Return the names of the nodes composing the kubernetes cluster

    CLI Examples::

        salt '*' kubernetes.nodes
        salt '*' kubernetes.nodes kubeconfig=/etc/salt/k8s/kubeconfig context=minikube

def nodes(**kwargs):
    '''
    Return the names of the nodes composing the kubernetes cluster

    CLI Examples::

        salt '*' kubernetes.nodes
        salt '*' kubernetes.nodes kubeconfig=/etc/salt/k8s/kubeconfig context=minikube
    '''
    cfg = _setup_conn(**kwargs)
    try:
        api_instance = kubernetes.client.CoreV1Api()
        api_response = api_instance.list_node()

        return [k8s_node['metadata']['name'] for k8s_node in api_response.to_dict().get('items')]
    except (ApiException, HTTPError) as exc:
        if isinstance(exc, ApiException) and exc.status == 404:
            return None
        else:
            log.exception('Exception when calling CoreV1Api->list_node')
            raise CommandExecutionError(exc)
    finally:
        _cleanup(**cfg)