def list(self):
        """
        Sub-command list.

        Takes no further parameters. Will discover the current configuration
        and print a table of all the nodes with status and port.
        """
        self.discover()
        print_docs = []

        # mongos
        for node in sorted(self.get_tagged(['mongos'])):
            doc = OrderedDict([('process', 'mongos'), ('port', node),
                              ('status', 'running'
                               if self.cluster_running[node] else 'down')])
            print_docs.append(doc)

        if len(self.get_tagged(['mongos'])) > 0:
            print_docs.append(None)

        # configs
        for node in sorted(self.get_tagged(['config'])):
            doc = OrderedDict([('process', 'config server'),
                              ('port', node),
                              ('status', 'running'
                               if self.cluster_running[node] else 'down')])
            print_docs.append(doc)

        if len(self.get_tagged(['config'])) > 0:
            print_docs.append(None)

        # mongod
        for shard in self._get_shard_names(self.loaded_args):
            tags = []
            replicaset = ('replicaset' in self.loaded_args and
                          self.loaded_args['replicaset'])
            padding = ''

            if shard:
                print_docs.append(shard)
                tags.append(shard)
                padding = '    '

            if replicaset:
                # primary
                primary = self.get_tagged(tags + ['primary', 'running'])
                if len(primary) > 0:
                    node = list(primary)[0]
                    print_docs.append(OrderedDict
                                      ([('process', padding + 'primary'),
                                        ('port', node),
                                        ('status', 'running'
                                         if self.cluster_running[node]
                                         else 'down')]))

                # secondaries
                secondaries = self.get_tagged(tags + ['secondary', 'running'])
                for node in sorted(secondaries):
                    print_docs.append(OrderedDict
                                      ([('process', padding + 'secondary'),
                                        ('port', node),
                                        ('status', 'running'
                                         if self.cluster_running[node]
                                         else 'down')]))

                # data-bearing nodes that are down or not in the
                # replica set yet
                mongods = self.get_tagged(tags + ['mongod'])
                arbiters = self.get_tagged(tags + ['arbiter'])

                nodes = sorted(mongods - primary - secondaries - arbiters)
                for node in nodes:
                    print_docs.append(OrderedDict
                                      ([('process', padding + 'mongod'),
                                        ('port', node),
                                        ('status', 'running'
                                         if self.cluster_running[node]
                                         else 'down')]))

                # arbiters
                for node in arbiters:
                    print_docs.append(OrderedDict
                                      ([('process', padding + 'arbiter'),
                                        ('port', node),
                                        ('status', 'running'
                                         if self.cluster_running[node]
                                         else 'down')]))

            else:
                nodes = self.get_tagged(tags + ['mongod'])
                if len(nodes) > 0:
                    node = nodes.pop()
                    print_docs.append(OrderedDict
                                      ([('process', padding + 'single'),
                                        ('port', node),
                                        ('status', 'running'
                                         if self.cluster_running[node]
                                         else 'down')]))
            if shard:
                print_docs.append(None)

        processes = self._get_processes()
        startup = self.startup_info

        # print tags as well
        for doc in [x for x in print_docs if type(x) == OrderedDict]:
            try:
                doc['pid'] = processes[doc['port']].pid
            except KeyError:
                doc['pid'] = '-'

            if self.args['verbose'] or self.args['tags']:
                tags = self.get_tags_of_port(doc['port'])
                doc['tags'] = ', '.join(tags)

            if self.args['startup']:
                try:
                    # first try running process (startup may be modified
                    # via start command)
                    doc['startup command'] = ' '.join(processes[doc['port']]
                                                      .cmdline())
                except KeyError:
                    # if not running, use stored startup_info
                    doc['startup command'] = startup[str(doc['port'])]

        print_docs.append(None)
        print()
        print_table(print_docs)
        if self.loaded_args.get('auth'):
            print('\tauth: "%s:%s"' % (self.loaded_args.get('username'),
                                       self.loaded_args.get('password')))
Sub-command list.

        Takes no further parameters. Will discover the current configuration
        and print a table of all the nodes with status and port.