def call(Map config) {

    def defaultConfig = [
        volthaNamespace: "voltha",
        stackName: "voltha",
        adaptersToWait: 2,
    ]

    if (!config) {
        config = [:]
    }

    def cfg = defaultConfig + config

    if (cfg.adaptersToWait == 0){
       //no need to wait
       println "No need to wait for adapters to be registered"
       return
    }

    println "Wait for adapters to be registered"

    // guarantee that at least the specified number of adapters are registered with VOLTHA before proceeding
     sh """
        set +x
        _TAG="voltha-voltha-api" bash -c "while true; do kubectl port-forward --address 0.0.0.0 -n ${cfg.volthaNamespace} svc/${cfg.stackName}-voltha-api 55555:55555; done"&
       """

    sh """
        set +x
        adapters=\$(voltctl adapter list -q | wc -l)
        while [[ \$adapters -lt ${cfg.adaptersToWait} ]]; do
          sleep 5
          adapters=\$(voltctl adapter list -q | wc -l)
        done
    """

    // NOTE that we need to wait for LastCommunication to be equal or shorter that 5s
    // as that means the core can talk to the adapters
    // if voltctl can't read LastCommunication we skip this check
    def done = false;

    while (!done) {
      sleep 1
      def adapters = ""
      try {
        adapters = sh (
          script: 'voltctl adapter list --format "{{gosince .LastCommunication}}"',
          returnStdout: true,
        ).trim()
      } catch (err) {
        // in some older versions of voltctl the command results in
        // ERROR: Unexpected error while attempting to format results as table : template: output:1: function "gosince" not defined
        // if that's the case we won't be able to check the timestamp so it's useless to wait
        println("voltctl can't parse LastCommunication, skip waiting")
        done = true
        break
      }

      def waitingOn = adapters.split( '\n' ).find{since ->
        since = since.replaceAll('s','') //remove seconds from the string

        // it has to be a single digit
        if (since.length() > 1) {
            return true
        }
        if ((since as Integer) > 5) {
            return true
        }
        return false
      }
      done = (waitingOn == null || waitingOn.length() == 0)
    }

    sh """
      set +x
      ps aux | grep port-forw | grep -v grep | awk '{print \$2}' | xargs --no-run-if-empty kill -9 || true
    """
}