can record spans as summary

Author: deadtrickster

mix.exs

@@ -8,7 +8,10 @@ defmodule OpencensusErlangPrometheus.Mixfile do
      deps: deps(),
      description: description(),
      package: package(),
-     erlc_options: [:warnings_as_errors],
+     erlc_options: [:warnings_as_errors,
+                    :warn_export_vars,
+                    :warn_shadow_vars,
+                    :warn_obsolete_guard],
      elixirc_options: [warnings_as_errors: true],
      test_coverage: [tool: ExCoveralls],
      preferred_cli_env: ["coveralls": :test, "coveralls.html": :test]]
@@ -23,12 +26,13 @@ defmodule OpencensusErlangPrometheus.Mixfile do
   defp package do
     [maintainers: ["Ilya Khaprov"],
      licenses: ["MIT"],
-     links: %{"GitHub" => "https://github.com/deadtrickster/opencensus_erlang_prometheus"},
+     links: %{"GitHub" => "https://github.com/deadtrickster/opencensus-erlang-prometheus"},
      files: ["priv", "src", "README.md", "rebar.config"]]
   end
 
   defp deps do
-    [{:prometheus, "~> 3.4"},
+    [{:prometheus, "~> 3.4", manager: :rebar3},
+     {:opencensus, git: "https://github.com/deadtrickster/opencensus-erlang", branch: "fix-mix-dep"},
      {:credo, "~> 0.8.7", only: [:dev, :test]},
      {:excoveralls, "~> 0.7.3", only: [:test]}]
   end

mix.lock

@@ -8,6 +8,10 @@
   "jsx": {:hex, :jsx, "2.8.2", "7acc7d785b5abe8a6e9adbde926a24e481f29956dd8b4df49e3e4e7bcc92a018", [], [], "hexpm"},
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [], [], "hexpm"},
   "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [], [], "hexpm"},
+  "opencensus": {:git, "https://github.com/deadtrickster/opencensus-erlang", "c31853dfb1656f0d057cf69b569a8792ef5bd6c5", [branch: "fix-mix-dep"]},
   "prometheus": {:hex, :prometheus, "3.4.1", "90c4f37670c4dc7de9319a0c310bf12cb619715ebe285f583f3b46d955ee8f81", [], [], "hexpm"},
+  "rebar_erl_vsn": {:hex, :rebar_erl_vsn, "0.1.3", "431667f3203f19130805a8ac7cde9666d1bff7235eb2b96e2048eb839db0ed1f", [], [], "hexpm"},
+  "rfc3339": {:hex, :rfc3339, "0.9.0", "2075653dc9407541c84b1e15f8bda2abe95fb17c9694025e079583f2d19c1060", [], [], "hexpm"},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.1", "28a4d65b7f59893bc2c7de786dec1e1555bd742d336043fe644ae956c3497fbe", [], [], "hexpm"},
-  "unicode_util_compat": {:hex, :unicode_util_compat, "0.3.1", "a1f612a7b512638634a603c8f401892afbf99b8ce93a45041f8aaca99cadb85e", [], [], "hexpm"}}
+  "unicode_util_compat": {:hex, :unicode_util_compat, "0.3.1", "a1f612a7b512638634a603c8f401892afbf99b8ce93a45041f8aaca99cadb85e", [], [], "hexpm"},
+  "wts": {:hex, :wts, "0.3.0", "5cdf22c775cb1ebae24c326a5db6074d753c42f4bd12a9aa47cc62d3e2c71ad1", [], [{:rfc3339, "~>0.9.0", [hex: :rfc3339, repo: "hexpm", optional: false]}], "hexpm"}}

rebar.config

@@ -3,8 +3,11 @@
 
 {post_hooks, []}.
 
-{deps, [{prometheus, "3.4.1"}]}.
-{shell, [{apps, [opencensus_erlang_prometheus]}]}.
+{deps, [{prometheus, "3.4.1"},
+        {opencensus,
+         {git, "https://github.com/census-instrumentation/opencensus-erlang",
+          {branch, "master"}}}]}.
+% {shell, [{apps, [opencensus_erlang_prometheus]}]}.
 {cover_enabled, true}.
 {cover_export_enabled, true}.
 {cover_excl_mods, [
@@ -14,8 +17,11 @@
 {coveralls_service_name , "travis-ci"}.
 
 {xref_extra_paths,[]}.
-{xref_checks,[undefined_function_calls,undefined_functions,locals_not_used,
-              deprecated_function_calls,deprecated_functions]}.
+{xref_checks,[undefined_function_calls,
+              undefined_functions,
+              locals_not_used,
+              deprecated_function_calls,
+              deprecated_functions]}.
 
