Interface for Notification Service

[dread]

Use cases

• Registration
• Deregistration
• Configuration of port in pylons config

Design

• Default port: 5672 (standard for AMQP)
• Exchange name: 'ckan'
• Exchange type: topic exchange (most flexible)
• Routing keys: (see below)

Routing detail

Routing key format: "OBJ_TYPE.OBJ_ID.CHANGE_TYPE" (NB tags should be identified by their name, not ID)

Example routing keys

• 'package.238bc-704a87-928374.new' - New package created with ID '238bc-704a87-928374'
• 'group.4234-ab98203-fe324.edited' - Group '4234-ab98203-fe324' edited
• 'tag.704a8-2f38bc-928374.' - New package created with ID '238bc-704a87-928374'

Example queue bindings that clients may use:

• * - no filtering - client receives all notifications
• package.* - only changes to packages
• package.238bc-704a87-928374.* - only changes to a particular package
• package.#.new - only packages creations

Versioning

Since message payloads will be tied into the REST Entities, it makes sense to join up with the REST versioning. This could be achieved by providing new exchanges called 'ckan-1.1' perhaps?

Documentation

• How to use
• simple example of an external client?