Linode StackScript for Debian with git, SSH, Docker

Debian-Docker-SSH-StackScript.sh

#!/bin/bash
# Brings up a Linode VPS with Debian kernel with git, SSH, Docker and firewall installed
# <UDF name="sys_hostname" label="System hostname" default="myvps" example="Name of your server, i.e. linode1." />
# <UDF name="user_name" label="User account name" example="This is the account that you will be using to log in." />
# <UDF name="user_password" label="User password" />
# <UDF name="user_sshkey" label="Public Key for user" default="" example="Recommended method of authentication. It is more secure than password log in." />

# fail immediately if cmd fails; unset env variables will fail the script:
set -e
set -u
exec &> /root/stackscript.log

# if [ -f /etc/debian_version ]; then
# fi

source <ssinclude StackScriptID=1>
export DEBIAN_FRONTEND=noninteractive

system_update

MY_IP = system_primary_ip

system_set_hostname $sys_hostname
system_add_host_entry $MY_IP $sys_hostname

function general_tools {
    aptitude -y install htop iotop iftop zip mc git-core
}

function add_user_with_sudo {
    USERNAME="$1"
    USERPASS="$2"
    if [ ! -n "$USERNAME" ] || [ ! -n "$USERPASS" ]; then
        echo "No new username and/or password entered"
        return 1;
    fi

    adduser "$USERNAME" --disabled-password --gecos ""
    echo "$USERNAME:$USERPASS" | chpasswd
    apt-get install -y sudo
    usermod -aG sudo "$USERNAME"
}

add_user_with_sudo $user_name $user_password
general_tools
goodstuff
restartServices