Merge pull request #1321 from appsignal/ignore-rails-healthcheck

Automatically ignore Rails' health-check

.changesets/ignore-rails-healthcheck-by-default.md

@@ -0,0 +1,31 @@
+---
+bump: patch
+type: change
+---
+
+Ignore the Rails healthcheck endpoint (Rails::HealthController#show) by default for Rails apps.
+
+If the `ignore_actions` option is set in the `config/appsignal.yml` file, the default is overwritten.
+If the `APPSIGNAL_IGNORE_ACTIONS` environment variable is set, the default is overwritten.
+When using the `Appsignal.configure` helper, add more actions to the default like so:
+
+```ruby
+# config/appsignal.rb
+Appsignal.configure do |config|
+  # Add more actions to ignore
+  config.ignore_actions << "My action"
+end
+```
+
+To overwrite the default using the `Appsignal.configure` helper, do either of the following:
+
+```ruby
+# config/appsignal.rb
+Appsignal.configure do |config|
+  # Overwrite the default value, ignoring all actions ignored by default
+  config.ignore_actions = ["My action"]
+
+  # To only remove the healtcheck endpoint
+  config.ignore_actions.delete("Rails::HealthController#show")
+end
+```

lib/appsignal/config.rb

@@ -243,15 +243,26 @@ def load_config
       @system_config = detect_from_system
       merge(system_config)
 
-      # Set defaults from loaders in reverse order so the first register
+      # Set defaults from loaders in reverse order so the first registered
       # loader's defaults overwrite all others
       self.class.loader_defaults.reverse.each do |loader_defaults|
+        options = config_hash
+        new_loader_defaults = {}
         defaults = loader_defaults[:options]
-        @loaders_config.merge!(defaults.merge(
+        defaults.each do |option, value|
+          new_loader_defaults[option] =
+            if ARRAY_OPTIONS.key?(option)
+              # Merge arrays: new value first
+              value + options[option]
+            else
+              value
+            end
+        end
+        @loaders_config.merge!(new_loader_defaults.merge(
           :root_path => loader_defaults[:root_path],
           :env => loader_defaults[:env]
         ))
-        merge(defaults)
+        merge(new_loader_defaults)
       end
 
       # Track origin of env

lib/appsignal/integrations/railtie.rb

@@ -45,7 +45,8 @@ def self.load_default_config
           :root_path => Rails.root,
           :env => Rails.env,
           :name => Appsignal::Utils::RailsHelper.detected_rails_app_name,
-          :log_path => Rails.root.join("log")
+          :log_path => Rails.root.join("log"),
+          :ignore_actions => ["Rails::HealthController#show"]
         )
       end
 

spec/lib/appsignal/cli/diagnose_spec.rb

@@ -926,7 +926,9 @@ def dont_accept_prompt_to_send_diagnostics_report
                 # Workaround to not being able to require the railtie file
                 # multiple times and triggering the Rails initialization process.
                 # This will be used whtn the MyApp app has already been loaded.
-                Appsignal::Integrations::Railtie.load_default_config if defined?(MyApp)
+                if defined?(MyApp) && MyApp::Application.initialized?
+                  Appsignal::Integrations::Railtie.load_default_config
+                end
                 run_within_dir(root_path)
               end
 
@@ -942,6 +944,7 @@ def dont_accept_prompt_to_send_diagnostics_report
                   "  ignore_actions: [\"Action from DSL\"]\n" \
                     "    Sources:\n" \
                     "      default: []\n" \
+                    "      loaders: [\"Rails::HealthController#show\"]\n" \
                     "      dsl:     [\"Action from DSL\"]\n"
                 )
 
@@ -951,7 +954,8 @@ def dont_accept_prompt_to_send_diagnostics_report
                     "root_path" => root_path,
                     "env" => "test",
                     "log_path" => File.join(rails_project_fixture_path, "log"),
-                    "name" => "MyApp"
+                    "name" => "MyApp",
+                    "ignore_actions" => ["Rails::HealthController#show"]
                   }
                 )
                 # Includes values from the DSL

spec/lib/appsignal/config_spec.rb

@@ -313,7 +313,7 @@ def on_load
           register_config_defaults(
             :env => "loader_env",
             :root_path => "loader-path",
-            :ignore_actions => ["loader-action"],
+            :ignore_actions => ["loader 1 action"],
             :my_option => "my_value",
             :nil_option => nil
           )
@@ -323,7 +323,7 @@ def on_load
     end
 
     it "overrides the default config option values" do
-      expect(config[:ignore_actions]).to eq(["loader-action"])
+      expect(config[:ignore_actions]).to eq(["loader 1 action"])
     end
 
     it "does not set any nil values" do
@@ -346,7 +346,8 @@ def on_load
           def on_load
             register_config_defaults(
               :my_option => "second_value",
-              :second_option => "second_value"
+              :second_option => "second_value",
+              :ignore_actions => ["loader 2 action"]
             )
           end
         end
@@ -358,6 +359,26 @@ def on_load
           :my_option => "my_value",
           :second_option => "second_value"
         )
+        expect(config.loaders_config).to include(
+          :my_option => "my_value",
+          :second_option => "second_value"
+        )
+      end
+
+      it "merges options with array values" do
+        expect(config.config_hash).to include(
+          :ignore_actions => ["loader 1 action", "loader 2 action"]
+        )
+        expect(config.loaders_config).to include(
+          :ignore_actions => ["loader 1 action", "loader 2 action"]
+        )
+
+        # Doesn't modify defaults
+        defaults = Appsignal::Config.loader_defaults
+        expect(defaults.find { |d| d[:name] == :options_loader }[:options][:ignore_actions])
+          .to eq(["loader 1 action"])
+        expect(defaults.find { |d| d[:name] == :options_loader2 }[:options][:ignore_actions])
+          .to eq(["loader 2 action"])
       end
     end
   end

spec/lib/appsignal/integrations/railtie_spec.rb

@@ -82,6 +82,8 @@ def initialize_railtie(event)
           expect(rails_defaults[:options][:name]).to eq("MyApp")
           expect(rails_defaults[:options][:log_path])
             .to eq(Pathname.new(File.join(rails_project_fixture_path, "log")))
+          expect(rails_defaults[:options][:ignore_actions])
+            .to eq(["Rails::HealthController#show"])
         end
 
         it "loads the app name from the project's appsignal.yml file" do