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%%%-------------------------------------------------------------------
%%% @author Guido <agx@bogon.m.sigxcpu.org>
%%% @copyright (C) 2015, Guido Günther
%%% @doc
%%%
%%% @end
%%% Created : 30 Aug 2015 by Guido <agx@bogon.m.sigxcpu.org>
%%%-------------------------------------------------------------------
-module(simplec_hostsfile).
-behaviour(gen_server).
-include("simplec.hrl").
%% API
-export([start_link/1,
write/2]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-define(SERVER, ?MODULE).
-record(state, {config}).
%%%===================================================================
%%% API
%%%===================================================================
%%--------------------------------------------------------------------
%% @doc
%% Starts the server
%%
%% @spec start_link() -> {ok, Pid} | ignore | {error, Error}
%% @end
%%--------------------------------------------------------------------
start_link(Config) ->
gen_server:start_link({local, ?SERVER}, ?MODULE, Config, []).
%%--------------------------------------------------------------------
%% @doc
%% Writes out the hosts
%% @end
%%--------------------------------------------------------------------
write(Hosts, Url) ->
gen_server:cast(simplec_hostsfile, [{hosts, Hosts}, {url, Url}]).
%%%===================================================================
%%% gen_server callbacks
%%%===================================================================
%%--------------------------------------------------------------------
%% @private
%% @doc
%% Initializes the server
%%
%% @spec init(Args) -> {ok, State} |
%% {ok, State, Timeout} |
%% ignore |
%% {stop, Reason}
%% @end
%%--------------------------------------------------------------------
init(Config=#config{uris=Uris}) ->
State = #state{config=Config},
% Make sure the file exists and has no stale state
[ write_hostsfile([{hosts, []}, {url, U}], State) || U <- Uris ],
{ok, State}.
%%--------------------------------------------------------------------
%% @private
%% @doc
%% Handling call messages
%%
%% @spec handle_call(Request, From, State) ->
%% {reply, Reply, State} |
%% {reply, Reply, State, Timeout} |
%% {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, Reply, State} |
%% {stop, Reason, State}
%% @end
%%--------------------------------------------------------------------
handle_call(_Request, _From, State) ->
Reply = ok,
{reply, Reply, State}.
%%--------------------------------------------------------------------
%% @private
%% @doc
%% Handling cast messages
%%
%% @spec handle_cast(Msg, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% @end
%%--------------------------------------------------------------------
handle_cast(Args, State) ->
write_hostsfile(Args, State),
{noreply, State}.
%%--------------------------------------------------------------------
%% @private
%% @doc
%% Handling all non call/cast messages
%%
%% @spec handle_info(Info, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% @end
%%--------------------------------------------------------------------
handle_info(_Info, State) ->
{noreply, State}.
%%--------------------------------------------------------------------
%% @private
%% @doc
%% This function is called by a gen_server when it is about to
%% terminate. It should be the opposite of Module:init/1 and do any
%% necessary cleaning up. When it returns, the gen_server terminates
%% with Reason. The return value is ignored.
%%
%% @spec terminate(Reason, State) -> void()
%% @end
%%--------------------------------------------------------------------
terminate(_Reason, _State) ->
ok.
%%--------------------------------------------------------------------
%% @private
%% @doc
%% Convert process state when code is changed
%%
%% @spec code_change(OldVsn, State, Extra) -> {ok, NewState}
%% @end
%%--------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%%===================================================================
%%% Internal functions
%%%===================================================================
write_line(Host, Addr) ->
write_line(Host, Addr, []).
write_line(_Host, [], Aggr) ->
Aggr;
write_line(Host, [H|T], Aggr) ->
write_line(Host, T, [io_lib:format("~s ~s~n",[H,Host])|Aggr]).
write_hostsfile([{hosts, Hosts}, {url, Url}], #state{config=Config}) ->
File = filename:join(Config#config.dir,
"libvirt-" ++ http_uri:encode(Url) ++ ".hosts"),
TmpFile = File ++ [".tmp"],
Data = [ write_line(Host, Addrs) || {Host, Addrs} <- Hosts ],
file:write_file(TmpFile, Data),
file:rename(TmpFile, File).
|
