Implement render_template & render_partial subscriptions

.rspec

@@ -1,2 +1,3 @@
 --format progress
 --color
+--order rand

README.md

@@ -55,6 +55,9 @@ InfluxDB::Rails.configure do |config|
   # config.series_name_for_controller_runtimes = "rails.controller"
   # config.series_name_for_view_runtimes       = "rails.view"
   # config.series_name_for_db_runtimes         = "rails.db"
+  # config.series_name_for_render_template     = "rails.render_template"
+  # config.series_name_for_render_partial      = "rails.render_partial"
+  # config.series_name_for_render_collection   = "rails.render_collection"
   # config.series_name_for_exceptions          = "rails.exceptions"
   # config.series_name_for_instrumentation     = "instrumentation"
 
@@ -68,8 +71,17 @@ To see all default values, take a look into `InfluxDB::Rails::Configuration::DEF
 defined in `lib/influxdb/rails/configuration.rb`
 
 Out of the box, you'll automatically get reporting of your controller,
-view, and db runtimes for each request. You can also call through to the
-underlying `InfluxDB::Client` object to write arbitrary data like this:
+view, and db runtimes and rendering of template, partial and collection for each request.
+
+It is possible to disable the rendering series by setting the series_name to nil.
+
+```ruby
+  # config.series_name_for_render_template     = nil
+  # config.series_name_for_render_partial      = nil
+  # config.series_name_for_render_collection   = nil
+```
+
+You can also call through to the underlying `InfluxDB::Client` object to write arbitrary data like this:
 
 ``` ruby
 InfluxDB::Rails.client.write_point "events",

lib/influxdb-rails.rb

@@ -2,6 +2,8 @@
 require "net/https"
 require "rubygems"
 require "socket"
+require "influxdb/rails/middleware/render_subscriber"
+require "influxdb/rails/middleware/request_subscriber"
 require "influxdb/rails/version"
 require "influxdb/rails/logger"
 require "influxdb/rails/exception_presenter"
@@ -84,55 +86,11 @@ def report_exception(ex, env = {})
       end
       alias transmit report_exception
 
-      def handle_action_controller_metrics(_name, start, finish, _id, payload)
-        tags = configuration.tags_middleware.call({
-          status:      payload[:status],
-          format:      payload[:format],
-          http_method: payload[:method],
-          method:      "#{payload[:controller]}##{payload[:action]}",
-          server:      Socket.gethostname,
-          app_name:    configuration.application_name,
-        }.reject { |_, value| value.nil? })
-
-        ts = convert_timestamp(finish.utc)
-
-        begin
-          {
-            configuration.series_name_for_controller_runtimes => ((finish - start) * 1000).ceil,
-            configuration.series_name_for_view_runtimes       => (payload[:view_runtime] || 0).ceil,
-            configuration.series_name_for_db_runtimes         => (payload[:db_runtime] || 0).ceil,
-          }.each do |series_name, value|
-            client.write_point series_name, values: { value: value }, tags: tags, timestamp: ts
-          end
-        rescue StandardError => e
-          log :error, "[InfluxDB::Rails] Unable to write points: #{e.message}"
-        end
-      end
-
       # rubocop:enable Metrics/MethodLength
       # rubocop:enable Metrics/AbcSize
 
-      TIMESTAMP_CONVERSIONS = {
-        "ns" => 1e9.to_r,
-        nil  => 1e9.to_r,
-        "u"  => 1e6.to_r,
-        "ms" => 1e3.to_r,
-        "s"  => 1.to_r,
-        "m"  => 1.to_r / 60,
-        "h"  => 1.to_r / 60 / 60,
-      }.freeze
-      private_constant :TIMESTAMP_CONVERSIONS
-
-      def convert_timestamp(time)
-        conv = TIMESTAMP_CONVERSIONS.fetch(configuration.time_precision) do
-          raise "Invalid time precision: #{configuration.time_precision}"
-        end
-
-        (time.to_r * conv).to_i
-      end
-
       def current_timestamp
-        convert_timestamp(Time.now.utc)
+        InfluxDB.convert_timestamp(Time.now.utc, configuration.time_precision)
       end
 
       def ignorable_exception?(ex)

lib/influxdb/rails/configuration.rb

@@ -21,6 +21,9 @@ class Configuration # rubocop:disable Style/Documentation
       attr_accessor :series_name_for_db_runtimes
       attr_accessor :series_name_for_exceptions
       attr_accessor :series_name_for_instrumentation
+      attr_accessor :series_name_for_render_template
+      attr_accessor :series_name_for_render_partial
+      attr_accessor :series_name_for_render_collection
 
       attr_accessor :tags_middleware
       attr_accessor :rails_app_name
@@ -66,6 +69,9 @@ class Configuration # rubocop:disable Style/Documentation
         series_name_for_db_runtimes:         "rails.db".freeze,
         series_name_for_exceptions:          "rails.exceptions".freeze,
