docker镜像文件下载_docker安装centos7镜像

1 安装docker的apt源

apt-get install apt-transport-https ca-certificates curl software-properties-common

2 添加docker官方的GPG

root@zhf-linux:/home# curl -s https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add –

3 添加docker的源。如果没有docker.list则自己创建一个

root@zhf-linux:/etc/apt/sources.list.d# bash -c “echo deb https://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list”

4 安装docker

apt install docker.io

5 查看docker的版本：

root@zhf-linux:/var/lib/docker# docker version

Client:

Version: 1.13.1

API version: 1.26

Go version: go1.6.2

Git commit: 092cba3

Built: Thu Sep 7 17:23:05 2017

OS/Arch: linux/386

Server:

Version: 1.13.1

API version: 1.26 (minimum version 1.12)

Go version: go1.6.2

Git commit: 092cba3

Built: Thu Sep 7 17:23:05 2017

OS/Arch: linux/386

Experimental: false

到这里docker整个就安装完了，我们来看下如何来启动一个镜像

1 通过docker run命令来启动一个httpd的镜像。如果没有发现httpd镜像会从docker hub下载镜像。下载完成后，镜像httpd被保存到本地

docker run -d -p 80:80 httpd

2 docker images可以看到已经下载到本地

root@zhf-linux:/home/zhf/zhf/c_prj/make_function# docker images

REPOSITORY TAG IMAGE ID CREATED SIZE

httpd latest 7659d5a9a057 2 weeks ago 189 MB

3 docker ps显示容器正在运行

root@zhf-linux:/home/zhf/zhf/c_prj/make_function# docker ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

39ae70ca12b2 httpd “httpd-foreground” 6 minutes ago Up 6 minutes 0.0.0.0:80->80/tcp compassionate_bohr

接下来看下如何下载一个镜像。通过docker pull下载。docker pull会从Docker Hub进行下载。

root@zhf-linux:/home/zhf/zhf/c_prj/make_function# docker pull hello-world

Using default tag: latest

latest: Pulling from library/hello-world

cf7dde121f94: Pull complete

Digest: sha256:0e06ef5e1945a718b02a8c319e15bae44f47039005530bc617a5d071190ed3fc

Status: Downloaded newer image for hello-world:latest

通过docker images看到这个镜像只有600多K

root@zhf-linux:/home/zhf/zhf/c_prj/make_function# docker images hello-world

REPOSITORY TAG IMAGE ID CREATED SIZE

hello-world latest abd130ec0722 3 months ago 665 kB

通过docker run hello-world来执行。结果如下：

root@zhf-linux:/home/zhf/zhf/c_prj/make_function# docker run hello-world

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.

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://cloud.docker.com/

For more examples and ideas, visit:

https://docs.docker.com/engine/userguide/

下载的docker镜像默认存储路径是/var/lib/docker .具体的镜像文件就在containers文件夹中

root@zhf-linux:/var/lib/docker# ls -al

total 44

drwx–x–x 11 root root 4096 Oct 30 22:28 .

drwxr-xr-x 79 root root 4096 Dec 11 21:08 ..

drwx—— 5 root root 4096 Oct 30 22:28 aufs

drwx—— 8 root root 4096 Dec 19 20:59 containers

drwx—— 3 root root 4096 Oct 30 22:28 image

drwxr-x— 3 root root 4096 Oct 30 22:28 network

drwx—— 4 root root 4096 Oct 30 22:28 plugins

drwx—— 2 root root 4096 Oct 30 22:28 swarm

drwx—— 2 root root 4096 Dec 19 20:50 tmp

drwx—— 2 root root 4096 Oct 30 22:28 trust

drwx—— 2 root root 4096 Oct 30 22:28 volumes

Dockerfile是镜像的描述文件，定义了如何构建Docker镜像。Dockerfile需要到docker网站去查看：

https://hub.docker.com/

查看方法如下：

1 首先在网站上注册一个docker账号

2 在上面的搜索栏中输入hello-world