docker command not found even though installed with apt-get - docker

Question

Adding this for reference for others because it would have saved me 10 minutes if such an answer existed.
I tried installing Docker using ubuntu 14.0LTS virtualbox
sudo apt get install docker
However, when I try running docker it gives me the following error
The program 'docker' is currently not installed. You can install it by typing:
sudo apt-get install docker
Why is ubuntu not seeing docker?

Answer 1

The Ubuntu package docker actually refers to a GUI application, not the beloved DevOps tool we've come out to look for.
The instructions for docker can be followed per instructions on the docker page here: https://docs.docker.com/engine/install/ubuntu/
=== UPDATED (thanks #Scott Stensland) ===
You now run the following install script to get docker:
curl -sSL https://get.docker.com/ | sudo sh
Note: review the script on the website and make sure you have the right link before continuing since you are running this as sudo.
This will run a script that installs docker. Note the last part of the script:
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!
To update Docker run:
sudo apt-get update && sudo apt-get upgrade
For more details on what's going on,
See the docker install documentation or #Scott Stensland's answer below
.
=== UPDATE: For those uncomfortable w/ sudo | sh ===
Some in the comments have mentioned that it a risk to run an arbitrary script as sudo. The above option is a convenience script from docker to make the task simple. However, for those that are security-focused but don't want to read the script you can do the following:
Add Dependencies
sudo apt-get update; \
sudo apt-get install \
apt-transport-https \
ca-certificates \
curl \
gnupg-agent \
software-properties-common
Add docker gpg key
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
(Security check, verify key fingerprint 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]
)
Setup Repository
sudo add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"
Install Docker
sudo apt-get update; \
sudo apt-get install docker-ce docker-ce-cli containerd.io
If you want to verify that it worked run:
sudo docker run hello-world
The following explains why it is named like this:
Why install docker on ubuntu should be `sudo apt-get install docker.io`?

Answer 2

IMPORTANT - ubuntu package docker is something entirely different ( avoid it ) :
issue following to view what if any packages you have mentioning docker
dpkg -l|grep docker
if only match is following then you do NOT have docker installed below is an unrelated package
docker - System tray for KDE3/GNOME2 docklet applications
if you do see above lets remove it since its the wrong docker
sudo apt-get remove docker # remove the wrong docker
if you see something similar to following then you have docker installed
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
NOTE - ubuntu package docker.io is not getting updates ( obsolete do NOT use )
Instead do this : install the latest version of docker on linux by executing the following:
sudo apt-get install docker-ce
below is yet another way to issue the install command
sudo curl -sSL https://get.docker.com/ | sh
# sudo curl -sSL https://test.docker.com | sh # get dev pipeline version
here is a typical output ( 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!
Here is the underlying detailed install instructions which as you can see comes bundled into above technique ... Above one liner gives you same as :
https://docs.docker.com/engine/installation/linux/ubuntulinux/
Once installed you can see what docker packages were installed by issuing
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
now Docker updates will get installed going forward when you issue
sudo apt-get update
sudo apt-get upgrade
take a look at
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
or more generally
cd /etc/apt
grep -r docker *
sources.list.d/docker.list:deb [arch=amd64] https://download.docker.com/linux/ubuntu focal test

Answer 3

sudo apt-get install docker # DO NOT do this
is a different library on ubuntu.
Use sudo apt-get install docker-ce to install the correct docker.

Answer 4

If you want to install docker in an easy way.
Just type:
$sudo apt install docker.io
And, it will start installing.
And, to check whether its working or not type:
$docker

Answer 5

SET UP THE REPOSITORY
For 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"
For Ubuntu 17.10:
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu zesty stable"
Add Docker’s official GPG key:
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
Then install
$ sudo apt-get update && sudo apt-get -y install docker-ce