install-docker

#!/bin/bash

## local variables
DOCKER_VERSION="$1"

## install docker
if [ ! -x "$(command -v docker)" ];
then
    if uname -a | grep Ubuntu;
    then
        sudo apt-get -y install apt-transport-https \
            ca-certificates \
            curl \
            software-properties-common
        curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
        sudo add-apt-repository \
            "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
        sudo apt-get -y update
        sudo apt-get -y install docker-ce="$DOCKER_VERSION"
    else
        sudo yum install -y yum-utils \
            device-mapper-persistent-data \
            lvm2
        sudo yum-config-manager \
            --add-repo \
            https://download.docker.com/linux/centos/docker-ce.repo
        sudo yum install -y "docker-ce-${DOCKER_VERSION}"
    fi
fi

## ensure docker started
sudo service docker start
sudo systemctl start docker