         series_name_for_instrumentation:     "instrumentation".freeze,
+        series_name_for_render_template:     "rails.render_template".freeze,
+        series_name_for_render_partial:      "rails.render_partial".freeze,
+        series_name_for_render_collection:   "rails.render_collection".freeze,
 
         tags_middleware:                     ->(tags) { tags },
         rails_app_name:                      nil,
@@ -126,6 +132,9 @@ def initialize
         @series_name_for_db_runtimes          = DEFAULTS[:series_name_for_db_runtimes]
         @series_name_for_exceptions           = DEFAULTS[:series_name_for_exceptions]
         @series_name_for_instrumentation      = DEFAULTS[:series_name_for_instrumentation]
+        @series_name_for_render_template      = DEFAULTS[:series_name_for_render_template]
+        @series_name_for_render_partial       = DEFAULTS[:series_name_for_render_partial]
+        @series_name_for_render_collection    = DEFAULTS[:series_name_for_render_collection]
 
         @tags_middleware = DEFAULTS[:tags_middleware]
         @rails_app_name = DEFAULTS[:rails_app_name]

lib/influxdb/rails/middleware/render_subscriber.rb

@@ -0,0 +1,50 @@
+require "influxdb/rails/middleware/subscriber"
+
+module InfluxDB
+  module Rails
+    module Middleware
+      class RenderSubscriber < Subscriber
+        attr_reader :series_name
+
+        def initialize(configuration, series_name)
+          @series_name = series_name
+          super(configuration)
+        end
+
+        def call(_name, started, finished, _unique_id, payload)
+          return unless enabled?
+
+          value = ((finished - started) * 1000).ceil
+          ts = InfluxDB.convert_timestamp(finished.utc, configuration.time_precision)
+          begin
+            InfluxDB::Rails.client.write_point series_name, values: { value: value }, tags: tags(payload), timestamp: ts
+          rescue StandardError => e
+            log :error, "[InfluxDB::Rails] Unable to write points: #{e.message}"
+          end
+        end
+
+        private
+
+        def enabled?
+          super && series_name.present?
+        end
+
+        def location
+          [
+            Thread.current[:_influxdb_rails_controller],
+            Thread.current[:_influxdb_rails_action],
+          ].reject(&:blank?).join("#")
+        end
+
+        def tags(payload)
+          {
+            location:   location,
+            filename:   payload[:identifier],
+            count:      payload[:count],
+            cache_hits: payload[:cache_hits],
+          }.reject { |_, value| value.blank? }
+        end
+      end
+    end
+  end
+end

lib/influxdb/rails/middleware/request_subscriber.rb

@@ -0,0 +1,47 @@
+require "influxdb/rails/middleware/subscriber"
+
+module InfluxDB
+  module Rails
+    module Middleware
+      class RequestSubscriber < Subscriber
+        def call(_name, start, finish, _id, payload)
+          return unless enabled?
+
+          ts = InfluxDB.convert_timestamp(finish.utc, configuration.time_precision)
+          begin
+            series(payload, start, finish).each do |series_name, value|
+              InfluxDB::Rails.client.write_point series_name, values: { value: value }, tags: tags(payload), timestamp: ts
+            end
+          rescue StandardError => e
+            log :error, "[InfluxDB::Rails] Unable to write points: #{e.message}"
+          ensure
+            Thread.current[:_influxdb_rails_controller] = nil
+            Thread.current[:_influxdb_rails_action]     = nil
+          end
+        end
+
+        private
+
+        def series(payload, start, finish)
+          {
+            configuration.series_name_for_controller_runtimes => ((finish - start) * 1000).ceil,
+            configuration.series_name_for_view_runtimes       => (payload[:view_runtime] || 0).ceil,
+            configuration.series_name_for_db_runtimes         => (payload[:db_runtime] || 0).ceil,
+          }
+        end
+
+        def tags(payload)
+          configuration.tags_middleware.call(
+            {
+              method:      "#{payload[:controller]}##{payload[:action]}",
+              status:      payload[:status],
+              format:      payload[:format],
+              http_method: payload[:method],
+              server:      Socket.gethostname,
+              app_name:    configuration.application_name,
+            }.reject { |_, value| value.nil? })
+        end
+      end
+    end
+  end
+end

lib/influxdb/rails/middleware/subscriber.rb

@@ -0,0 +1,24 @@
+require "influxdb/rails/logger"
+
+module InfluxDB
+  module Rails
+    module Middleware
+      class Subscriber
+        include InfluxDB::Rails::Logger
+
+        attr_reader :configuration
+
+        def initialize(configuration)
+          @configuration = configuration
