Passenger
Passenger defines a data type to travel between systems. If you are pulling E-Mails and forwarding them to your target system, E-Mail is your passenger.
General structure of a passenger can be seen under /databus/passenger/abstract_passenger.py . Each passenger implementation has to be a class derived from that.
You can find some demo implementations under databus/passenger/demo, or check "Used by" to see real life examples.
Properties
A passenger will have the following properties:
- external_id: The unique ID given by the source system.
- internal_id: A unique ID given by Databus.
- source_system: Name of the system from which the passenger has been pulled.
- attachments: A list of attachments (see below for details).
- puller_module: Name of the Python module which pulled the passenger.
- pull_datetime: The date + time on which the passenger was pulled.
- log_guids: List of log ID's linked to this passenger
Attachments
Except the properties mentioned above, any data that needs to be stored with the passenger can be added as an attachment. Databus supports text and binary attachments.
For example; if you got an E-Mail message, each attachment can obviously be added as a passenger attachment. But if you need to store the mail body as well, you can add it as an artificial attachment called _body.html .
Or, if you need to store additional properties with the passenger, create an artificial attachment called _props.json and store it as an attachment.
Each attachment of a given passenger must have a unique name.
Supplied passengers
Currently, Databus provides a passenger class for E-Mail messages under databus/passenger/email.py . If you need to pull E-Mails from a mail server, you can use this passenger. Hint: It also has an Exchange Server puller to help you with that.
Implementing a new passenger
- Create a new class derived from databus.passenger.abstract_passenger
- Ensure that your .py file has only one class (which is the passenger)
- Ensure calling super().init()
- You may need to implement corresponding puller / processor / pusher classes as well
- Add the puller class to your client configuration