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kaltakalta
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Added server events support
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‎src/nkdocker_events.erl‎

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%% -------------------------------------------------------------------
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%%
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%% Copyright (c) 2016 Carlos Gonzalez Florido. All Rights Reserved.
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%%
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%% This file is provided to you under the Apache License,
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%% Version 2.0 (the "License"); you may not use this file
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%% except in compliance with the License. You may obtain
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%% a copy of the License at
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%%
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%% http://www.apache.org/licenses/LICENSE-2.0
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%%
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%% Unless required by applicable law or agreed to in writing,
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%% software distributed under the License is distributed on an
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%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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%% KIND, either express or implied. See the License for the
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%% specific language governing permissions and limitations
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%% under the License.
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%%
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%% -------------------------------------------------------------------
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-module(nkdocker_events).
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-author('Carlos Gonzalez <[email protected]>').
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-behaviour(gen_server).
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-export([register/2, unregister/2, start_link/2, find/1]).
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-export([init/1, terminate/2, code_change/3, handle_call/3,
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handle_cast/2, handle_info/2]).
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-export_type([id/0, event/0]).
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-define(LLOG(Type, Txt, Args), lager:Type("NkDOCKER Events "++Txt, Args)).
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-callback nkdocker_event(id(), event()) ->
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ok.
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%% ===================================================================
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%% Types
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%% ===================================================================
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-type id() :: {inet:ip_address(), inet:port()}.
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-type event() :: {Status::atom(), Id::binary(), From::binary(), Time::integer()}.
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%% ===================================================================
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%% Public
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%% ===================================================================
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%% @doc Registers a server to listen to docker events
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%% For each new event, Callback:nkdocker_event(event()) will be called
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%% The first caller for a specific ip and port daemon will start the server
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-spec register(nkdocker:conn_opts(), module()) ->
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{ok, pid()} | {error, term()}.
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register(Opts, Callback) ->
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case find(Opts) of
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{ok, Id, not_found} ->
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case nkdocker_sup:start_events(Id, Opts) of
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{ok, Pid} ->
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gen_server:call(Pid, {register, Callback});
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{error, Error} ->
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{error, Error}
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end;
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{ok, _Id, Pid} ->
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gen_server:call(Pid, {register, Callback});
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{error, Error} ->
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{error, Error}
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end.
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%% @doc Unregisters a callback
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%% After the last callback is unregistered, the server stops
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unregister(Opts, Callback) ->
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case find(Opts) of
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{ok, _Id, not_found} ->
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ok;
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{ok, _Id, Pid} ->
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gen_server:cast(Pid, {unregister, Callback});
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{error, Error} ->
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{error, Error}
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end.
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%% @private
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start_link(Id, Opts) ->
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gen_server:start_link(?MODULE, [Id, Opts], []).
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%% @private
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find(Opts) ->
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case nkdocker_server:get_conn(Opts) of
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{ok, {Ip, #{port:=Port}}} ->
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Id = {Ip, Port},
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case nklib_proc:values({?MODULE, Id}) of
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[] ->
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{ok, Id, not_found};
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[{_, Pid}] ->
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{ok, Id, Pid}
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end;
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{error, Error} ->
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{error, Error}
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end.
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% ===================================================================
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%% gen_server behaviour
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%% ===================================================================
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-record(state, {
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id :: id(),
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server :: pid(),
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ref :: reference(),
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regs = [] :: [module()]
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}).
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%% @private
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-spec init(term()) ->
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{ok, tuple()} | {ok, tuple(), timeout()|hibernate} |
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{stop, term()} | ignore.
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init([Id, Opts]) ->
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true = nklib_proc:reg({?MODULE, Id}),
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case nkdocker_server:start_link(Opts) of
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{ok, Pid} ->
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case nkdocker:events(Pid) of
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{async, Ref} ->
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Regs = nkdocker_app:get(events_callbacks, []),
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case Regs of
