Code for step 6

Author: akoutmos

config/config.exs

@@ -15,7 +15,27 @@ config :elixir_monitoring_prom, ElixirMonitoringPromWeb.Endpoint,
   url: [host: "localhost"],
   secret_key_base: "nFSyXdlKCXuXTXWhnmEeVnA9VLzzbpuqX3UvpdaPo8uqpgjxd+cZorH+0GobASx8",
   render_errors: [view: ElixirMonitoringPromWeb.ErrorView, accepts: ~w(html json)],
-  pubsub: [name: ElixirMonitoringProm.PubSub, adapter: Phoenix.PubSub.PG2]
+  pubsub: [name: ElixirMonitoringProm.PubSub, adapter: Phoenix.PubSub.PG2],
+  instrumenters: [ElixirMonitoringProm.PhoenixInstrumenter]
+
+config :prometheus, ElixirMonitoringProm.PipelineInstrumenter,
+  labels: [:status_class, :method, :host, :scheme, :request_path],
+  duration_buckets: [
+    10,
+    100,
+    1_000,
+    10_000,
+    100_000,
+    300_000,
+    500_000,
+    750_000,
+    1_000_000,
+    1_500_000,
+    2_000_000,
+    3_000_000
+  ],
+  registry: :default,
+  duration_unit: :microseconds
 
 # Configures Elixir's Logger
 config :logger, :console,

lib/elixir_monitoring_prom/application.ex

@@ -6,6 +6,23 @@ defmodule ElixirMonitoringProm.Application do
   use Application
 
   def start(_type, _args) do
+    # Start all the instrumenters
+    ElixirMonitoringProm.PhoenixInstrumenter.setup()
+    ElixirMonitoringProm.PipelineInstrumenter.setup()
+    ElixirMonitoringProm.RepoInstrumenter.setup()
+    ElixirMonitoringProm.PrometheusExporter.setup()
+
+    # NOTE: Only for FreeBSD, Linux and OSX (experimental)
+    # https://github.com/deadtrickster/prometheus_process_collector
+    Prometheus.Registry.register_collector(:prometheus_process_collector)
+
+    :telemetry.attach(
+      "prometheus-ecto",
+      [:elixir_monitoring_prom, :repo, :query],
+      &ElixirMonitoringProm.RepoInstrumenter.handle_event/4,
+      nil
+    )
+
     # List all child processes to be supervised
     children = [
       # Start the Ecto repository

lib/elixir_monitoring_prom_web/endpoint.ex

@@ -42,5 +42,9 @@ defmodule ElixirMonitoringPromWeb.Endpoint do
     key: "_elixir_monitoring_prom_key",
     signing_salt: "iPbxnMI/"
 
+  # Creates the /metrics endpoint for prometheus & collect stats
+  plug ElixirMonitoringProm.PrometheusExporter
+  plug ElixirMonitoringProm.PipelineInstrumenter
+
   plug ElixirMonitoringPromWeb.Router
 end

lib/instrumenters.ex

@@ -0,0 +1,35 @@
+defmodule ElixirMonitoringProm.PhoenixInstrumenter do
+  @moduledoc "Prometheus instrmenter for Phoenix"
+
+  use Prometheus.PhoenixInstrumenter
+end
+
+defmodule ElixirMonitoringProm.PipelineInstrumenter do
+  @moduledoc "Prometheus instrmenter for Phoenix"
+
+  use Prometheus.PlugPipelineInstrumenter
+
+  def label_value(:request_path, conn) do
+    case Phoenix.Router.route_info(
+           ElixirMonitoringPromWeb.Router,
+           conn.method,
+           conn.request_path,
+           ""
+         ) do
+      %{route: path} -> path
+      _ -> "unkown"
+    end
+  end
+end
+
+defmodule ElixirMonitoringProm.RepoInstrumenter do
+  @moduledoc "Prometheus instrmenter for Phoenix"
+
+  use Prometheus.EctoInstrumenter
+end
+
+defmodule ElixirMonitoringProm.PrometheusExporter do
+  @moduledoc "Prometheus instrmenter for Phoenix"
+
+  use Prometheus.PlugExporter
+end

mix.exs

@@ -45,7 +45,13 @@ defmodule ElixirMonitoringProm.MixProject do
       {:plug_cowboy, "~> 2.0"},
       {:geo, "~> 3.1.0"},
       {:geo_postgis, "~> 3.1.0"},
-      {:faker, "~> 0.12.0"}
+      {:faker, "~> 0.12.0"},
+      {:prometheus, "~> 4.4.1"},
+      {:prometheus_ex, "~> 3.0.5"},
+      {:prometheus_ecto, "~> 1.4.3"},
+      {:prometheus_phoenix, "~> 1.3.0"},
+      {:prometheus_plugs, "~> 1.1.5"},
+      {:prometheus_process_collector, "~> 1.4.3"}
     ]
   end
 

