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

        // 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
        """
}