One Time EC2 SSH public key connect

one-time-ec2-ssh-connect.sh

#!/bin/bash

TMPKEY="my-ssh-tmp-key-${RANDOM}"
EC2USER='ec2-user'

generate_ssh_key_pair(){
    ssh-keygen -t rsa -f ~/.ssh/${TMPKEY} -N "" && \
    chmod 600 ~/.ssh/${TMPKEY}.pub
}

get_az_from_instance_id(){
    # get_az_from_instance_id iid region
    aws --region "$2" ec2 describe-instances --instance-id "$1" --query 'Reservations[0].Instances[0].Placement.AvailabilityZone' --output text
}

get_public_ip(){
    aws --region "$2" ec2 describe-instances --instance-id "$1" --query 'Reservations[0].Instances[0].NetworkInterfaces[0].Association.PublicIp' --output text
}

send_ssh_public_key(){
    aws ec2-instance-connect send-ssh-public-key --region "$1" --instance-id "$2" \
    --availability-zone "$3" \
    --instance-os-user ec2-user --ssh-public-key file://$HOME/.ssh/${TMPKEY}.pub
}

iid="$1"
region="$2"

az=$(get_az_from_instance_id $iid $region)
publicip=$(get_public_ip $iid $region)

echo "connecting to $iid at $az as $EC2USER on $publicip"
generate_ssh_key_pair && \
send_ssh_public_key $region $iid $az && \
ssh -i $HOME/.ssh/${TMPKEY} ${EC2USER}@${publicip};
echo "clean up the temp key pair"
rm -f ~/.ssh/"${TMPKEY}*" && echo "DONE"