#!/bin/bash

IPTABLES_SAVE="$( iptables-save 2> /dev/null )"
KUBECTL_ALL_PODS=$( kubectl get pods --all-namespaces -o wide | sed "s/  */ /g" )

# find all rules for "CNI-HOSTPORT-DNAT"
CHAINS_CNI_HOSTPORT_DNAT=$( echo "$IPTABLES_SAVE" | grep -e "^-A CNI-HOSTPORT-DNAT" )
echo "$CHAINS_CNI_HOSTPORT_DNAT" | while read chain || [[ -n $chain ]];
do
  # find all targets
  TARGET=$( echo $chain | cut -d " " -f 18 )
  echo "$TARGET" | while read target || [[ -n $target ]];
  do
    # search for all the targets and just use the one containing "--to-destination"
    ALL_DESTINATION_RULES=$( echo "$IPTABLES_SAVE" | grep -e "^-A $target")
    TO_DESTINATION_RULE=$( echo "$IPTABLES_SAVE" | grep -e "^-A $target.*--to-destination" )
    echo "$TO_DESTINATION_RULE" | while read rule || [[ -n $rule ]];
    do
      echo "rule: $rule"
      HOST_PORTS=$( echo "$rule" | cut -d " " -f 8 | tr ',' ' ' )
      TO_DESTINATION_RULE_ADDRESS_PORT=$( echo "$rule" | cut -d " " -f 12)
      CONTAINER_ADDRESS=$( echo "$TO_DESTINATION_RULE_ADDRESS_PORT" | cut -d ":" -f 1 )
      CONTAINER_PORT=$( echo "$TO_DESTINATION_RULE_ADDRESS_PORT" | cut -d ":" -f 2 )
      echo "hostport: $HOST_PORT container address: $CONTAINER_ADDRESS port: $CONTAINER_PORT"
      # check whether there is a pod with that address
      POD=$( echo "$KUBECTL_ALL_PODS" | grep $CONTAINER_ADDRESS | cut -d " " -f 2 )
      NAMESPACE=$( echo "$KUBECTL_ALL_PODS" | grep $CONTAINER_ADDRESS | cut -d " " -f 1 )
      POD_COUNT=$( echo "$POD" | wc -c )
      if [[ "$POD_COUNT" == "1" ]]
      then
        echo "#No pod found for address $CONTAINER_ADDRESS deleting iptables rules"
        echo "$ALL_DESTINATION_RULES" | while read deleteRule || [[ -n $deleteRule ]];
        do
          echo "iptables -t nat -D ${deleteRule#-A }"
          #iptables -t nat -D "${to_delete_rule#-A }"
        done
        echo "iptables -t nat -D ${chain#-A }"
        #iptables -t nat -D ${chain#-A }
      else
        echo "The pod $POD actually exists in namespace $NAMESPACE"
      fi
    done
  done
done

#k get pod nginx -n troubleshoot -o jsonpath="{$.spec.containers[*].ports[*].containerPort}"