 {profiles, [{docs, [{deps, [{edown, "0.8.1"}]},
                     {edoc_opts,
@@ -27,7 +33,8 @@
                        {"./README.md",
                         "https://github.com/deadtrickster/opencensus-erlang-prometheus"}}]}]},
             {test, [{plugins, [{coveralls, "1.4.0"},
-                               {rebar3_elvis_plugin, "0.0.4"}]}]},
+                               {rebar3_elvis_plugin, "0.0.4"}]},
+                    {erl_opts, [nowarn_export_all]}]},
             {benchmark, [{src_dirs, ["src", "benchmark"]},
                          {deps, [{'erlang-color',
                                   {git, "https://github.com/julianduque/erlang-color",

rebar.lock

@@ -1,6 +1,14 @@
 {"1.1.0",
-[{<<"prometheus">>,{pkg,<<"prometheus">>,<<"3.4.1">>},0}]}.
+[{<<"opencensus">>,
+  {git,"https://github.com/census-instrumentation/opencensus-erlang",
+       {ref,"b8fecf303896a9bdbfe9d1f83371a5bc1e88a28a"}},
+  0},
+ {<<"prometheus">>,{pkg,<<"prometheus">>,<<"3.4.1">>},0},
+ {<<"rfc3339">>,{pkg,<<"rfc3339">>,<<"0.9.0">>},2},
+ {<<"wts">>,{pkg,<<"wts">>,<<"0.3.0">>},1}]}.
 [
 {pkg_hash,[
- {<<"prometheus">>, <<"90C4F37670C4DC7DE9319A0C310BF12CB619715EBE285F583F3B46D955EE8F81">>}]}
+ {<<"prometheus">>, <<"90C4F37670C4DC7DE9319A0C310BF12CB619715EBE285F583F3B46D955EE8F81">>},
+ {<<"rfc3339">>, <<"2075653DC9407541C84B1E15F8BDA2ABE95FB17C9694025E079583F2D19C1060">>},
+ {<<"wts">>, <<"5CDF22C775CB1EBAE24C326A5DB6074D753C42F4BD12A9AA47CC62D3E2C71AD1">>}]}
 ].

src/oc_prometheus_reporter.erl

@@ -0,0 +1,31 @@
+-module(oc_prometheus_reporter).
+
+-include_lib("opencensus/include/opencensus.hrl").
+
+-behaviour(oc_reporter).
+
+-export([init/1,
+         report/2]).
+
+%% ===================================================================
+%% API
+%% ===================================================================
+
+init(_) ->
+  prometheus_summary:declare([{name, "span"},
+                              {labels, [name]},
+                              {help, "Opencensus span"}]),
+  ok.
+
+report(Spans, _Opts) ->
+  [
+   prometheus_summary:observe("span", [Span#span.name],
+                              wts:duration(Span#span.start_time, Span#span.end_time))
+
+   || Span <- Spans],
+  ok.
+
+
+%% ===================================================================
+%% Private functions
+%% ===================================================================

src/opencensus_erlang_prometheus.app.src

@@ -4,12 +4,14 @@
   {registered, []},
   {applications,
    [kernel,
-    stdlib
+    stdlib,
+    prometheus,
+    opencensus
    ]},
   {env,[]},
   {modules, []},
 
   {maintainers, ["Ilya Khaprov"]},
   {licenses, ["MIT"]},
-  {links, [{"Github", "https://github.com/deadtrickster/opencensus_erlang_prometheus"}]}
+  {links, [{"Github", "https://github.com/deadtrickster/opencensus-erlang-prometheus"}]}
  ]}.

test/ct/oep_SUITE.erl

@@ -0,0 +1,44 @@
+-module(oep_SUITE).
+
+-compile(export_all).
+
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("common_test/include/ct.hrl").
+
+-include_lib("opencensus/include/opencensus.hrl").
+
+all() ->
+  [prometheus_reporter].
+
+init_per_suite(Config) ->
+  Config.
+
+end_per_suite(_Config) ->
+  ok.
+
+%% ===================================================================
+%% Tests
+%% ===================================================================
+
+prometheus_reporter(_Config) -> 
+  application:set_env(opencensus, reporter, {oc_prometheus_reporter, []}),
+  ok = application:load(opencensus),
+  application:set_env(opencensus, reporter, {oc_prometheus_reporter, []}),
+  {ok, _} = application:ensure_all_started(opencensus_erlang_prometheus),
+
+  SpanName1 = <<"span-1">>,
+  Span1 = opencensus:start_span(SpanName1, opencensus:generate_trace_id(), undefined),
+
+  ChildSpanName1 = <<"child-span-1">>,
+  ChildSpan1 = opencensus:start_span(ChildSpanName1, Span1),
+  opencensus:finish_span(ChildSpan1),
+  opencensus:finish_span(Span1),
+
+  timer:sleep(1000),
+
+  ?assertMatch({1, _}, prometheus_summary:value("span", [SpanName1])),
+  ?assertMatch({1, _}, prometheus_summary:value("span", [ChildSpanName1])).
+
+%% ===================================================================
+%% Private functions
+%% ===================================================================