check if docker is installed code example

Example 1: Start the Docker daemon

sudo systemctl start docker
sudo service docker start

Example 2: check if docker is running

systemctl status docker

Example 3: how to check if i have docker installed

$ docker -v
Docker version 1.7.0, build 0baf609
$ echo $?
0

Example 4: check if docker is installed ubuntu

$ docker -v