rbeacon - LAN discovery and presence.

Copyright (c) 2014 Benoît Chesneau.

Version: 0.3.0

Description

The rbeacon module implements a peer-to-peer discovery service for local networks. A beacon can broadcast and/or capture service announcements using UDP messages on the local area network. This implementation uses IPv4 UDP broadcasts. You can define the format of your outgoing beacons, and set a filter that validates incoming beacons. Beacons are sent and received asynchronously in the background.

Note: the current implementation is heavily inspired on zbeacon from zeromq.

Usage

Look at the rbeacon module for the API usage.

Note: You can set the interface on which you broadcast using the application environment setting broadast_if or the the OS environment variable RBEACON_INTERFACE.

Example

From the rbeacon_test function:

{ok, Service} = rbeacon:new(9999),
?assert(is_pid(Service)),

ok = rbeacon:set_interval(Service, 100),
ok = rbeacon:publish(Service, <<"announcement">>),

{ok, Client} = rbeacon:new(9999),
ok = rbeacon:subscribe(Client, <<>>),

{ok, Msg, _Addr} = rbeacon:recv(Client),
?assertEqual(Msg, <<"announcement">>),
ok = rbeacon:close(Service),
ok = rbeacon:close(Client),

{ok, Node1} = rbeacon:new(5670),
{ok, Node2} = rbeacon:new(5670),
{ok, Node3} = rbeacon:new(5670),

ok = rbeacon:noecho(Node1),

rbeacon:publish(Node1, <<"Node/1">>),
rbeacon:publish(Node2, <<"Node/2">>),
rbeacon:publish(Node3, <<"GARBAGE">>),
rbeacon:subscribe(Node1, <<"Node">>),

{ok, Msg2, _Addr} = rbeacon:recv(Node1),
?assertEqual(Msg2, <<"Node/2">>),

rbeacon:close(Node1),
rbeacon:close(Node2),
rbeacon:close(Node3).

You can also receive from the beacon as message (from the rbeacon_active_test):

{ok, Service} = rbeacon:new(9999, [active, noecho]),
?assert(is_pid(Service)),

ok = rbeacon:set_interval(Service, 100),
ok = rbeacon:publish(Service, <<"announcement">>),

{ok, Client} = rbeacon:new(9999, [active]),
ok = rbeacon:subscribe(Client, <<>>),
receive
    {rbeacon, Client, <<"announcement">>, _Addr} ->
        ok
end,

ok = rbeacon:close(Service),
receive
    {rbeacon, Service, closed} -> ok
end,

ok = rbeacon:close(Client),
receive
    {rbeacon, Client, closed} -> ok
end,

{ok, Node1} = rbeacon:new(5670, [active, noecho]),
{ok, Node2} = rbeacon:new(5670, [active, noecho]),
{ok, Node3} = rbeacon:new(5670, [active, noecho]),

rbeacon:publish(Node1, <<"Node/1">>),
rbeacon:publish(Node2, <<"Node/2">>),
rbeacon:publish(Node3, <<"GARBAGE">>),
rbeacon:subscribe(Node1, <<"Node">>),

Result = loop_sub(Node1, [], 1),

?assert(lists:member(<<"Node/2">>, Result)),

rbeacon:close(Node1),
rbeacon:close(Node2),
rbeacon:close(Node3),

ok.

Ownership and License

The contributors are listed in AUTHORS. This project uses the MPL v2 license, see LICENSE.

rbeacon uses the C4.1 (Collective Code Construction Contract) process for contributions.

Development

Under C4.1 process, you are more than welcome to help us by:

• join the discussion over anything from design to code style
• try out and submit issue reports or feature requests
• pick a task in issues and get it done
• fork the repository and have your own fixes
• send us pull requests
• and even star this project ^_^

To run the test suite: $ rebar eunit

Modules

rbeacon