添加此内容以供其他人参考，因为如果存在这样的答案，它将为我节省 10 分钟。
我尝试使用 ubuntu 14.0LTS virtualbox 安装 Docker
sudo apt get install docker
但是，当我尝试运行 docker 时，它给了我以下错误
The program 'docker' is currently not installed. You can install it by typing:
sudo apt-get install docker
为什么 ubuntu 看不到 docker？
【问题讨论】：
标签： docker ubuntu-14.04
Ubuntu 软件包 docker 实际上是指一个 GUI 应用程序，而不是我们寻找的心爱的 DevOps 工具。
可以按照此处 docker 页面上的说明遵循 docker 的说明：https://docs.docker.com/engine/install/ubuntu/
=== 已更新（感谢@Scott Stensland）===
您现在运行以下安装脚本来获取 docker：
sudo curl -sSL https://get.docker.com/ | sh
这将运行一个安装 docker 的脚本。注意脚本的最后一部分：
If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:
sudo usermod -aG docker stens
Remember that you will have to log out and back in for this to take effect!
更新 Docker 运行：
sudo apt-get update && sudo apt-get upgrade
如需了解更多详情， 请参阅下面的docker install documentation 或@Scott Stensland 的回答
.
=== 更新：对于那些使用 sudo 感到不舒服的人 | sh ===
cmets 中的一些人提到将任意脚本作为 sudo 运行是有风险的。上面的选项是一个来自 docker 的便捷脚本，用于简化任务。但是，对于那些注重安全但不想阅读脚本的人，您可以执行以下操作：
sudo apt-get update; \
sudo apt-get install \
apt-transport-https \
ca-certificates \
curl \
gnupg-agent \
software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
(安全检查，验证密钥指纹9DC8 5822 9FC7 DD38 854A E2D8 8D81 803C 0EBF CD88
$ sudo apt-key fingerprint 0EBFCD88
pub rsa4096 2017-02-22 [SCEA]
9DC8 5822 9FC7 DD38 854A E2D8 8D81 803C 0EBF CD88
uid [ unknown] Docker Release (CE deb) <docker@docker.com>
sub rsa4096 2017-02-22 [S]
)
sudo add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"
sudo apt-get update; \
sudo apt-get install docker-ce docker-ce-cli containerd.io
如果您想验证它是否有效，请运行：
sudo docker run hello-world
下面解释了它为什么这样命名： Why install docker on ubuntu should be `sudo apt-get install docker.io`?
【讨论】：
apt-cache search docker 会告诉你很多东西，其中docklet KDE 3/GNOME 2 不是你要找的，Linux container runtime 更好
sudo curl | sh 看起来是个坏主意吗？
重要 - ubuntu 软件包 docker 完全不同（避免使用它）：
发出以下问题以查看是否有任何软件包提到了 docker
dpkg -l|grep docker
如果只有匹配，那么你下面没有安装 docker 是一个不相关的包
docker - KDE3/GNOME2 docker 应用程序的系统托盘
如果您确实看到上面的内容，请删除它，因为它是错误的 docker
sudo apt-get remove docker #删除错误的docker
如果你看到类似下面的内容，那么你已经安装了 docker
dpkg -l|grep docker
ii docker-ce 5:19.03.13~3-0~ubuntu-focal amd64 Docker: the open-source application container engine
ii docker-ce-cli 5:19.03.13~3-0~ubuntu-focal amd64 Docker CLI: the open-source application container engine
注意 - ubuntu 包 docker.io 未获得更新（已过时请勿使用）
改为这样做：通过执行以下命令在 linux 上安装最新版本的 docker：
sudo apt-get install docker-ce
下面是另一种发出安装命令的方法
sudo curl -sSL https://get.docker.com/ | sh
# sudo curl -sSL https://test.docker.com | sh # get dev pipeline version
这是一个典型的输出（ubuntu 16.04）
apparmor is enabled in the kernel and apparmor utils were already installed
+ sudo -E sh -c apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
Executing: /tmp/tmp.rAAGu0P85R/gpg.1.sh --keyserver
hkp://ha.pool.sks-keyservers.net:80
--recv-keys
58118E89F3A912897C070ADBF76221572C52609D
gpg: requesting key 2C52609D from hkp server ha.pool.sks-keyservers.net
gpg: key 2C52609D: "Docker Release Tool (releasedocker) <docker@docker.com>" 1 new signature
gpg: Total number processed: 1
gpg: new signatures: 1
+ break
+ sudo -E sh -c apt-key adv -k 58118E89F3A912897C070ADBF76221572C52609D >/dev/null
+ sudo -E sh -c mkdir -p /etc/apt/sources.list.d
+ dpkg --print-architecture
+ sudo -E sh -c echo deb [arch=amd64] https://apt.dockerproject.org/repo ubuntu-xenial main > /etc/apt/sources.list.d/docker.list
+ sudo -E sh -c sleep 3; apt-get update; apt-get install -y -q docker-engine
Hit:1 http://repo.steampowered.com/steam precise InRelease
Hit:2 http://download.virtualbox.org/virtualbox/debian xenial InRelease
Ign:3 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:4 http://dl.google.com/linux/chrome/deb stable Release
Hit:5 http://archive.canonical.com/ubuntu xenial InRelease
Hit:6 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial InRelease
Hit:7 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-updates InRelease
Hit:8 http://ppa.launchpad.net/me-davidsansome/clementine/ubuntu xenial InRelease
Ign:9 http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.2 InRelease
Hit:10 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-backports InRelease
Hit:11 http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.2 Release
Hit:12 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-security InRelease
Hit:14 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease
Ign:15 http://linux.dropbox.com/ubuntu wily InRelease
Ign:16 http://repo.vivaldi.com/stable/deb stable InRelease
Hit:17 http://repo.vivaldi.com/stable/deb stable Release
Get:18 http://linux.dropbox.com/ubuntu wily Release [6,596 B]
Get:19 https://apt.dockerproject.org/repo ubuntu-xenial InRelease [20.6 kB]
Ign:20 http://packages.amplify.nginx.com/ubuntu xenial InRelease
Hit:22 http://packages.amplify.nginx.com/ubuntu xenial Release
Hit:23 https://deb.opera.com/opera-beta stable InRelease
Hit:26 https://deb.opera.com/opera-developer stable InRelease
Get:28 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 Packages [1,719 B]
Hit:29 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease
Fetched 28.9 kB in 1s (17.2 kB/s)
Reading package lists... Done
W: http://repo.mongodb.org/apt/debian/dists/wheezy/mongodb-org/3.2/Release.gpg: Signature by key 42F3E95A2C4F08279C4960ADD68FA50FEA312927 uses weak digest algorithm (SHA1)
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
aufs-tools cgroupfs-mount
The following NEW packages will be installed:
aufs-tools cgroupfs-mount docker-engine
0 upgraded, 3 newly installed, 0 to remove and 17 not upgraded.
