Cheap and easy NAT instance

gistfile1.txt

# Inspired from here: https://www.kabisa.nl/tech/cost-saving-with-nat-instances/
NatInstance:
  Type: AWS::EC2::Instance
  Properties:
    InstanceType: t4g.micro
    ImageId: ami-0a1eddae0b7f0a79f # Amazon Linux 2 AMI (HVM), SSD Volume Type, 64-bit ARM
    SourceDestCheck: false
    NetworkInterfaces:
      - AssociatePublicIpAddress: true
        DeviceIndex: "0"
        GroupSet:
          - { Fn::GetAtt: [vpc, DefaultSecurityGroup] }
        SubnetId:
          Ref: "subnetPublic1"
    UserData:
      Fn::Base64: !Sub |
        #!/bin/bash -xe
        sudo sysctl -w net.ipv4.ip_forward=1
        sudo /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE