install-docker.sh

#!/usr/bin/env bash

##
# This script installs docker and docker-compose on an ubuntu host
# Additionally it:
# - Adds a user to the docker group (to simplify permissions in development)
# - Configures docker to run with bridged networking by default
##

set -e
if (( EUID != 0 )); then
    echo "You must be root to do this." 1>&2
    exit 1
fi

if [ -z "$1" ]; then
    echo "Must specify user to add to docker group"
    echo "example: $0 some_user"
    exit 1
fi

DOCKER_USER=$1

echo "Updating apt sources and upgrading packages"
apt-get update -qqy
apt-get upgrade -qqy
apt-get install -qqy \
    apt-transport-https \
    bridge-utils \
    ca-certificates \
    dnsmasq \
    git \
    linux-image-extra-$(uname -r)

echo "Adding docker repository to apt"
apt-key adv \
    --keyserver hkp://p80.pool.sks-keyservers.net:80 \
    --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
echo "deb https://apt.dockerproject.org/repo ubuntu-`lsb_release -cs` main" | tee -a /etc/apt/sources.list.d/docker.list

echo "Installing docker"
apt-get update -qqy
apt-get purge -qqy lxc-docker
apt-get install -qqy docker-engine

echo "Adding user: $DOCKER_USER to docker group"
usermod -aG docker $DOCKER_USER


echo "Installing docker-compose"
curl -L https://github.com/docker/compose/releases/download/1.8.0/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose
chmod ugo+x /usr/local/bin/docker-compose

echo "Configuring network bridge for docker"
if [ $(pidof /sbin/init) ]; then
    echo "Sysvinit detected, writing config to /etc/default/docker"
    cat <<EOF > /etc/default/docker
DOCKER_OPTS="--bridge=docker0"
EOF

elif [ $(pidof systemd) ]; then

    ## ubuntu with systemd
    systemctl enable docker
    
    echo "systemd detected, writing config to /etc/systemd/system/docker.service.d/docker.conf"
    #https://docs.docker.com/engine/installation/linux/ubuntulinux/#/adjust-memory-and-swap-accounting
    mkdir /etc/systemd/system/docker.service.d
    cat <<EOF > /etc/systemd/system/docker.service.d/docker.conf
[Service]                                                 
ExecStart=                                                
ExecStart=/usr/bin/docker daemon --bridge=docker0 -H fd://
EOF

systemctl daemon-reload
systemctl restart docker

else
	echo "No init system detected, exiting."
	exit 1
fi

echo "
Installation complete!

User $DOCKER_USER has been added to the docker group. This user will need
to start a new login shell to access docker.

verify installation:
docker images"