class Falcon::Service::Virtual

A virtual host is an application bound to a specific authority (essentially a hostname). The virtual controller manages multiple hosts and allows a single server to host multiple applications easily.
Spawns instances of {Proxy} and {Redirect} to handle incoming requests.
A controller which mananages several virtual hosts.

def assume_privileges(path)

@returns [Hash] The environment to use for the spawned process.
@parameter path [String] The path to the application directory.
Drop privileges according to the user and group of the specified path. 
def assume_privileges(path)
	# Process.exec / Process.spawn don't replace the environment but instead update it, so we need to clear out any existing BUNDLE_ variables using `nil` values, which will cause them to be removed from the child environment:
	env = ENV.to_h do |key, value|
		if key.start_with?("BUNDLE_")
			[key, nil]
		else
			[key, value]
		end
	end
	
	env["PWD"] = File.dirname(path)
	
	stat = File.stat(path)
	
	Process::GID.change_privilege(stat.gid)
	Process::UID.change_privilege(stat.uid)
	
	home = Etc.getpwuid(stat.uid).dir
	env["HOME"] = home
	
	return env
end

def setup(container)

@parameter container [Async::Container::Generic]
These processes are gracefully restarted if they are already running.
Setup the container with {Redirect} and {Proxy} child processes. 
def setup(container)
	if proxy = container[:proxy]
		proxy.kill(:HUP)
	end
	
	if redirect = container[:redirect]
		redirect.kill(:HUP)
	end
	
	container.reload do
		evaluator = @environment.evaluator
		falcon_path = evaluator.falcon_path
		
		Console.info(self, "Loading configurations:", paths: evaluator.resolved_configuration_paths)
		
		evaluator.resolved_configuration_paths.each do |path|
			path = File.expand_path(path)
			root = File.dirname(path)
			
			spawn(path, container, chdir: root)
		end
		
		container.spawn(name: "Falcon Redirector", restart: true, key: :redirect) do |instance|
			instance.exec(falcon_path, "redirect",
				"--bind", evaluator.bind_insecure,
				"--timeout", evaluator.timeout.to_s,
				"--redirect", evaluator.bind_secure,
				*evaluator.configuration_paths, ready: false
			)
		end
		
		container.spawn(name: "Falcon Proxy", restart: true, key: :proxy) do |instance|
			instance.exec(falcon_path, "proxy",
				"--bind", evaluator.bind_secure,
				"--timeout", evaluator.timeout.to_s,
				*evaluator.configuration_paths, ready: false
			)
		end
	end
end

def spawn(path, container, **options)

@parameter options [Options] The options which are passed to `exec`.
@parameter container [Async::Container::Generic] The container to spawn into.
@parameter path [String] The path to the application directory.
Spawn an application instance from the specified path. 
def spawn(path, container, **options)
	container.spawn(name: "Falcon Application", restart: true, key: path) do |instance|
		env = assume_privileges(path)
		
		instance.exec(env, "bundle", "exec", path, ready: false, **options)
	end
end