docker command not found even though installed with apt-get

Question

Adding this for reference for others because it would have saved me 10 minutes if such an answer existed.

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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:

`sudo curl -sSL https://get.docker.com/ | 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:

1. Add Dependencies

sudo apt-get update; \
sudo apt-get install \
 apt-transport-https \
 ca-certificates \
 curl \
 gnupg-agent \
 software-properties-common

2. 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) <[email protected]>
sub   rsa4096 2017-02-22 [S]

)

3. Setup Repository

sudo add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) \
   stable"

4. 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

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The following explains why it is named like this: Why install docker on ubuntu should be `sudo apt-get install docker.io`?