Using SSH agent forwarding & bastion server / jump box

ssh-agent-example.sh

# Start SSH agent
eval $(ssh-agent)

# Add specific key
ssh-add ~/.ssh/butterfly.pem

# Add default key (if needed for GitHub, etc)
ssh-add

# SSH config entries
Host butterfly-bastion
  Hostname 55.55.55.55
  User ubuntu
  IdentityFile ~/.ssh/butterfly.pem
  IdentitiesOnly yes
  ForwardAgent yes

Host butterfly-dev
  Hostname dev1.local
  User ubuntu
  ProxyJump ebutterfly-bastion
  
ssh butterfly-dev


# Auto start agent
if [ -z "$SSH_AUTH_SOCK" ] ; then
  eval $(ssh-agent)
  ssh-add
fi


# Auto stop agent 
if [ -n "$SSH_AUTH_SOCK" ] ; then
  eval `/usr/bin/ssh-agent -k`
fi


# Open SSH tunnel on from remote port 5432 to local port 5555 in background
# ssh -N -f -T -L 5555:butterfly-dev:5432 ubuntu@butterfly-dev