riaknostic_check_ring_membership.erl

%% -------------------------------------------------------------------
%%
%% riaknostic - automated diagnostic tools for Riak
%%
%% Copyright (c) 2011 Basho Technologies, Inc.  All Rights Reserved.
%%
%% This file is provided to you 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.
%%
%% -------------------------------------------------------------------

%% @doc Diagnostic that checks whether the local node is a member of
%% the ring. This might arise when the node name in vm.args has
%% changed but the node has not been renamed in the ring.
-module(riaknostic_check_ring_membership).
-behaviour(riaknostic_check).

-export([description/0,
         valid/0,
         check/0,
         format/1]).

-include_lib("eunit/include/eunit.hrl").

-spec description() -> string().
description() ->
    "Cluster membership validity".

-spec valid() -> boolean().
valid() ->
    riaknostic_node:can_connect().

-spec check() -> [{lager:log_level(), term()}].
check() ->
    Stats = riaknostic_node:stats(),
    {ring_members, RingMembers} = lists:keyfind(ring_members, 1, Stats),
    {nodename, NodeName} = lists:keyfind(nodename, 1, Stats),
    case lists:member(NodeName, RingMembers) of
        true ->
            [];
        false ->
            [{warning, {not_ring_member, NodeName}}]
    end.

check_test() ->
    meck:new(riaknostic_node, [passthrough]),
    meck:expect(riaknostic_node, stats, fun() -> [{ring_members, ["riak@127.0.0.1"]}, {nodename, ["notmember@127.0.0.1"]}] end),
    ?assert(meck:validate(riaknostic_node)),
    ?assertEqual([{warning, {not_ring_member, ["notmember@127.0.0.1"]}}], check()),
    ?assertNotEqual([{warning, {not_ring_member, ["notequal@127.0.0.1"]}}], check()),
    meck:unload(riaknostic_node).

-spec format(term()) -> {io:format(), [term()]}.
format({not_ring_member, Nodename}) ->
    {"Local node ~w is not a member of the ring. Please check that the -name setting in vm.args is correct.", [Nodename]}.