add inventory example for kubernetes

[gadelkareem]

Yeah really good job with this wonderful app! An example use case would be updating firewall rules on all nodes, so you allow all traffic between nodes.

version: 0.4

env:
  NODE_IPS: $(kubectl get nodes -o jsonpath={.items[*].status.addresses[?\(@.type==\"InternalIP\"\)].address})

networks:
  prod:
    inventory: for i in $(kubectl get nodes -o jsonpath={.items[*].status.addresses[?\(@.type==\"InternalIP\"\)].address}); do echo "ubuntu@$i"; done

commands:
  nodeips:
    run: >
     sudo ufw --force reset;
     sudo ufw default deny incoming;
     sudo ufw default allow outgoing;
     for i in $NODE_IPS; do sudo ufw allow from $i comment "node IP"; done;
     sudo ufw --force enable;

  mytest:
    run: echo $NODE_IPS

  ufwstatus:
    run: sudo ufw status

[VojtechVitek]

That makes sense, cool!