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[] -> ok;
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_ -> ?LLOG(warning, "recovered callbacks: ~p", [Regs])
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end,
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{ok, #state{id=Id, server=Pid, ref=Ref, regs=Regs}};
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{error, Error} ->
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{stop, Error}
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end;
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{error, Error} ->
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{stop, Error}
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end.
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%% @private
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-spec handle_call(term(), {pid(), term()}, #state{}) ->
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{noreply, #state{}} | {reply, term(), #state{}} |
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{stop, Reason::term(), #state{}} | {stop, Reason::term(), Reply::term(), #state{}}.
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handle_call({register, Module}, _From, #state{regs=Regs}=State) ->
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Regs2 = nklib_util:store_value(Module, Regs),
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nkdocker_app:put(events_callbacks, Regs2),
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{reply, {ok, self()}, State#state{regs=Regs2}};
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handle_call(state, _From, State) ->
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{reply, State, State};
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handle_call(Msg, _From, State) ->
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lager:error("Module ~p received unexpected call ~p", [?MODULE, Msg]),
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{noreply, State}.
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%% @private
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-spec handle_cast(term(), #state{}) ->
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{noreply, #state{}} | {stop, term(), #state{}}.
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handle_cast({unregister, Module}, #state{regs=Regs}=State) ->
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case Regs -- [Module] of
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[] ->
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{stop, normal, State};
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Regs2 ->
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nkdocker_app:put(events_callbacks, Regs2),
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{noreply, State#state{regs=Regs2}}
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end;
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handle_cast(Msg, State) ->
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lager:error("Module ~p received unexpected cast ~p", [?MODULE, Msg]),
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{noreply, State}.
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%% @private
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-spec handle_info(term(), #state{}) ->
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{noreply, #state{}} | {stop, term(), #state{}}.
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handle_info({nkdocker, Ref, {data, Map}}, #state{ref=Ref}=State) ->
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{noreply, event(Map, State)};
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handle_info(Info, State) ->
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lager:warning("Module ~p received unexpected info: ~p (~p)", [?MODULE, Info, State]),
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{noreply, State}.
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%% @private
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-spec code_change(term(), #state{}, term()) ->
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{ok, #state{}}.
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code_change(_OldVsn, State, _Extra) ->
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{ok, State}.
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%% @private
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-spec terminate(term(), #state{}) ->
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ok.
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terminate(Reason, _State) ->
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case Reason of
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normal ->
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?LLOG(notice, "server stop normal", []),
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nkdocker_app:put(events_callbacks, []);
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_ ->
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?LLOG(notice, "server stop anormal: ~p", [Reason]),
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ok
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end,
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ok.
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% ===================================================================
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%% Internal
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%% ===================================================================
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event(#{<<"status">>:=Status, <<"id">>:=Id, <<"time">>:=Time}=Msg, State) ->
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From = maps:get(<<"from">>, Msg, <<>>),
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Event = {binary_to_atom(Status, latin1), Id, From, Time},
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#state{id=ServerId, regs=Regs} = State,
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lists:foreach(
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fun(Module) ->
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case catch Module:nkdocker_event(ServerId, Event) of
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ok ->
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ok;
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Error ->
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?LLOG(warning, "error calling ~p: ~p", [Module, Error])
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end
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end,
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Regs),
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State;
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event(Event, State) ->
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lager:notice("Unrecognized event: ~p", [Event]),
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State.
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‎src/nkdocker_sup.erl‎

Lines changed: 24 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -23,7 +23,30 @@
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-author('Carlos Gonzalez <[email protected]>').
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-behaviour(supervisor).
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-export([init/1, start_link/0]).
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-export([start_events/2, init/1, start_link/0]).
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% -include("nkmedia.hrl").
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start_events(Id, Opts) ->
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Spec = {
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{events, Id},
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{nkdocker_events, start_link, [Id, Opts]},
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permanent,
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5000,
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worker,
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[nkdocker_events]
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},
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case supervisor:start_child(?MODULE, Spec) of
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{ok, Pid} ->
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{ok, Pid};
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{error, already_present} ->
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ok = supervisor:delete_child(?MODULE, {events, Id}),
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start_events(Id, Opts);
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{error, {already_started, Pid}} ->
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{ok, Pid};
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{error, Error} ->
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{error, Error}
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end.
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%% @private

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