Add health_check_timeout for detecting hung servers.

Author: ioquatix

falcon.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |spec|
 	spec.required_ruby_version = ">= 3.1"
 
 	spec.add_dependency "async"
-	spec.add_dependency "async-container", "~> 0.18"
+	spec.add_dependency "async-container", "~> 0.20"
 	spec.add_dependency "async-http", "~> 0.75"
 	spec.add_dependency "async-http-cache", "~> 0.4"
 	spec.add_dependency "async-service", "~> 0.10"

lib/falcon/command/serve.rb

@@ -45,10 +45,12 @@ class Serve < Samovar::Command
 
 				option "--[no]-restart", "Enable/disable automatic restart.", default: true
 				option "--graceful-stop <timeout>", "Duration to wait for graceful stop.", type: Float, default: 1.0
+				
+				option "--health-check-timeout <duration>", "Duration to wait for health check.", type: Float, default: 30.0
 			end
 
 			def container_options
-				@options.slice(:count, :forks, :threads, :restart)
+				@options.slice(:count, :forks, :threads, :restart, :health_check_timeout)
 			end
 
 			def endpoint_options

lib/falcon/environment/server.rb

@@ -33,7 +33,7 @@ def count
 
 			# Options to use when creating the container.
 			def container_options
-				{restart: true, count: self.count}.compact
+				{restart: true, count: self.count, health_check_timeout: 30}.compact
 			end
 
 			# The host that this server will receive connections for.

lib/falcon/service/server.rb

@@ -52,6 +52,7 @@ def start
 			# @parameter container [Async::Container::Generic]
 			def setup(container)
 				container_options = @evaluator.container_options
+				health_check_timeout = container_options[:health_check_timeout]
 
 				container.run(name: self.name, **container_options) do |instance|
 					evaluator = @environment.evaluator
@@ -63,6 +64,16 @@ def setup(container)
 
 						instance.ready!
 
+						if health_check_timeout
+							Async(transient: true) do
+								while true
+									instance.name = "#{server} load=#{Fiber.scheduler.load}"
+									sleep(health_check_timeout / 2)
+									instance.ready!
+								end
+							end
+						end
+						
 						task.children.each(&:wait)
 					end
 				end