Need to get 14.6 MB of archives.
After this operation, 73.7 MB of additional disk space will be used.
Get:1 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial/universe amd64 aufs-tools amd64 1:3.2+20130722-1.1ubuntu1 [92.9 kB]
Get:2 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial/universe amd64 cgroupfs-mount all 1.2 [4,970 B]
Get:3 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 docker-engine amd64 1.11.2-0~xenial [14.5 MB]
Fetched 14.6 MB in 7s (2,047 kB/s)
Selecting previously unselected package aufs-tools.
(Reading database ... 427978 files and directories currently installed.)
Preparing to unpack .../aufs-tools_1%3a3.2+20130722-1.1ubuntu1_amd64.deb ...
Unpacking aufs-tools (1:3.2+20130722-1.1ubuntu1) ...
Selecting previously unselected package cgroupfs-mount.
Preparing to unpack .../cgroupfs-mount_1.2_all.deb ...
Unpacking cgroupfs-mount (1.2) ...
Selecting previously unselected package docker-engine.
Preparing to unpack .../docker-engine_1.11.2-0~xenial_amd64.deb ...
Unpacking docker-engine (1.11.2-0~xenial) ...
Processing triggers for libc-bin (2.23-0ubuntu3) ...
Processing triggers for man-db (2.7.5-1) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for systemd (229-4ubuntu6) ...
Setting up aufs-tools (1:3.2+20130722-1.1ubuntu1) ...
Setting up cgroupfs-mount (1.2) ...
Setting up docker-engine (1.11.2-0~xenial) ...
Processing triggers for libc-bin (2.23-0ubuntu3) ...
Processing triggers for systemd (229-4ubuntu6) ...
Processing triggers for ureadahead (0.100.0-19) ...
+ sudo -E sh -c docker version
Client:
Version: 1.11.2
API version: 1.23
Go version: go1.5.4
Git commit: b9f10c9
Built: Wed Jun 1 22:00:43 2016
OS/Arch: linux/amd64
Server:
Version: 1.11.2
API version: 1.23
Go version: go1.5.4
Git commit: b9f10c9
Built: Wed Jun 1 22:00:43 2016
OS/Arch: linux/amd64
If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:
sudo usermod -aG docker stens
Remember that you will have to log out and back in for this to take effect!
这是底层的详细安装说明，如您所见，它与上述技术捆绑在一起......上面的一个衬里给您的效果与：
https://docs.docker.com/engine/installation/linux/ubuntulinux/
安装后，您可以通过发布查看安装了哪些 docker 包
dpkg -l|grep docker
ii docker-ce 5:19.03.13~3-0~ubuntu-focal amd64 Docker: the open-source application container engine
ii docker-ce-cli 5:19.03.13~3-0~ubuntu-focal amd64 Docker CLI: the open-source application container engine
现在 Docker 更新将在您发布时安装
sudo apt-get update
sudo apt-get upgrade
看看
ls -latr /etc/apt/sources.list.d/*docker*
-rw-r--r-- 1 root root 202 Jun 23 10:01 /etc/apt/sources.list.d/docker.list.save
-rw-r--r-- 1 root root 71 Jul 4 11:32 /etc/apt/sources.list.d/docker.list
cat /etc/apt/sources.list.d/docker.list
deb [arch=amd64] https://apt.dockerproject.org/repo ubuntu-xenial main
或更一般地
cd /etc/apt
grep -r docker *
sources.list.d/docker.list:deb [arch=amd64] https://download.docker.com/linux/ubuntu focal test
【讨论】：
sudo apt-get install docker # DO NOT do this
是 ubuntu 上的不同库。
使用sudo apt-get install docker-ce 安装正确的docker。
【讨论】：
System tray for KDE3/GNOME2 docklet applications
设置存储库
对于 Ubuntu 14.04/16.04/16.10/17.04：
sudo add-apt-repository "deb [arch=amd64] \
https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
对于 Ubuntu 17.10：
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu zesty stable"
添加 Docker 的官方 GPG 密钥：
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
然后安装
$ sudo apt-get update && sudo apt-get -y install docker-ce
【讨论】：