SSM Instance Connect

README.md

1. Copy the file ssm-connect to a folder in your path
2. Run ssm-connect setup, it will create a new SSH key-pair and configure SSH config
3. Use it like ssh user@i-1234567890

ssm-connect

#!/bin/bash -e

setup() {

ssh-keygen -t rsa -m PEM -N '' -f ${HOME}/.ssh/ssm-connect-rsa
chmod 600 ${HOME}/.ssh/ssm-connect-rsa

cat - ${HOME}/.ssh/config <<EOF > ${HOME}/.ssh/config_temp
# SSH over Session Manager
Host i-* mi-*
	StrictHostKeyChecking no
	UserKnownHostsFile=/dev/null
	User ec2-user
	IdentityFile ${HOME}/.ssh/ssm-connect-rsa
	ProxyCommand sh -c "ssm-connect connect %h %r %p"

EOF

cat ${HOME}/.ssh/config_temp > ${HOME}/.ssh/config
rm -f ${HOME}/.ssh/config_temp

}

connect() {
INSTANCE_ID=$1
TARGET_USER=$2
TARGET_PORT=$3

AZ=$(aws ec2 describe-instances --instance-ids ${INSTANCE_ID} --query "Reservations[0].Instances[0].Placement.AvailabilityZone" --output text)

aws ec2-instance-connect send-ssh-public-key --instance-id ${INSTANCE_ID} --instance-os-user ${TARGET_USER} --availability-zone ${AZ} --ssh-public-key file://${HOME}/.ssh/ssm-connect-rsa.pub > /dev/null

exec aws ssm start-session --target ${INSTANCE_ID} --document-name AWS-StartSSHSession --parameters "portNumber=${TARGET_PORT}"
}

CMD=${1:?Missing command}

case $CMD in
	setup*)
		setup
		;;
	connect*)
		connect $2 $3 $4
		;;
	*)
		# unknown
		echo "Usage: ssm-connect setup"
		;;
esac