From dfdfd53a7e47abd94c67dc44523ba0117608e424 Mon Sep 17 00:00:00 2001
From: Tom de Bruijn <tom@tomdebruijn.com>
Date: Wed, 23 Oct 2024 09:16:21 +0200
Subject: [PATCH] Automatically ignore Rails' health-check

Adds the `Rails::HealthController#show` endpoint to the default
`ignore_actions` config by adding it to the Railtie loader defaults.

Suggested by a customer in:
https://app.intercom.com/a/inbox/yzor8gyw/inbox/shared/unassigned/conversation/16410700366724#part_id=comment-16410700366724-21909575460

Co-authored-by: Noemi <45180344+unflxw@users.noreply.github.com>
---
 .../ignore-rails-healthcheck-by-default.md    | 31 +++++++++++++++++++
 lib/appsignal/integrations/railtie.rb         |  3 +-
 .../appsignal/integrations/railtie_spec.rb    |  2 ++
 3 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 .changesets/ignore-rails-healthcheck-by-default.md

diff --git a/.changesets/ignore-rails-healthcheck-by-default.md b/.changesets/ignore-rails-healthcheck-by-default.md
new file mode 100644
index 000000000..5be9a005c
--- /dev/null
+++ b/.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
+```
diff --git a/lib/appsignal/integrations/railtie.rb b/lib/appsignal/integrations/railtie.rb
index 3ea6804a4..fb5706232 100644
--- a/lib/appsignal/integrations/railtie.rb
+++ b/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
 
diff --git a/spec/lib/appsignal/integrations/railtie_spec.rb b/spec/lib/appsignal/integrations/railtie_spec.rb
index db0c14a4c..cb05eccf9 100644
--- a/spec/lib/appsignal/integrations/railtie_spec.rb
+++ b/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