ubuntu环境下docker安装步骤

本文是根据docker官方文档翻译，原文：https://docs.docker.com/engine/installation/linux/ubuntulinux/

Docker 支持以下 Ubuntu 系统:Ubuntu Xenial 16.04 (LTS)
Ubuntu Wily 15.10
Ubuntu Trusty 14.04 (LTS)
Ubuntu Precise 12.04 (LTS)
本页内容指引你安装使用由Docker管理的正式包和管理包. 使用这些安装包能确保你安装 Docker最新发行包. 如果你想安装并使用Ubuntu管理提供的软件包, 参照Ubuntu文档.备注: Ubuntu Utopic 14.10 和 15.04 依旧在 Docker’s 

APT

 仓库中，但不再提供官方技术支持.

前提条件

Docker要求是64位Ubuntu（无论哪个版本）。另外，内核必须在最小为3.10。3.10最新版本或更新的版本也行。3.10之前版本缺少docker运行所需要的特征一些容器。这些老版本的bug，经常导致数据损失。使用命令： 

uname -r

 来显示内核版本:

$ uname -r
3.11.0-15-generic

备注: 如果你之前安装过Docker 使用的

APT

, 确保升级你的

APT

源 到 Docker新版.

更新

APT

源

Docker’s 

APT

 仓库 包括 Docker 1.7.1 及更高版本. 为了设定 

APT

 使用最新仓库的软件包，:使用 

sudo

 or 

root

 权限登陆计算机.
打开 terminal window（命令窗口）.
更新安装包信息, 确保 APT 使用 

https

 协议, 同时CA 证书已经被安装.

$ sudo apt-get update
$ sudo apt-get install apt-transport-https ca-certificates

添加新的

GPG

key.

$ sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D

用编辑器打开  

/etc/apt/sources.list.d/docker.list

.如果不存在，则新建一个
删除任何现有输入.
添加与您Ubuntu操作系统相关条目。该条目可以是：On Ubuntu Precise 12.04 (LTS)

deb https://apt.dockerpr 4000
oject.org/repo ubuntu-precise main

On Ubuntu Trusty 14.04 (LTS)

deb https://apt.dockerproject.org/repo ubuntu-trusty main

Ubuntu Wily 15.10

deb https://apt.dockerproject.org/repo ubuntu-wily main

Ubuntu Xenial 16.04 (LTS)

deb https://apt.dockerproject.org/repo ubuntu-xenial main

备注: Docker没有为所有架构提供代码包 .你可以找到 nightly built binaries in https://master.dockerproject.org. To install docker on a multi-architecture system, add an 

[arch=...]

 clause to the entry. 详细内容参考 Debian Multiarch wiki .
保存并关闭  

/etc/apt/sources.list.d/docker.list

 file.
更新

APT

 软件包索引.

$ sudo apt-get update

清除旧的repo if it exists.

$ sudo apt-get purge lxc-docker

确保 

APT

 是从正确的代码库拉取下来的.

$ apt-cache policy docker-engine

至此，你可以 使用命令

apt-get upgrade

, 

APT

 从新代码库拉取代码.

 Ubuntu 版本相关的先决条件

Ubuntu Xenial 16.04 (LTS)
Ubuntu Wily 15.10
Ubuntu Trusty 14.04 (LTS)
针对Ubuntu Trusty, Wily, and Xenial, 推荐安装 the 

linux-image-extra-*

 内核包.  

linux-image-extra-*

 包允许你使用 

aufs

存储驱动.为了安装 

linux-image-extra-*

 :打开主机命令窗口.
更新包管理器.

$ sudo apt-get update

安装推荐包.

$ sudo apt-get install linux-image-extra-$(uname -r) linux-image-extra-virtual

继续安装 Docker.

