resolve some sort of name for an aws interface id

resolveInterface.sh

#!/bin/bash
# todo - add a cache so it will not have to query repeat eni ids

instanceId=""
instanceName=""
interfaceInfo=""
exitcode=""
declare -A cache=()

interfaceId=$1
if [ ${cache[${interfaceId}]} ]; then
  instanceName="${cache[${interfaceId}]}"
else
  interfaceInfo=$(aws ec2 describe-network-interfaces --network-interface-id $interfaceId 2> /dev/null)
  exitcode=$?
  if [[ "$exitcode" == "0" ]]; then
    if [[ "$interfaceInfo" != "" ]]; then
      instanceId=$(echo $interfaceInfo | jq -r '.NetworkInterfaces[0].Attachment.InstanceId')
      if [[ "$instanceId" == "null" ]]; then
        instanceName=$(echo $interfaceInfo | jq -r '.NetworkInterfaces[0].Description')
      else
        instanceName=$(aws ec2 describe-instances --instance-ids $instanceId | jq -r '.Reservations[0].Instances[0] | (.Tags[] | select(.Key=="Name") | .Value)' 2> /dev/null)
        if [[ "$?" != "0" || "$instanceName" == "" ]]; then
          instanceName=$instanceId
        fi
      fi
    else
      instanceName="nullJson"
    fi
  elif [[ "$exitcode" == "255" ]]; then
    instanceName="InterfaceNotFound"
  else
    instanceName="UnknownError"
  fi
  cache+=(["$interfaceId"]="$instanceName")
fi
echo $interfaceId $instanceName