          
  python-IPy.noarch 0:0.75-6.el7                   setools-libs.x86_64 0:3.3.8-2.el7             

完毕！

1.8 将docker加入开机启动

$ sudo systemctl start docker
$ sudo systemctl enable docker

1.9 验证安装是否成功(有client和service两部分表示docker安装启动都成功了)

$ sudo docker version

Client:
 Version:    17.12.1-ce
 API version:    1.35
 Go version:    go1.9.4
 Git commit:    7390fc6
 Built:    Tue Feb 27 22:15:20 2018
 OS/Arch:    linux/amd64

Server:
 Engine:
  Version:    17.12.1-ce
  API version:    1.35 (minimum version 1.12)
  Go version:    go1.9.4
  Git commit:    7390fc6
  Built:    Tue Feb 27 22:17:54 2018
  OS/Arch:    linux/amd64
  Experimental:    false
  

默认情况下，docker 命令会使用 Unix socket 与 Docker 引擎通讯。而只有 root 用户和 docker 组的用户才可以访问 Docker 引擎的 Unix socket。出于安全考虑，一般 Linux 系统上不会直接使用 root 用户。因此，更好地做法是将需要使用 docker 的用户加入 docker 用户组。

2.1 建立docker组

$ sudo groupadd docker

2.2 将当前用户加入 docker 组：

$ sudo usermod -aG docker $USER

2.3 退出当前终端并重新登录，进行如下测试。

$ docker version #无需sudo使用管理员权限

 Client:
 Version:    17.12.1-ce
 API version:    1.35
 Go version:    go1.9.4
 Git commit:    7390fc6
 Built:    Tue Feb 27 22:15:20 2018
 OS/Arch:    linux/amd64

Server:
 Engine:
  Version:    17.12.1-ce
  API version:    1.35 (minimum version 1.12)
  Go version:    go1.9.4
  Git commit:    7390fc6
  Built:    Tue Feb 27 22:17:54 2018
  OS/Arch:    linux/amd64
  Experimental:    false

$ docker run hello-world #运行hello world

Unable to find image "hello-world:latest" locally
latest: Pulling from library/hello-world
9db2ca6ccae0: Pull complete 
Digest: sha256:4b8ff392a12ed9ea17784bd3c9a8b1fa3299cac44aca35a85c90c5e3c7afacdc
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/engine/userguide/

$ docker image ls #列出镜像

仓库名              标签                 镜像ID              创建时间            占用空间
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
hello-world         latest              2cb0d9787c4d        2 weeks ago         1.85kB