feat: Add Scout APM monitoring

Author: Betree

apps/cf/config/config.exs

@@ -57,5 +57,7 @@ config :guardian, Guardian.DB, repo: DB.Repo
 config :rollbax,
   enabled: :log
 
+config :scout_apm, name: "CaptainFact"
+
 # Import environment specific config
 import_config "#{Mix.env()}.exs"

apps/cf/mix.exs

@@ -58,6 +58,7 @@ defmodule CF.Mixfile do
       {:sweet_xml, "~> 0.6"},
       {:burnex, "~> 1.0"},
       {:yaml_elixir, "~> 2.4.0"},
+      {:scout_apm, "~> 1.0.6"},
 
       # ---- Internal ----
       {:db, in_umbrella: true},

apps/cf_graphql/lib/endpoint.ex

@@ -18,6 +18,7 @@ defmodule CF.GraphQLWeb.Endpoint do
     json_decoder: Poison
   )
 
+  plug(ScoutApm.Absinthe.Plug)
   plug(Plug.MethodOverride)
   plug(Plug.Head)
   plug(CF.GraphQLWeb.Router)

apps/cf_graphql/lib/scout_apm_absinthe_plug.ex

@@ -0,0 +1,32 @@
+defmodule ScoutApm.Absinthe.Plug do
+  alias ScoutApm.Internal.Layer
+
+  def init(default), do: default
+
+  def call(conn, _default) do
+    ScoutApm.TrackedRequest.start_layer("Controller", action_name(conn))
+
+    conn
+    |> Plug.Conn.register_before_send(&before_send/1)
+  end
+
+  def before_send(conn) do
+    full_name = action_name(conn)
+    uri = "#{conn.request_path}"
+
+    ScoutApm.TrackedRequest.stop_layer(fn layer ->
+      layer
+      |> Layer.update_name(full_name)
+      |> Layer.update_uri(uri)
+    end)
+
+    conn
+  end
+
+  # Takes a connection, extracts the phoenix controller & action, then manipulates & cleans it up.
+  # Returns a string like "PageController#index"
+  defp action_name(conn) do
+    action_name = conn.params["operationName"]
+    "GraphQL##{action_name}"
+  end
+end

apps/cf_graphql/mix.exs

@@ -41,6 +41,7 @@ defmodule CF.Graphql.Mixfile do
       {:absinthe_plug, "~> 1.4.1"},
       {:kaur, "~> 1.1"},
       {:poison, "~> 3.1"},
+      {:scout_apm, "~> 1.0.6"},
 
       # Internal dependencies
       {:db, in_umbrella: true},

apps/cf_jobs/lib/job.ex

@@ -6,6 +6,7 @@ defmodule CF.Jobs.Job do
   @type t :: module
 
   use GenServer
+  import ScoutApm.Tracing
 
   def init(args) do
     {:ok, args}

apps/cf_jobs/lib/jobs/create_notifications.ex

@@ -65,7 +65,7 @@ defmodule CF.Jobs.CreateNotifications do
   end
 
   # --- Server callbacks ---
-
+  @transaction_opts [type: "background", name: "update_notifications"]
   def handle_call({:update, force}, _from, _state) do
     last_action_id = ReportManager.get_last_action_id(@analyser_id)
 

apps/cf_jobs/lib/jobs/flags.ex

@@ -41,7 +41,7 @@ defmodule CF.Jobs.Flags do
   end
 
   # --- Server callbacks ---
-
+  @transaction_opts [type: "background", name: "update_flags"]
   def handle_call(:update_flags, _from, _state) do
     last_action_id = ReportManager.get_last_action_id(@analyser_id)
 

apps/cf_jobs/lib/jobs/moderation.ex

@@ -78,6 +78,7 @@ defmodule CF.Jobs.Moderation do
 
   # --- Internal API ---
 
+  @transaction_opts [type: "background", name: "update_moderation"]
   def handle_call(:update, _, _) do
     UserAction
     |> join(:inner, [a], uf in ModerationUserFeedback, uf.action_id == a.id)

apps/cf_jobs/lib/jobs/reputation.ex

@@ -99,7 +99,7 @@ defmodule CF.Jobs.Reputation do
     do: max(change, @daily_loss_limit - today_change)
 
   # --- Server callbacks ---
-
+  @transaction_opts [type: "background", name: "update_reputation"]
   def handle_call(:update_reputations, _from, _state) do
     last_action_id = ReportManager.get_last_action_id(@analyser_id)
 
@@ -114,6 +114,7 @@ defmodule CF.Jobs.Reputation do
     {:reply, :ok, :ok}
   end
 
+  @transaction_opts [type: "background", name: "reset_reputation_limits"]
   def handle_call(:reset_daily_limits, _from, _state) do
     Logger.info("[Jobs.Reputation] Reset daily limits")