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cdk-jump-box

Connecting

First you'll need to do the bootstrapping steps described below.

STACK_NAME="MyStack"
ASG_NAME="${STACK_NAME}Jump"

SSH_KEY_NAME="$HOME/.ssh/${AWS_PROFILE}-${ASG_NAME}.pem"

# Set us up the Jumpbox
aws autoscaling set-desired-capacity --auto-scaling-group-name "$ASG_NAME" --desired-capacity 1

# Find the jump box instance
while
  JUMP_INSTANCE_ID=$(aws autoscaling describe-auto-scaling-groups --query "AutoScalingGroups[?AutoScalingGroupName=='$ASG_NAME'].Instances[].InstanceId" --output=text)
  [[ -z "$JUMP_INSTANCE_ID" ]];
do
  sleep 10
done

LOCAL_PORT=$(python -c 'import socket; s=socket.socket(); s.bind(("", 0)); print(s.getsockname()[1]); s.close()')

ssh -f -i "$SSH_KEY" -L "$LOCAL_PORT:$INTERNAL_HOST:$INTERNAL_PORT" "ec2-user@$JUMP_INSTANCE_ID" sleep 10 && \
exampleClient --host localhost --port "$LOCAL_PORT" ...

Bootstrapping

You only have to run these steps once, but you need to do it before you try connecting.

  1. Install the session manager plugin:
# On a Mac, you may need to allow this in System Preferences -> Security
brew install session-manager-plugin
  1. Make sure the following is in your ~/.ssh/config:
# SSH over Session Manager
Host i-* mi-*
  ProxyCommand sh -c "aws ssm start-session --target %h --document-name AWS-StartSSHSession --parameters 'portNumber=%p'"
  # Keep connection from closing on you due to agressive SSM timeouts, but close it when the other side stops caring
  TCPKeepAlive yes
  ServerAliveInterval 15
  # Never Forward agents to remove machines you don't know
  ForwardAgent no
  # If you need to scp or portforward a lot, using a control channle will help.  Be sure to create the ControlPath first
  # ControlMaster auto
  # ControlPath ~/.ssh/control/%C
  # ControlPersist 30

  1. Get the SSH key such as ~/.ssh/myAccount-MyStackJump.pem:
export AWS_PROFILE=myAccount
export AWS_REGION=us-west-2
click a

STACK_NAME="MyStack"
ASG_NAME="${STACK_NAME}Jump"

# Fetch the SSH key from SecretsManager
SSH_KEY_NAME="$HOME/.ssh/${AWS_PROFILE}-${ASG_NAME}.pem"
aws secretsmanager get-secret-value --region="$AWS_REGION" --output=text --query SecretString --secret-id "ec2-ssh-key/${ASG_NAME}/private" > "$SSH_KEY_NAME"
chmod 400 "$SSH_KEY_NAME"