nameko-eventlog-dispatcher 0.1.0

Nameko dependency provider that dispatches log data using Events (Pub-Sub).

Nameko dependency provider that dispatches log data using Events (Pub-Sub).

Usage

Dispatching event log data

Include the EventLogDispatcher dependency in your service class:

from nameko.rpc import rpc
from nameko_eventlog_dispatcher import EventLogDispatcher


class FooService:

    name = 'foo'

    eventlog_dispatcher = EventLogDispatcher()

    @rpc
    def foo_method(self):
        self.eventlog_dispatcher('foo_event_type', {'value': 1})

event_type and some event_data (optional) will be provided as arguments. event_data must contain JSON serializable data.

Calling foo_method will dispatch an event from the foo service with log_event as the event type.

Then, any nameko service will be able to handle this event.

from nameko.events import event_handler


class BarService:

    name = 'bar'

    @event_handler('foo', 'log_event')
    def foo_log_event_handler(self, body):
        """`body` will contain the event log data."""

Capturing log data when entrypoints are fired

Enable auto capture event logs in your nameko configuration file:

# config.yaml

EVENTLOG_DISPATCHER:
  auto_capture: true
  entrypoints_to_exclude: []

With auto_capture set to true, a nameko event will be dispatched every time an entrypoint is fired:

• The source service for these events will be all.

• The event type will be entrypoint_fired.

• Only entrypoints listed in the ENTRYPOINT_TYPES_TO_LOG class attribute will be logged.

• entrypoints_to_exclude can be used to provide a list of entrypoint method names to exclude when firing events automatically.

Then, any nameko service will be able to handle this kind of events:

from nameko.events import event_handler


class BazService:

    name = 'baz'

    @event_handler('all', 'entrypoint_fired')
    def all_entrypoint_fired_event_handler(self, body):
        """Body will contain the event log data."""

Format of the event log data

This is the format of the event log data:

{
  "entrypoint_name": "foo_method",
  "service_name": "foo",
  "timestamp": "2017-06-12T13:48:16+00:00",
  "event_type": "foo_event_type",
  "data": {},
  "call_stack": [
    "standalone_rpc_proxy.call.3f349ea4-ed3e-4a3b-93d0-a36fbf928ecb",
    "bla.bla_method.21d623b4-edc4-4232-9957-4fad72533b75",
    "foo.foo_method.d7e907ee-9425-48a6-84e6-89db19e3ce50"
  ],
  "entrypoint_protocol": "Rpc",
  "call_id": "foo.foo_method.d7e907ee-9425-48a6-84e6-89db19e3ce50"
}

The data attribute will contain the event data that was provided as an argument for the event_data parameter when dispatching the event.

Tests

It is assumed that RabbitMQ is up and running on the default URL guest:guest@localhost and uses the default ports.

$ make test
$ make coverage

A different RabbitMQ URI can be provided overriding the following environment variables: RABBIT_CTL_URI and AMQP_URI.

Additional pytest parameters can be also provided using the ARGS variable.

$ make test RABBIT_CTL_URI=http://guest:guest@dockermachine:15673 AMQP_URI=amqp://guest:guest@dockermachine:5673 ARGS='-x -vv --disable-pytest-warnings'
$ make coverage RABBIT_CTL_URI=http://guest:guest@dockermachine:15673 AMQP_URI=amqp://guest:guest@dockermachine:5673 ARGS='-x -vv --disable-pytest-warnings'