Ubuntu Precise 12.04 (LTS)

针对Ubuntu Precise, Docker 要求是 3.13内核. 如果内核版本早于 3.13, 必须更新. 参考如下表格来对比不同包对运行环境的要求:

Package	Description
linux-image-generic-lts-trusty	Generic Linux kernel image. This kernel has AUFS built in. This is required to run Docker.
linux-headers-generic-lts-trusty	Allows packages such as ZFS and VirtualBox guest additions which depend on them. If you didn't install the headers for your existing kernel, then you can skip these headers for the"trusty" kernel. If you're unsure, you should include this package for safety.
xserver-xorg-lts-trusty	Optional in non-graphical environments without Unity/Xorg. Required when running Docker on machine with a graphical environment. To learn more about the reasons for these packages, read the installation instructions for backported kernels, specifically the LTS Enablement Stack — refer to note 5 under each version.
libgl1-mesa-glx-lts-trusty

为了更新linux内核并且安装附加包, 通过以下步骤:打开主机命令窗口.
更新包管理器.

$ sudo apt-get update

安装必需包和可选包

$ sudo apt-get install linux-image-generic-lts-trusty

根据你的运行环境, 你可能需要根据之前提供表格所描述内容安装其他内容.
重启主机.

$ sudo reboot

重启之后, 继续安装Docker.

安装

确保你已经安装过你的Ubuntu版本所需前提要求.然后, 通过以下步骤安装Docker:用具有

sudo权限的用户登陆

Ubuntu.
Update your 

APT

 package index.

$ sudo apt-get update

安装 Docker.

$ sudo apt-get install docker-engine

开始使用

docker

.

$ sudo service docker start

确认

docker

已被正确安装.

$ sudo docker run hello-world

这个命令下载一个测试图片并且在容器（container）中运行. 然后容器container运行, 打印出相关信息.说明安装成功.

可选配置

下面驱动包含一些可选步骤用来配置Ubuntu环境下Docker.Create a docker group
Adjust memory and swap accounting
Enable UFW forwarding
Configure a DNS server for use by Docker
Configure Docker to start on boot

创建 Docker group

docker

 进程（daemon）绑定在 Unix套接字（socket）， 而不是TCP端口（port）. 由于Unix默认是 socket权限归

root用户所有，其他用户可以通过

sudo访问

. 由此, 

docker

进程通常使用

root

用户运行.

为了避免每次使用docker命令都不得不使用sudo

, 创建名为

docker的

Unix group并add users to it. 当

docker

 daemon 开始,

docker

 group就会拥有Unix socket 的读写权限（read/writable）.警告: The 

docker

 group is equivalent to the 

root

用户; For details on how this impacts security in your system, 查看Docker Daemon Attack Surface 查看细节.为了

docker

 group and添加用户user:使用具有

sudo

权限得用户登录Ubuntu.
创建

docker

 group.

$ sudo groupadd docker

添加user到

docker

 group.

$ sudo usermod -aG docker $USER

Log out and log back in.This ensures your user is running with the correct permissions.

确认不使用

sudo可以运行docker

.

$ docker run hello-world

如果提示失败信息与下面相似:

Cannot connect to the Docker daemon. Is 'docker daemon' running on this host?

检查 

DOCKER_HOST

 环境变量 没有设置shell. 如果这样,重置他.

Adjust memory and swap accounting

When users run Docker, they may see these messages when working with an image:

WARNING: Your kernel does not support cgroup swap limit. WARNING: Your
kernel does not support swap limit capabilities. Limitation discarded.

To prevent these messages, enable memory and swap accounting on your system. Enabling memory and swap accounting does induce both a memory overhead and a performance degradation even when Docker is not in use. The memory overhead is about 1% of the total available memory. The performance degradation is roughly 10%.To enable memory and swap on system using GNU GRUB (GNU GRand Unified Bootloader), do the following:Log into Ubuntu as a user with 

sudo

 privileges.
Edit the 

/etc/default/grub

 file.
Set the 

GRUB_CMDLINE_LINUX

 value as follows:

GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"

Save and close the file.
Update GRUB.

$ sudo update-grub

Reboot your system.

