Have daemon cleanup PID file at exit

lib/scout_apm/logging/monitor/monitor.rb

@@ -8,11 +8,21 @@ module ScoutApm
   module Logging
     class Monitor
       def run
+        add_exit_handler
+
         loop do
           sleep 1
           puts "Running..."
         end
       end
+
+      private
+
+      def add_exit_handler
+        at_exit do
+          File.delete(ScoutApm::Logging::MonitorManager::PID_FILE)
+        end
+      end
     end
   end
 end

lib/scout_apm/logging/monitor_manager.rb

@@ -12,6 +12,8 @@ def self.setup!
       def self.create_daemon
         return if File.exist? PID_FILE
 
+        # TODO: Investigate behavior of orphaned processes and copy on write behavior.
+        # Do we get all of the parent's memory? We may want to spawn the daemon.
         child_process = Process.fork do
           ScoutApm::Logging::Monitor.new.run
         end

spec/scout_apm_logging_spec.rb

@@ -10,7 +10,7 @@
     make_basic_app
   end
 
-  it "spawns the daemon process" do
+  it "checks lifecycle of the daemon process" do
     # Check if the PID file exists
     expect(File.exist?(ScoutApm::Logging::MonitorManager::PID_FILE)).to be_truthy
 
@@ -19,11 +19,10 @@
 
     # Check if the process with the stored PID is running
     expect(Process.kill(0, pid)).to be_truthy
-  end
 
-  after(:all) do
-    process = File.read(ScoutApm::Logging::MonitorManager::PID_FILE).to_i
-    Process.kill('TERM', process)
-    File.delete(ScoutApm::Logging::MonitorManager::PID_FILE)
+    # Kill the process and ensure PID file clean up
+    Process.kill('TERM', pid)
+    sleep 1 # Give the process time to exit
+    expect(File.exist?(ScoutApm::Logging::MonitorManager::PID_FILE)).to be_falsey
   end
 end