SSH bastion lookup

bastion

#!/usr/bin/env bash

set -e          # exit on command errors
set -o nounset  # abort on unbound variable
set -o pipefail # capture fail exit codes in piped commands
# set -x

# Config:
# ~/.ssh/config
# Host i-*
#        ProxyCommand bastion %h %p
# Usage:
# ssh ec2-user@instanceID

BASTION=''
DOMAIN='yadayada.com'

REPLY=$(aws ec2 describe-instances --instance-ids "$1")

ENVIRONMENT=$(echo "$REPLY" | jq -r '.Reservations[].Instances[].Tags[] | if .Key == "Environment" then .Value else empty end')

# Replace bastion lookup logic to fit your naming scheme.
if [[ $ENVIRONMENT == "prod" ]]; then
        BASTION="prod-bastion.$DOMAIN"
else
        BASTION="$ENVIRONMENT-bastion.$DOMAIN"
fi

PRIVATEDNS=$(echo "$REPLY" | jq -r '.Reservations[].Instances[].PrivateDnsName')

ssh -q admin@"$BASTION" -W "$PRIVATEDNS":"$2"