ekka

%%--------------------------------------------------------------------
%% Copyright (c) 2019 EMQ Technologies Co., Ltd. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%--------------------------------------------------------------------

-module(ekka_cluster_dns).

-behaviour(ekka_cluster_strategy).

-import(proplists, [get_value/2]).

%% Cluster strategy callbacks
-export([ discover/1
        , lock/1
        , unlock/1
        , register/1
        , unregister/1
        ]).

discover(Options) ->
    Name = get_value(name, Options),
    App  = get_value(app, Options),
    {ok, [node_name(App, IP) || IP <- inet_res:lookup(Name, in, a)]}.

node_name(App, IP) ->
    list_to_atom(App ++ "@" ++ inet:ntoa(IP)).

lock(_Options) ->
    ignore.

unlock(_Options) ->
    ignore.

register(_Options) ->
    ignore.

unregister(_Options) ->
    ignore.