+        end
+
+        private
+
+        def enabled?
+          configuration.instrumentation_enabled? &&
+            !configuration.ignore_current_environment?
+        end
+      end
+    end
+  end
+end

lib/influxdb/rails/railtie.rb

@@ -22,19 +22,23 @@ class Railtie < ::Rails::Railtie # :nodoc:
         ::ActionDispatch::DebugExceptions.prepend InfluxDB::Rails::Middleware::HijackRenderException
 
         if defined?(ActiveSupport::Notifications)
-          listen = lambda do |name, start, finish, id, payload|
-            c = InfluxDB::Rails.configuration
-
-            if c.instrumentation_enabled? && !c.ignore_current_environment?
-              begin
-                InfluxDB::Rails.handle_action_controller_metrics(name, start, finish, id, payload)
-              rescue StandardError => e
-                c.logger.error "[InfluxDB::Rails] Failed writing points to InfluxDB: #{e.message}"
-              end
-            end
+          ActiveSupport::Notifications.subscribe "start_processing.action_controller" do |name, start, finish, id, payload|
+            Thread.current[:_influxdb_rails_controller] = payload[:controller]
+            Thread.current[:_influxdb_rails_action]     = payload[:action]
           end
 
-          ActiveSupport::Notifications.subscribe "process_action.action_controller", &listen
+          config = InfluxDB::Rails.configuration
+          request_subsriber = Middleware::RequestSubscriber.new(config)
+          ActiveSupport::Notifications.subscribe "process_action.action_controller", request_subsriber
+
+          render_template_subscriber = Middleware::RenderSubscriber.new(config, config.series_name_for_render_template)
+          ActiveSupport::Notifications.subscribe "render_template.action_view", render_template_subscriber
+
+          render_partial_subscriber = Middleware::RenderSubscriber.new(config, config.series_name_for_render_partial)
+          ActiveSupport::Notifications.subscribe "render_partial.action_view", render_partial_subscriber
+
+          render_collection_subscriber = Middleware::RenderSubscriber.new(config, config.series_name_for_render_collection)
+          ActiveSupport::Notifications.subscribe "render_collection.action_view", render_collection_subscriber
         end
       end
     end

spec/integration/metrics_spec.rb

@@ -1,21 +1,16 @@
 require File.expand_path(File.dirname(__FILE__) + "/integration_helper")
 
-RSpec.describe "collecting metrics through ActiveSupport::Notifications", type: :request do
+RSpec.describe WidgetsController, type: :controller do
+  render_views
+
   before do
-    InfluxDB::Rails.configure do |config|
-      config.ignored_environments = %w[development]
-    end
+    allow_any_instance_of(InfluxDB::Rails::Configuration).to receive(:ignored_environments).and_return(%w[development])
   end
 
   describe "in a normal request" do
-    it "should attempt to handle ActionController metrics" do
-      expect(InfluxDB::Rails).to receive(:handle_action_controller_metrics).once
-      get "/widgets"
-    end
-
     it "should result in attempts to write metrics via the client" do
-      expect(InfluxDB::Rails.client).to receive(:write_point).exactly(3).times
-      get "/widgets"
+      expect(InfluxDB::Rails.client).to receive(:write_point).exactly(6).times
+      get :index
     end
   end
 end

spec/support/rails4/app.rb

@@ -5,7 +5,7 @@
 app.config.session_store :cookie_store, key: "_myapp_session"
 app.config.active_support.deprecation = :log
 app.config.eager_load = false
-app.config.root = File.dirname(__FILE__)
+app.config.root = __dir__
 Rails.backtrace_cleaner.remove_silencers!
 app.initialize!
 
@@ -18,9 +18,9 @@
 
 class ApplicationController < ActionController::Base; end
 class WidgetsController < ApplicationController
-  def index
-    render nothing: true
-  end
+  prepend_view_path File.join(__dir__, "..", "views")
+
+  def index; end
 
   def new
     1 / 0

spec/support/rails5/app.rb

@@ -6,7 +6,7 @@
 app.config.session_store :cookie_store, key: "_myapp_session"
 app.config.active_support.deprecation = :log
 app.config.eager_load = false
-app.config.root = File.dirname(__FILE__)
+app.config.root = __dir__
 Rails.backtrace_cleaner.remove_silencers!
 app.initialize!
 
@@ -19,9 +19,9 @@
 
 class ApplicationController < ActionController::Base; end
 class WidgetsController < ApplicationController
-  def index
-    head 200
-  end
+  prepend_view_path File.join(__dir__, "..", "views")
+
+  def index; end
 
   def new
     1 / 0

spec/support/views/widgets/_item.html.erb

@@ -0,0 +1 @@
+<div>item</div

spec/support/views/widgets/index.html.erb

@@ -0,0 +1,5 @@
+<h1>Index page</h1>
+<div>
+  <%= render partial: 'item' %>
+  <%= render partial: 'item', collection: [1,2,3] %>
+</div>