From 3015cd8f579c6c9db3073c5426a0192bbf983166 Mon Sep 17 00:00:00 2001
From: Sascha Kattelmann <sascha.kattelmann@1und1.de>
Date: Fri, 23 Jun 2017 15:35:23 +0200
Subject: [PATCH] Allow floats

---
 README.md                          |  2 +-
 src/exometer_report_prometheus.erl | 20 +++++++-------------
 test/exometer_prometheus_test.erl  |  2 +-
 3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/README.md b/README.md
index 2472912..3ad0fec 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ some_other_counter 1
 
 # HELP some_gauge some exometer gauge
 # TYPE some_gauge gauge
-some_gauge 1
+some_gauge 1.1235
 
 # HELP some_spiral some exometer spiral
 # TYPE some_spiral gauge
diff --git a/src/exometer_report_prometheus.erl b/src/exometer_report_prometheus.erl
index f56ceca..a4728fb 100644
--- a/src/exometer_report_prometheus.erl
+++ b/src/exometer_report_prometheus.erl
@@ -101,22 +101,16 @@ format_metrics([{Metric, DataPoints, Name, Type, Help} | Metrics], Akk) ->
     format_metrics(Metrics, [Payload1, <<"\n">> | Akk]).
 
 make_metric_name(Metric) ->
-    lists:reverse(make_metric_name(Metric, [])).
-
-make_metric_name([], Akk) ->
-    Akk;
-make_metric_name([Elem], Akk) ->
-    [normalize(Elem) | Akk];
-make_metric_name([Elem | Metric], Akk) ->
-    make_metric_name(Metric, [<<"_">>, normalize(Elem) | Akk]).
-
-normalize(Something) ->
-    re:replace(ioize(Something), "-|\\.", "_", [global, {return,binary}]).
+    NameList = lists:join($_, lists:map(fun ioize/1, Metric)),
+    NameBin = iolist_to_binary(NameList),
+    re:replace(NameBin, "-|\\.", "_", [global, {return,binary}]).
 
 ioize(Atom) when is_atom(Atom) ->
     atom_to_binary(Atom, utf8);
-ioize(Number) when is_integer(Number) or is_float(Number) ->
-    list_to_binary(integer_to_list(trunc(Number)));
+ioize(Number) when is_float(Number) ->
+    float_to_binary(Number, [{decimals, 4}]);
+ioize(Number) when is_integer(Number) ->
+    integer_to_binary(Number);
 ioize(Something) ->
     Something.
 
diff --git a/test/exometer_prometheus_test.erl b/test/exometer_prometheus_test.erl
index 5642fd2..d94e450 100644
--- a/test/exometer_prometheus_test.erl
+++ b/test/exometer_prometheus_test.erl
@@ -21,7 +21,7 @@ basic_test() ->
     ok = exometer_report:subscribe(?REPORTER, [some, other, counter], [value, ms_since_reset], manual,
                                    [{type, counter}, {help, "some other exometer counter with forced type"}]),
 
-    ok = exometer:update_or_create([some, gauge], 1, gauge, []),
+    ok = exometer:update_or_create([some, gauge], 1.1234567, gauge, []),
     ok = exometer_report:subscribe(?REPORTER, [some, gauge], [value, ms_since_reset], manual, [{help, "some exometer gauge"}]),
 
     ok = exometer:update_or_create([some, spiral], 1, spiral, []),