Configuring Baroque

Baroque behaviour can be easily configured

Default configuration

The default configuration is stored in module:

baroque.defaults.config

as a Python dictionary and is loaded upon broker instantiation if no custom configuration file is provided as argument.

An actual YML version of the default version is stored in the root path of Baroque’s installation (file: _baroque.yml_)

Custom configuration

Custom configurations can be provided as YML files, and can be loaded upon broker instantiation as follows:

from baroque import Baroque
brq = Baroque(configfile='path/to/file.yml')

Baroque validates the YML syntax, but performs no validation on the provided configuration switches (whether they make sense or not): the check is done in a lazy way - in other when the switches are actually used.

Configuration switches

Switches are grouped according to Baroque’s data entities they impact:

• Event Types

  • ignore_unregistered: shall Baroque ignore upon events publication all the events with a type that is not registered? If not, then raise an exception [boolean]
  • pre_registered: this is the list of _EventType_ subclasses that are pre-registered on the broker right from the start, so that it is possible to publish on the broker events of those types without further hassle [list of str, each one being a dotted Python class path]

• Events

  • validate_schema: shall Baroque validate event type schema upon all events upon publishing? If not, raise an exception [boolean]
  • persist: Shall Baroque persist all published events on the provided persistence provider? [boolean]
  • persistence_provider: this is the class implementing events persistence. Must be a subtype of baroque.backend.PersistenceBackend asbtract class [str, dotted Python class path]

• Reactors

  • propagate_exceptions: shall Baroque bubble up exceptions raised by any reactor whenever they occur? If not, catch them silently [boolean]

• Topics

  • register_on_binding: shall Baroque register a previously unregistered topic whenever a reactor is bound to it? If not, raise an exception [boolean]

Example of YML config file contents

This is an example of a possible YML file contents:

eventtypes:
  ignore_unregistered: false
  pre_registered:
    - baroque.entities.eventtype.GenericEventType
    - baroque.entities.eventtype.StateTransitionEventType
    - baroque.entities.eventtype.DataOperationEventType
    - baroque.entities.eventtype.MetricEventType
events:
  validate_schema: true
  persist: false
  persistence_backend: baroque.persistence.inmemory.DictBackend
reactors:
  propagate_exceptions: true
topics:
  register_on_binding: true