circuits.app.daemon module

Daemon Component

Component to daemonize a system into the background and detach it from its controlling PTY. Supports PID file writing, logging stdin, stdout and stderr and changing the current working directory.

class circuits.app.daemon.daemonize(*args, **kwargs)

Bases: circuits.core.events.Event

daemonize Event

An event is a message send to one or more channels. It is eventually dispatched to all components that have handlers for one of the channels and the event type.

All normal arguments and keyword arguments passed to the constructor of an event are passed on to the handler. When declaring a handler, its argument list must therefore match the arguments used for creating the event.

Every event has a name attribute that is used for matching the event with the handlers.

Variables:

• channels –

  an optional attribute that may be set before firing the event. If defined (usually as a class variable), the attribute specifies the channels that the event should be delivered to as a tuple. This overrides the default behavior of sending the event to the firing component’s channel.

  When an event is fired, the value in this attribute is replaced for the instance with the channels that the event is actually sent to. This information may be used e.g. when the event is passed as a parameter to a handler.

• value – this is a circuits.core.values.Value object that holds the results returned by the handlers invoked for the event.
• success – if this optional attribute is set to True, an associated event success (original name with “_success” appended) will automatically be fired when all handlers for the event have been invoked successfully.
• success_channels – the success event is, by default, delivered to same channels as the successfully dispatched event itself. This may be overridden by specifying an alternative list of destinations using this attribute.
• complete – if this optional attribute is set to True, an associated event complete (original name with “_complete” appended) will automatically be fired when all handlers for the event and all events fired by these handlers (recursively) have been invoked successfully.
• complete_channels – the complete event is, by default, delivered to same channels as the initially dispatched event itself. This may be overridden by specifying an alternative list of destinations using this attribute.

name = 'daemonize'

class circuits.app.daemon.deletepid(*args, **kwargs)

Bases: circuits.core.events.Event

“deletepid Event

An event is a message send to one or more channels. It is eventually dispatched to all components that have handlers for one of the channels and the event type.

All normal arguments and keyword arguments passed to the constructor of an event are passed on to the handler. When declaring a handler, its argument list must therefore match the arguments used for creating the event.

Every event has a name attribute that is used for matching the event with the handlers.

Variables:

• channels –

  an optional attribute that may be set before firing the event. If defined (usually as a class variable), the attribute specifies the channels that the event should be delivered to as a tuple. This overrides the default behavior of sending the event to the firing component’s channel.

  When an event is fired, the value in this attribute is replaced for the instance with the channels that the event is actually sent to. This information may be used e.g. when the event is passed as a parameter to a handler.

• value – this is a circuits.core.values.Value object that holds the results returned by the handlers invoked for the event.
• success – if this optional attribute is set to True, an associated event success (original name with “_success” appended) will automatically be fired when all handlers for the event have been invoked successfully.
• success_channels – the success event is, by default, delivered to same channels as the successfully dispatched event itself. This may be overridden by specifying an alternative list of destinations using this attribute.
• complete – if this optional attribute is set to True, an associated event complete (original name with “_complete” appended) will automatically be fired when all handlers for the event and all events fired by these handlers (recursively) have been invoked successfully.
• complete_channels – the complete event is, by default, delivered to same channels as the initially dispatched event itself. This may be overridden by specifying an alternative list of destinations using this attribute.

name = 'deletepid'

class circuits.app.daemon.writepid(*args, **kwargs)

Bases: circuits.core.events.Event

“writepid Event

An event is a message send to one or more channels. It is eventually dispatched to all components that have handlers for one of the channels and the event type.

All normal arguments and keyword arguments passed to the constructor of an event are passed on to the handler. When declaring a handler, its argument list must therefore match the arguments used for creating the event.

Every event has a name attribute that is used for matching the event with the handlers.

Variables:

• channels –

  an optional attribute that may be set before firing the event. If defined (usually as a class variable), the attribute specifies the channels that the event should be delivered to as a tuple. This overrides the default behavior of sending the event to the firing component’s channel.

  When an event is fired, the value in this attribute is replaced for the instance with the channels that the event is actually sent to. This information may be used e.g. when the event is passed as a parameter to a handler.

• value – this is a circuits.core.values.Value object that holds the results returned by the handlers invoked for the event.
• success – if this optional attribute is set to True, an associated event success (original name with “_success” appended) will automatically be fired when all handlers for the event have been invoked successfully.
• success_channels – the success event is, by default, delivered to same channels as the successfully dispatched event itself. This may be overridden by specifying an alternative list of destinations using this attribute.
• complete – if this optional attribute is set to True, an associated event complete (original name with “_complete” appended) will automatically be fired when all handlers for the event and all events fired by these handlers (recursively) have been invoked successfully.
• complete_channels – the complete event is, by default, delivered to same channels as the initially dispatched event itself. This may be overridden by specifying an alternative list of destinations using this attribute.

name = 'writepid'

class circuits.app.daemon.Daemon(*args, **kwargs)

Bases: circuits.core.components.Component

Daemon Component

Parameters:

• pidfile (str or unicode) – .pid filename
• stdin (str or unicode) – filename to log stdin
• stdout (str or unicode) – filename to log stdout
• stderr (str or unicode) – filename to log stderr

initializes x; see x.__class__.__doc__ for signature

channel = 'daemon'

init(pidfile, path='/', stdin=None, stdout=None, stderr=None, channel='daemon')

deletepid()

writepid()

daemonize()

registered(component, manager)

on_started(component)