decides how to invoke a module

def _executor_internal_inner(self, host, module_name, module_args, inject, port, is_chained=False):
        ''' decides how to invoke a module '''

        # allow module args to work as a dictionary
        # though it is usually a string
        new_args = ""
        if type(module_args) == dict:
            for (k,v) in module_args.iteritems():
                new_args = new_args + "%s='%s' " % (k,v)
            module_args = new_args

        module_name = utils.template(self.basedir, module_name, inject)
        module_args = utils.template(self.basedir, module_args, inject, expand_lists=True)

        if module_name in utils.plugins.action_loader:
            if self.background != 0:
                raise errors.AnsibleError("async mode is not supported with the %s module" % module_name)
            handler = utils.plugins.action_loader.get(module_name, self)
        elif self.background == 0:
            handler = utils.plugins.action_loader.get('normal', self)
        else:
            handler = utils.plugins.action_loader.get('async', self)

        conditional = utils.template(self.basedir, self.conditional, inject)
        if not getattr(handler, 'BYPASS_HOST_LOOP', False) and not utils.check_conditional(conditional):
            result = utils.jsonify(dict(skipped=True))
            self.callbacks.on_skipped(host, inject.get('item',None))
            return ReturnData(host=host, result=result)

        conn = None
        actual_host = inject.get('ansible_ssh_host', host)
        actual_port = port
        if self.transport in [ 'paramiko', 'ssh' ]:
            actual_port = inject.get('ansible_ssh_port', port)

        # the delegated host may have different SSH port configured, etc
        # and we need to transfer those, and only those, variables
        delegate_to = inject.get('delegate_to', None)
        if delegate_to is not None:
            delegate_to = utils.template(self.basedir, delegate_to, inject)
            inject = inject.copy()
            interpreters = []
            for i in inject:
                if i.startswith("ansible_") and i.endswith("_interpreter"):
                    interpreters.append(i)
            for i in interpreters:
                del inject[i]
            port = C.DEFAULT_REMOTE_PORT
            try:
                delegate_info = inject['hostvars'][delegate_to]
                actual_host = delegate_info.get('ansible_ssh_host', delegate_to)
                actual_port = delegate_info.get('ansible_ssh_port', port)
                for i in delegate_info:
                    if i.startswith("ansible_") and i.endswith("_interpreter"):
                        inject[i] = delegate_info[i]
            except errors.AnsibleError:
                actual_host = delegate_to
                actual_port = port

        try:
            if actual_port is not None:
                actual_port = int(actual_port)
        except ValueError, e:
            result = dict(failed=True, msg="FAILED: Configured port \"%s\" is not a valid port, expected integer" % actual_port)
            return ReturnData(host=host, comm_ok=False, result=result)

        try:
            conn = self.connector.connect(actual_host, actual_port)
            if delegate_to or host != actual_host:
                conn.delegate = host


        except errors.AnsibleConnectionFailed, e:
            result = dict(failed=True, msg="FAILED: %s" % str(e))
            return ReturnData(host=host, comm_ok=False, result=result)

        tmp = ''
        # all modules get a tempdir, action plugins get one unless they have NEEDS_TMPPATH set to False
        if getattr(handler, 'NEEDS_TMPPATH', True):
            tmp = self._make_tmp_path(conn)

        result = handler.run(conn, tmp, module_name, module_args, inject)

        conn.close()

        if not result.comm_ok:
            # connection or parsing errors...
            self.callbacks.on_unreachable(host, result.result)
        else:
            data = result.result
            if 'item' in inject:
                result.result['item'] = inject['item']

            result.result['invocation'] = dict(
                module_args=module_args,
                module_name=module_name
            )

            if is_chained:
                # no callbacks
                return result
            if 'skipped' in data:
                self.callbacks.on_skipped(host)
            elif not result.is_successful():
                ignore_errors = self.module_vars.get('ignore_errors', False)
                self.callbacks.on_failed(host, data, ignore_errors)
            else:
                self.callbacks.on_ok(host, data)
        return result