Get rid of lager and move to error_logger

Also update exometer_core because it is not using lager directly
anymore.

rebar.config

@@ -1,7 +1,4 @@
 {deps, [
         {hackney, ".*", {git, "git://github.com/benoitc/hackney.git", {branch, "master"}}},
-        %% lager dependency to override exometer's lager dependency, which does not compile on Erlang 19.
-        {lager, ".*", {git, "git://github.com/basho/lager.git", {tag, "3.2.1"}}},
-        {exometer_core, ".*", {git, "git://github.com/Feuerlabs/exometer_core.git", "5fdd9426713a3c26cae32f644a3120711b1cdb64"}}
+        {exometer_core, ".*", {git, "git://github.com/Feuerlabs/exometer_core.git", "master"}}
        ]}.
-{erl_opts, [{parse_transform, lager_transform}]}.

src/exometer_influxdb.app.src

@@ -7,7 +7,6 @@
                   kernel,
                   stdlib,
                   hackney,
-                  lager,
                   exometer_core
                  ]},
   {env, []}

src/exometer_report_influxdb.erl

@@ -120,7 +120,7 @@ exometer_init(Opts) ->
                       state()) -> callback_result().
 exometer_report(_Metric, _DataPoint, _Extra, _Value,
                 #state{connection = undefined} = State) ->
-    ?debug("InfluxDB reporter isn't connected and will reconnect."),
+    ?info("InfluxDB reporter isn't connected and will reconnect."),
     {ok, State};
 exometer_report(Metric, DataPoint, _Extra, Value,
                 #state{metrics = Metrics} = State) ->
@@ -176,8 +176,6 @@ exometer_info({exometer_influxdb, send},
               #state{precision = Precision,
                      collected_metrics = CollectedMetrics} = State) ->
     if CollectedMetrics /= #{} ->
-        ?debug("InfluxDB reporter send packet with ~p measurements",
-               [maps:size(CollectedMetrics)]),
         Packets = [make_packet(MetricName, Tags, Fileds, Timestamping, Precision) ++ "\n"
                    || {_, {MetricName, Tags, Fileds, Timestamping}} 
                       <- maps:to_list(CollectedMetrics)],

src/log.hrl

@@ -5,38 +5,15 @@
 -define(__LOG_HRL__, true).
 
 %% Lager logging levels
-%%   debug, info, notice, warning, error, critical, alert, emergency, none.
+%%   info, warning, error
 
--define(debug(Fmt), lager:debug(Fmt)).
--define(debug(Fmt, Args), lager:debug(Fmt, Args)).
--define(debug(Attrs, Fmt, Args), lager:debug(Attrs, Fmt, Args)).
+-define(info(Fmt), error_logger:info_msg(Fmt ++ "\n")).
+-define(info(Fmt, Args), error_logger:info_msg(Fmt ++ "\n", Args)).
 
--define(info(Fmt), lager:info(Fmt)).
--define(info(Fmt, Args), lager:info(Fmt, Args)).
--define(info(Attrs, Fmt, Args), lager:info(Attrs, Fmt, Args)).
+-define(warning(Fmt), error_logger:warning_msg(Fmt ++ "\n")).
+-define(warning(Fmt, Args), error_logger:warning_msg(Fmt ++ "\n", Args)).
 
--define(notice(Fmt), lager:notice(Fmt)).
--define(notice(Fmt, Args), lager:notice(Fmt, Args)).
--define(notice(Attrs, Fmt, Args), lager:notice(Attrs, Fmt, Args)).
-
--define(warning(Fmt), lager:warning(Fmt)).
--define(warning(Fmt, Args), lager:warning(Fmt, Args)).
--define(warning(Attrs, Fmt, Args), lager:warning(Attrs, Fmt, Args)).
-
--define(error(Fmt), lager:error(Fmt)).
--define(error(Fmt, Args), lager:error(Fmt, Args)).
--define(error(Attrs, Fmt, Args), lager:error(Attrs, Fmt, Args)).
-
--define(critical(Fmt), lager:critical(Fmt)).
--define(critical(Fmt, Args), lager:critical(Fmt, Args)).
--define(critical(Attrs, Fmt, Args), lager:critical(Attrs, Fmt, Args)).
-
--define(alert(Fmt), lager:alert(Fmt)).
--define(alert(Fmt, Args), lager:alert(Fmt, Args)).
--define(alert(Attrs, Fmt, Args), lager:alert(Attrs, Fmt, Args)).
-
--define(emergency(Fmt), lager:emergency(Fmt)).
--define(emergency(Fmt, Args), lager:emergency(Fmt, Args)).
--define(emergency(Attrs, Fmt, Args), lager:emergency(Attrs, Fmt, Args)).
+-define(error(Fmt), error_logger:error_msg(Fmt ++ "\n")).
+-define(error(Fmt, Args), error_logger:error_msg(Fmt ++ "\n", Args)).
 
 -endif.