Add Metrics example

examples/roll_dice/README.md

@@ -17,6 +17,19 @@ To generate and view traces:
 
 For more information on the OpenTelemetry instrumentation in this example, check out the guide for getting started with [OpenTelemetry](https://opentelemetry.io/docs/instrumentation/erlang/getting-started/)
 
+## No OpenTelemetry Metrics exported
+
+How to reproduce:
+
+Use Elixir 1.14.3 (compiled with Erlang/OTP 25)
+
+1. Start OTEL Collector `docker-compose up`
+2. `mix deps.get`
+3. `mix phx.server`
+4. `curl -X GET http://localhost:4000/api/rolldice`
+
+Notice that no metrics reach the OTEL Collector
+
 ## How did we get here?
 
 To begin, use the `phx` generator to create a new project. To keep things simple we'll leave out the database and html for now with the `--no-ecto` and `--no-html` flags.

examples/roll_dice/config/config.exs

@@ -25,6 +25,16 @@ config :logger, :console,
 # Use Jason for JSON parsing in Phoenix
 config :phoenix, :json_library, Jason
 
+config :opentelemetry,
+       resource: %{service: %{name: "roll_dice_app"}},
+       span_processor: :batch,
+       traces_exporter: :otlp,
+       metrics_exporter: :otlp
+
+config :opentelemetry_exporter,
+       otlp_protocol: :grpc,
+       otlp_endpoint: "http://localhost:4317"
+
 # Import environment specific config. This must remain at the bottom
 # of this file so it overrides the configuration defined above.
 import_config "#{config_env()}.exs"

examples/roll_dice/docker-compose.yml

@@ -1,7 +1,7 @@
 version: "3"
 services:
   otel:
-    image: otel/opentelemetry-collector-contrib:0.76.1
+    image: otel/opentelemetry-collector-contrib:0.86.0
     command: ["--config=/conf/otel-collector-config.yaml"]
     privileged: true
     ports:
@@ -10,14 +10,3 @@ services:
       - 55679:55679
     volumes:
       - ./otel-collector-config.yaml:/conf/otel-collector-config.yaml
-    links:
-      - jaeger-all-in-one
-
-  jaeger-all-in-one:
-    image: jaegertracing/all-in-one:1.45
-    restart: always
-    environment:
-      COLLECTOR_OTLP_ENABLED: true
-    ports:
-      - "16686:16686"
-      - "4317"

examples/roll_dice/lib/roll_dice/application.ex

@@ -4,12 +4,15 @@ defmodule RollDice.Application do
   @moduledoc false
 
   use Application
+  require OpenTelemetryAPIExperimental.Counter, as: Counter
 
   @impl true
   def start(_type, _args) do
     :opentelemetry_cowboy.setup()
     OpentelemetryPhoenix.setup(adapter: :cowboy2)
 
+    Counter.create(:number_of_messages, %{unit: "1", description: "some counter lusooo"})
+
     children = [
       # Start the Telemetry supervisor
       RollDiceWeb.Telemetry,

examples/roll_dice/lib/roll_dice_web/controllers/dice_controller.ex

@@ -1,12 +1,15 @@
 defmodule RollDiceWeb.DiceController do
   use RollDiceWeb, :controller
   require OpenTelemetry.Tracer, as: Tracer
+  require OpenTelemetryAPIExperimental.Counter, as: Counter
 
   def roll(conn, _params) do
     send_resp(conn, 200, roll_dice())
   end
 
   defp roll_dice do
+    Counter.add(:number_of_requests, 1)
+
     Tracer.with_span "roll_dice" do
       roll = Enum.random(1..6)
 

examples/roll_dice/mix.exs

@@ -43,11 +43,13 @@ defmodule RollDice.MixProject do
       {:gettext, "~> 0.20"},
       {:jason, "~> 1.2"},
       {:plug_cowboy, "~> 2.5"},
-      {:opentelemetry_exporter, "~> 1.5"},
-      {:opentelemetry, "~> 1.3"},
-      {:opentelemetry_api, "~> 1.2"},
-      {:opentelemetry_phoenix, "~> 1.1"},
-      {:opentelemetry_cowboy, "~> 0.2"},
+      {:opentelemetry_exporter, "~> 1.8"},
+      {:opentelemetry, "~> 1.5"},
+      {:opentelemetry_api, "~> 1.4"},
+      {:opentelemetry_api_experimental, "~> 0.5.1"},
+      {:opentelemetry_experimental, "~> 0.5.1"},
+      {:opentelemetry_phoenix, "~> 1.2"},
+      {:opentelemetry_cowboy, "~> 0.3"}
     ]
   end
 

examples/roll_dice/otel-collector-config.yaml

@@ -1,47 +1,29 @@
-# OpenTelemetry Collector config that receives OTLP and exports to Zipkin
 receivers:
   otlp:
     protocols:
       grpc:
-        endpoint: "0.0.0.0:4317"
+        endpoint: 0.0.0.0:4317
       http:
-        cors:
-          allowed_origins:
-          - "http://localhost:4000"
-        endpoint: "0.0.0.0:4318"
+        endpoint: 0.0.0.0:4318
+
 processors:
   batch:
-    send_batch_size: 1024
-    timeout: 5s
-exporters:
-  otlp:
-    endpoint: jaeger-all-in-one:4317
-    tls:
-      insecure: true
 
+exporters:
   debug:
     verbosity: detailed
-    sampling_initial: 1
-    sampling_thereafter: 1
-
-extensions:
-  zpages: {}
 
 service:
-  telemetry:
-    logs:
-      level: "debug"
-  extensions: [zpages]
   pipelines:
-    traces:
+    logs:
       receivers: [otlp]
       processors: [batch]
-      exporters: [debug, otlp]
+      exporters: [debug]
     metrics:
       receivers: [otlp]
       processors: [batch]
       exporters: [debug]
-    logs:
+    traces:
       receivers: [otlp]
       processors: [batch]
       exporters: [debug]