This class is capable of spawning Ruby on Rails application instances quickly. This is done by preloading the Ruby on Rails framework into memory, before spawning the application instances.
A single FrameworkSpawner instance can only hold a single Ruby on Rails framework version. So be careful when using FrameworkSpawner: the applications that you spawn through it must require the same RoR version. To handle multiple RoR versions, use multiple FrameworkSpawner instances.
FrameworkSpawner uses ApplicationSpawner internally.
Note: FrameworkSpawner may only be started asynchronously with AbstractServer#start. Starting it synchronously with AbstractServer#start_synchronously has not been tested.
Creates a new instance of FrameworkSpawner.
Valid options are:
- :version: The Ruby on Rails version to use. It is not checked whether this version is actually installed.
- :vendor: The directory to the vendor Rails framework to use. This is usually something like "/webapps/foo/vendor/rails".
It is not allowed to specify both version and vendor.
All other options will be passed on to ApplicationSpawner and RequestHandler.
Note that the specified Rails framework will be loaded during the entire life time of the FrameworkSpawner server. If you wish to reload the Rails framework‘s code, then restart the server by calling AbstractServer#stop and AbstractServer#start.
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# File lib/phusion_passenger/railz/framework_spawner.rb, line 64 64: def initialize(options = {}) 65: if !options.respond_to?('[]''[]') 66: raise ArgumentError, "The 'options' argument not seem to be an options hash" 67: end 68: @version = options[:version] 69: @vendor = options[:vendor] 70: if !@version && !@vendor 71: raise ArgumentError, "Either the 'version' or the 'vendor' option must specified" 72: elsif @version && @vendor 73: raise ArgumentError, "It is not allowed to specify both the 'version' and the 'vendor' options" 74: end 75: 76: super() 77: self.max_idle_time = DEFAULT_FRAMEWORK_SPAWNER_MAX_IDLE_TIME 78: define_message_handler(:spawn_application, :handle_spawn_application) 79: define_message_handler(:reload, :handle_reload) 80: end
Remove the cached application instances at the given application root. If nil is specified as application root, then all cached application instances will be removed, no matter the application root.
Long description: Application code might be cached in memory by a FrameworkSpawner. But once it a while, it will be necessary to reload the code for an application, such as after deploying a new version of the application. This method makes sure that any cached application code is removed, so that the next time an application instance is spawned, the application code will be freshly loaded into memory.
Raises:
- ArgumentError: app_root doesn‘t appear to be a valid Ruby on Rails application root.
- FrameworkSpawner::Error: The FrameworkSpawner server exited unexpectedly.
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# File lib/phusion_passenger/railz/framework_spawner.rb, line 199 199: def reload(app_root = nil) 200: if app_root.nil? 201: server.write("reload") 202: else 203: server.write("reload", normalize_path(app_root)) 204: end 205: rescue SystemCallError, IOError, SocketError 206: raise Error, "The framework spawner server exited unexpectedly" 207: end
Spawn a RoR application using the Ruby on Rails framework version associated with this FrameworkSpawner. When successful, an Application object will be returned, which represents the spawned RoR application.
The following options are allowed:
- lower_privilege and lowest_user: If
lower_privilege is true, then ApplicationSpawner will attempt to
switch to the user who owns the application‘s
config/environment.rb, and to the default group of that user.
If that user doesn‘t exist on the system, or if that user is root, then ApplicationSpawner will attempt to switch to the username given by lowest_user (and to the default group of that user). If lowest_user doesn‘t exist either, or if switching user failed (because the current process does not have the privilege to do so), then ApplicationSpawner will continue without reporting an error.
- environment: Allows one to specify the RAILS_ENV environment to use.
All other options will be passed on to ApplicationSpawner and RequestHandler.
FrameworkSpawner will internally cache the code of applications, in order to speed up future spawning attempts. This implies that, if you‘ve changed the application‘s code, you must do one of these things:
- Restart this FrameworkSpawner by calling AbstractServer#stop, then AbstractServer#start.
- Reload the application by calling reload with the correct app_root argument.
Raises:
- AbstractServer::ServerNotStarted: The FrameworkSpawner server hasn‘t already been started.
- InvalidAppRoot: app_root doesn‘t appear to be a valid Ruby on Rails application root.
- AppInitError: The application raised an exception or called exit() during startup.
- ApplicationSpawner::Error: The ApplicationSpawner server exited unexpectedly.
- FrameworkSpawner::Error: The FrameworkSpawner server exited unexpectedly.
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# File lib/phusion_passenger/railz/framework_spawner.rb, line 150 150: def spawn_application(app_root, options = {}) 151: app_root = normalize_path(app_root) 152: assert_valid_app_root(app_root) 153: options = sanitize_spawn_options(options) 154: options["app_root"] = app_root 155: 156: exception_to_propagate = nil 157: begin 158: server.write("spawn_application", *options.to_a.flatten) 159: result = server.read 160: if result.nil? 161: raise IOError, "Connection closed" 162: end 163: if result[0] == 'exception' 164: e = unmarshal_exception(server.read_scalar) 165: if e.respond_to?(:child_exception) && e.child_exception 166: #print_exception(self.class.to_s, e.child_exception) 167: end 168: raise e 169: else 170: pid, listen_socket_name, socket_type = server.read 171: if pid.nil? 172: raise IOError, "Connection closed" 173: end 174: owner_pipe = server.recv_io 175: return Application.new(app_root, pid, listen_socket_name, 176: socket_type, owner_pipe) 177: end 178: rescue SystemCallError, IOError, SocketError => e 179: raise Error, "The framework spawner server exited unexpectedly" 180: end 181: end
Overrided from AbstractServer#start.
May raise these additional exceptions:
- FrameworkInitError: The specified Ruby on Rails framework could not be loaded.
- FrameworkSpawner::Error: The FrameworkSpawner server exited unexpectedly.
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# File lib/phusion_passenger/railz/framework_spawner.rb, line 87 87: def start 88: super 89: begin 90: result = server.read 91: if result.nil? 92: raise Error, "The framework spawner server exited unexpectedly." 93: else 94: status = result[0] 95: end 96: if status == 'exception' 97: child_exception = unmarshal_exception(server.read_scalar) 98: stop 99: if @version 100: message = "Could not load Ruby on Rails framework version #{@version}: " << 101: "#{child_exception.class} (#{child_exception.message})" 102: else 103: message = "Could not load Ruby on Rails framework at '#{@vendor}': " << 104: "#{child_exception.class} (#{child_exception.message})" 105: end 106: options = { :vendor => @vendor, :version => @version } 107: raise FrameworkInitError.new(message, child_exception, options) 108: end 109: rescue IOError, SystemCallError, SocketError 110: stop 111: raise Error, "The framework spawner server exited unexpectedly" 112: end 113: end