Script to print Riak ring ownership information

riak_ring.erl

%% Script to print out Riak ring ownership.
%% Copy/paste into Erlang shell attached to a riak cluster (riak-admin attach).
%% Remember to use: CTRL-D to dettach from the shell once done.

fun() ->
        {ok, Ring} = riak_core_ring_manager:get_my_ring(),
        Owners = riak_core_ring:all_members(Ring),
        Indices = riak_core_ring:all_owners(Ring),
        RingSize = length(Indices),
        Names = lists:zip(Owners, lists:seq(1, length(Owners))),
        io:format("~36..=s Nodes ~36..=s~n", ["", ""]),
        [begin
             NodeIndices = [Idx || {Idx,Owner} <- Indices,
                                   Owner =:= Node],
             RingPercent = length(NodeIndices) * 100 / RingSize,
             io:format("Node #~b: ~5.1f%   ~s~n",
                       [Name, RingPercent, Node])
         end || {Node, Name} <- Names],
        Ownership =
            [orddict:fetch(Owner, Names) || {_Idx, Owner} <- Indices],
        io:format("~36..=s Ring ~37..=s~n", ["", ""]),
        io:format("~p~n", [Ownership])
end().