mix.lock

@@ -1,4 +1,5 @@
 %{
+  "accept": {:hex, :accept, "0.3.5", "b33b127abca7cc948bbe6caa4c263369abf1347cfa9d8e699c6d214660f10cd1", [:rebar3], [], "hexpm"},
   "connection": {:hex, :connection, "1.0.4", "a1cae72211f0eef17705aaededacac3eb30e6625b04a6117c1b2db6ace7d5976", [:mix], [], "hexpm"},
   "cowboy": {:hex, :cowboy, "2.6.3", "99aa50e94e685557cad82e704457336a453d4abcb77839ad22dbe71f311fcc06", [:rebar3], [{:cowlib, "~> 2.7.3", [hex: :cowlib, repo: "hexpm", optional: false]}, {:ranch, "~> 1.7.1", [hex: :ranch, repo: "hexpm", optional: false]}], "hexpm"},
   "cowlib": {:hex, :cowlib, "2.7.3", "a7ffcd0917e6d50b4d5fb28e9e2085a0ceb3c97dea310505f7460ff5ed764ce9", [:rebar3], [], "hexpm"},
@@ -22,6 +23,12 @@
   "plug_cowboy": {:hex, :plug_cowboy, "2.1.0", "b75768153c3a8a9e8039d4b25bb9b14efbc58e9c4a6e6a270abff1cd30cbe320", [:mix], [{:cowboy, "~> 2.5", [hex: :cowboy, repo: "hexpm", optional: false]}, {:plug, "~> 1.7", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
   "plug_crypto": {:hex, :plug_crypto, "1.0.0", "18e49317d3fa343f24620ed22795ec29d4a5e602d52d1513ccea0b07d8ea7d4d", [:mix], [], "hexpm"},
   "postgrex": {:hex, :postgrex, "0.15.0", "dd5349161019caeea93efa42f9b22f9d79995c3a86bdffb796427b4c9863b0f0", [:mix], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 2.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.5", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm"},
+  "prometheus": {:hex, :prometheus, "4.4.1", "1e96073b3ed7788053768fea779cbc896ddc3bdd9ba60687f2ad50b252ac87d6", [:mix, :rebar3], [], "hexpm"},
+  "prometheus_ecto": {:hex, :prometheus_ecto, "1.4.3", "3dd4da1812b8e0dbee81ea58bb3b62ed7588f2eae0c9e97e434c46807ff82311", [:mix], [{:ecto, "~> 2.0 or ~> 3.0", [hex: :ecto, repo: "hexpm", optional: false]}, {:prometheus_ex, "~> 1.1 or ~> 2.0 or ~> 3.0", [hex: :prometheus_ex, repo: "hexpm", optional: false]}], "hexpm"},
+  "prometheus_ex": {:hex, :prometheus_ex, "3.0.5", "fa58cfd983487fc5ead331e9a3e0aa622c67232b3ec71710ced122c4c453a02f", [:mix], [{:prometheus, "~> 4.0", [hex: :prometheus, repo: "hexpm", optional: false]}], "hexpm"},
+  "prometheus_phoenix": {:hex, :prometheus_phoenix, "1.3.0", "c4b527e0b3a9ef1af26bdcfbfad3998f37795b9185d475ca610fe4388fdd3bb5", [:mix], [{:phoenix, "~> 1.4", [hex: :phoenix, repo: "hexpm", optional: false]}, {:prometheus_ex, "~> 1.3 or ~> 2.0 or ~> 3.0", [hex: :prometheus_ex, repo: "hexpm", optional: false]}], "hexpm"},
+  "prometheus_plugs": {:hex, :prometheus_plugs, "1.1.5", "25933d48f8af3a5941dd7b621c889749894d8a1082a6ff7c67cc99dec26377c5", [:mix], [{:accept, "~> 0.1", [hex: :accept, repo: "hexpm", optional: false]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: false]}, {:prometheus_ex, "~> 1.1 or ~> 2.0 or ~> 3.0", [hex: :prometheus_ex, repo: "hexpm", optional: false]}, {:prometheus_process_collector, "~> 1.1", [hex: :prometheus_process_collector, repo: "hexpm", optional: true]}], "hexpm"},
+  "prometheus_process_collector": {:hex, :prometheus_process_collector, "1.4.3", "657386e8f142fc817347d95c1f3a05ab08710f7df9e7f86db6facaed107ed929", [:rebar3], [{:prometheus, "~> 4.0", [hex: :prometheus, repo: "hexpm", optional: false]}], "hexpm"},
   "ranch": {:hex, :ranch, "1.7.1", "6b1fab51b49196860b733a49c07604465a47bdb78aa10c1c16a3d199f7f8c881", [:rebar3], [], "hexpm"},
   "telemetry": {:hex, :telemetry, "0.4.0", "8339bee3fa8b91cb84d14c2935f8ecf399ccd87301ad6da6b71c09553834b2ab", [:rebar3], [], "hexpm"},
 }