Return system as down when the lock file is stale (older than 2 hours)

Author: rafaelfranca

config.ru

@@ -15,6 +15,7 @@ end
 use Rack::CommonLogger, logger
 
 run_file  = ENV["RUN_FILE"] || "#{__dir__}/run-rails-master-hook"
+lock_file = ENV["LOCK_FILE"]
 scheduled = <<EOS
 Rails master hook tasks scheduled:
 
@@ -29,6 +30,24 @@ If a new stable tag is detected it also
 This needs typically a few minutes.
 EOS
 
+# Helper class for lockfile checking
+class LockfileChecker
+  def self.stale?(lock_file, logger)
+    return false unless lock_file && File.exist?(lock_file)
+
+    file_age = Time.now - File.mtime(lock_file)
+    stale = file_age > 7200 # 2 hours in seconds
+
+    if stale
+      logger.warn "Lock file #{lock_file} is stale (age: #{(file_age / 60).round(1)} minutes)"
+    else
+      logger.debug "Lock file #{lock_file} age: #{(file_age / 60).round(1)} minutes"
+    end
+
+    stale
+  end
+end
+
 map "/rails-master-hook" do
   run ->(env) do
     request_method = env["REQUEST_METHOD"]
@@ -47,6 +66,13 @@ end
 
 map "/" do
   run ->(_env) do
-    [200, {"Content-Type" => "text/plain", "Content-Length" => "4"}, ["PONG"]]
+    # Check if lockfile is stale (older than 2 hours)
+    if LockfileChecker.stale?(lock_file, logger)
+      error_msg = "System down: Lock file has been present for more than 2 hours"
+      logger.error error_msg
+      [503, {"Content-Type" => "text/plain", "Content-Length" => error_msg.length.to_s}, [error_msg]]
+    else
+      [200, {"Content-Type" => "text/plain", "Content-Length" => "4"}, ["PONG"]]
+    end
   end
 end

config/deploy/production.rb

@@ -8,6 +8,7 @@
 
 set :puma_service_unit_env_vars, %w[
   RUN_FILE=/home/rails/rails-master-hook/run-rails-master-hook
+  LOCK_FILE=/home/rails/rails-master-hook/lock-rails-master-hook
 ]
 set :puma_access_log, "journal"
 set :puma_error_log, "journal"