Enable UFW forwarding

If you use UFW (Uncomplicated Firewall) on the same host as you run Docker, you’ll need to do additional configuration. Docker uses a bridge to manage container networking. By default, UFW drops all forwarding traffic. As a result, for Docker to run when UFW is enabled, you must set UFW’s forwarding policy appropriately.Also, UFW’s default set of rules denies all incoming traffic. If you want to reach your containers from another host allow incoming connections on the Docker port. The Docker port defaults to 

2376

 if TLS is enabled or 

2375

 when it is not. If TLS is not enabled, communication is unencrypted. By default, Docker runs without TLS enabled.To configure UFW and allow incoming connections on the Docker port:Log into Ubuntu as a user with 

sudo

 privileges.
Verify that UFW is installed and enabled.

$ sudo ufw status

Open the 

/etc/default/ufw

 file for editing.

$ sudo nano /etc/default/ufw

Set the 

DEFAULT_FORWARD_POLICY

 policy to:

DEFAULT_FORWARD_POLICY="ACCEPT"

Save and close the file.
Reload UFW to use the new setting.

$ sudo ufw reload

Allow incoming connections on the Docker port.

$ sudo ufw allow 2375/tcp

Configure a DNS server for use by Docker

Systems that run Ubuntu or an Ubuntu derivative on the desktop typically use

127.0.0.1

 as the default 

nameserver

 in 

/etc/resolv.conf

 file. The NetworkManager also sets up 

dnsmasq

 to use the real DNS servers of the connection and sets up 

nameserver 127.0.0.1

 in /

etc/resolv.conf

.When starting containers on desktop machines with these configurations, Docker users see this warning:

WARNING: Local (127.0.0.1) DNS resolver found in resolv.conf and containers
can't use it. Using default external servers : [8.8.8.8 8.8.4.4]

The warning occurs because Docker containers can’t use the local DNS nameserver. Instead, Docker defaults to using an external nameserver.To avoid this warning, you can specify a DNS server for use by Docker containers. Or, you can disable 

dnsmasq

 in NetworkManager. Though, disabling

dnsmasq

 might make DNS resolution slower on some networks.The instructions below describe how to configure the Docker daemon running on Ubuntu 14.10 or below. Ubuntu 15.04 and above use 

systemd

 as the boot and service manager. Refer to control and configure Docker with systemd to configure a daemon controlled by 

systemd

.To specify a DNS server for use by Docker:Log into Ubuntu as a user with 

sudo

 privileges.
Open the 

/etc/default/docker

 file for editing.

$ sudo nano /etc/default/docker

Add a setting for Docker.

DOCKER_OPTS="--dns 8.8.8.8"

Replace 

8.8.8.8

 with a local DNS server such as 

192.168.1.1

. You can also specify multiple DNS servers. Separated them with spaces, for example:

--dns 8.8.8.8 --dns 192.168.1.1

Warning: If you’re doing this on a laptop which connects to various networks, make sure to choose a public DNS server.
Save and close the file.
Restart the Docker daemon.

$ sudo service docker restart

   Or, as an alternative to the previous procedure, disable 

dnsmasq

 in NetworkManager (this might slow your network).Open the 

/etc/NetworkManager/NetworkManager.conf

 file for editing.

$ sudo nano /etc/NetworkManager/NetworkManager.conf

Comment out the 

dns=dnsmasq

 line:

dns=dnsmasq

保存并关闭.
重启NetworkManager 和 Docker.

$ sudo restart network-manager
$ sudo restart docker

Configure Docker to start on boot

Ubuntu uses 

systemd

 as its boot and service manager 

15.04

 onwards and

upstart

 for versions 

14.10

 and below.For 

15.04

 and up, to configure the 

docker

 daemon to start on boot, run

$ sudo systemctl enable docker

For 

14.10

 and below the above installation method automatically configures

upstart

 to start the docker daemon on boot

更新Docker

使用apt-get来安装Docker最新版:

$ sudo apt-get upgrade docker-engine

卸载

卸载Docker包:

$ sudo apt-get purge docker-engine

卸载Docker包及依赖:

$ sudo apt-get autoremove --purge docker-engine

上面命令会删除images, containers, volumes, user created configuration files on your host. If you wish to delete all images, containers, and volumes run the following command:

$ rm -rf /var/lib/docker

You must delete the user created configuration files manually.请把你的疑问评论在下方。