I am typing


$ sudo apt install docker

Reading package lists... Done

Building dependency tree

Reading state information... Done

The following package was automatically installed and is no longer required:


Use 'sudo apt autoremove' to remove it.

The following NEW packages will be installed:


0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.

Need to get 12.2 kB of archives.

After this operation, 65.5 kB of additional disk space will be used.

Get:1 http://us-central1.gce.archive.ubuntu.com/ubuntu xenial/universe amd64 docker amd64 1.5-1 [12.2 kB]

Fetched 12.2 kB in 0s (132 kB/s)

Selecting previously unselected package docker.

(Reading database ... 158032 files and directories currently installed.)

Preparing to unpack .../docker_1.5-1_amd64.deb ...

Unpacking docker (1.5-1) ...

Processing triggers for man-db (2.7.5-1) ...

Setting up docker (1.5-1) ...

synhedionn@instance-7:~/POUB/docker-tomcat-tutorial$ docker

The program 'docker' is currently not installed. To run 'docker' please ask your administrator to install

the package 'docker.io'

synhedionn@instance-7:~/POUB/docker-tomcat-tutorial$ sudo docker

sudo: docker: command not found

So it says installed, but docker keyword is not available.

What happens ?