Shell script to start/stop an EC2 instance to use as a ssh tunnel

tunnel.sh

#!/bin/bash

# Start/stop an EC2 instance to use as a ssh tunnel
# requires: 1. the aws package locally -- sudo apt-get install awscli
#           2. run `aws configure` to config aws environment beforehand
#
# usage: ./tunnel.sh start (spin up EC2 and create the tunnel)
#        ./tunnel.sh stop  (stop the EC2 instance to save money)
#        ./tunnel.sh status (show EC2 instance detail)
#        ./tunnel.sh resume (in case your tunnel is interrupted but the EC2 instance is still running)
#        ./tunnel.sh terminate (terminate the EC2 instance to save money)

# CHANGE THE PARAMETERS BELOW

imageid="ami-ab77d4c5" # this is an Ubuntu AMI (Ubuntu Server 16.04 LTS (HVM), SSD Volume Type), but you can change it to whatever you want
instance_type="t2.nano"
key_name="myawskeypairname" # your keypair name -- http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html
security_group="my-security-group" # your security group -- http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-network-security.html
wait_seconds="30" # seconds between polls for the public IP to populate (keeps it from hammering their API)
port="5222" # the SSH tunnel port you want
key_location="/home/aws/keypair.pem" # your private key -- http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html#having-ec2-create-your-key-pair
user="ubuntu" # the EC2 linux user name

# END SETTINGS

# --------------------- you shouldn't have to change much below this ---------------------

# private
connect ()
{
	ssh -oStrictHostKeyChecking=no -ND $port -i $key_location $user@$ip
}

# private
getip ()
{
	ip=$(aws ec2 describe-instances --filters "Name=image-id,Values=${imageid}" "Name=instance-state-code,Values=16" | grep PublicIpAddress | grep -E -o "([0-9]{1,3}[\.]){3}[0-9]{1,3}")
}

# private
getinstance ()
{
	instance=$(aws ec2 describe-instances --filters "Name=image-id,Values=${imageid}" "Name=instance-state-name,Values=running,stopped" | grep InstanceId | grep -E -o "i\-[0-9A-Za-z]+")

	if [ "x$instance" == "x" ]; then
		instance="i-nonexist"
	fi
}

# public
status ()
{
	getinstance
	aws ec2 describe-instances --instance-ids $instance
}

# public
start ()
{
	echo "Starting instance..."
	aws ec2 run-instances --image-id $imageid --count 1 --instance-type $instance_type --key-name $key_name --security-groups $security_group > /dev/null 2>&1

	# wait for a public ip
	while true; do

		echo "Waiting $wait_seconds seconds for IP..."
		sleep $wait_seconds
		getip
		if [ ! -z "$ip" ]; then
			break
		else
			echo "Not found yet. Waiting for $wait_seconds more seconds."
			sleep $wait_seconds
		fi

	done

	echo "Found IP $ip - Starting tunnel on port $port"

	connect
}

# public
stop ()
{
	getinstance

	aws ec2 stop-instances --instance-ids $instance
}

# public
terminate ()
{
	getinstance

	aws ec2 terminate-instances --instance-ids $instance
}

# public
resume ()
{
	getip

	connect
}

# public
instruct ()
{
	echo "Please provide an argument: start, stop, resume"
}


#-------------------------------------------------------

# "main"
case "$1" in
	status)
		status
		;;
	start)
		start
		;;
	resume)
		resume
		;;
	stop)
		stop
		;;
	terminate)
		terminate
		;;
	help|*)
		instruct
		;;
esac