AWS EC2 Ubuntu instance configuration script

aws-ec2-init-ubuntu.sh

#!/bin/bash
#
# Script executed automatically upon launch of an AWS EC2 Ubuntu instance.
#
# Pass this script as the "user data" to the instance launching process:
#
# - Web Console: Step 3
# - CLI: aws ec2 run-instances ... --user-data "commands..."
#
# Note that all commands in this script are executed as root in /root.
#
# Output of this script is in /var/log/cloud-init-output.log
#
# Reference: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/user-data.html
#------------------------------------------------------------------------------#

# Install dotfiles 
runuser -l ubuntu -c 'curl -Lks http://bit.ly/get-my-dotfiles | bash'

# Install Docker and add user 'ubuntu' to group 'docker'
apt-get update
apt-get install -y docker.io
sudo usermod -aG docker ubuntu

# Listen on an additional port (default is 22) for SSH connections
echo "Port 4500" >>/etc/ssh/sshd_config
service sshd restart

# Add function for printing public DNS hostname of this instance
runuser -l ubuntu -c "echo 'public-hostname() { curl -s http://169.254.169.254/latest/meta-data/public-hostname && echo; }' >>~/.bashrc_trash"