Sub)

Django Action Triggers sending messages to a GCP Pub/Sub message broker. This section guides you through configuring GCP Pub/Sub and creating triggers that send messages to a GCP Pub/Sub broker.

Installation

To use GCP Pub/Sub as a message broker, you will need to install an additional package. This can be done by running the following command:

pip install django-action-triggers[gcp]

Configuration

Before messages can be sent to a GCP Pub/Sub message broker, the broker needs to be configured in the Django settings.

Note

See the message brokers configuration guide for information on configuring message brokers.

GCP Pub/Sub Configuration

The following configuration options must be set in the Django settings to configure the GCP Pub/Sub message broker:

conn_details.project: The GCP project name.
conn_details.topic: The topic where messages will be sent when a trigger is activated.

Example Configuration in settings.py

Here is an example configuration for GCP Pub/Sub:

ACTION_BROKERS = {
  "my_gcp_pubsub_broker": {
    "broker_type": "gcp_pubsub",
    "conn_details": {
      "project": "my-gcp-project",
      "topic": "my_topic"
    },
    "params": {}
  }
}

In this configuration: - The my_gcp_pubsub_broker is set to connect to the GCP project my-gcp-project and send messages to the my_topic topic.

Creating a GCP Pub/Sub Action

Once you have configured GCP Pub/Sub, you can create a trigger that sends messages to the GCP Pub/Sub broker whenever the trigger is activated.

Scenario

Suppose you have the following Django models:

from django.db import models

class Customer(models.Model):
  name = models.CharField(max_length=255)
  email = models.EmailField()

class Product(models.Model):
    name = models.CharField(max_length=255)
    description = models.TextField()


class Sale(models.Model):
    customer = models.ForeignKey(Customer, on_delete=models.CASCADE)
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    quantity = models.IntegerField()

Let’s say you want to send a message to GCP Pub/Sub when a new sale is created. You can achieve this by following these steps:

Step 1: Create a Config Model Instance (Base Action)

The Config model defines the base action, including the payload that will be sent when the trigger is activated.

from django.contrib.contenttypes.models import ContentType
from action_triggers.models import Config

config = Config.objects.create(
  payload={
    "customer_name": "{{ customer.name }}",
    "product_name": "{{ product.name }}",
    "quantity": "{{ quantity }}"
  },
  active=True,
  content_types=[
    ContentType.objects.get_for_model(Sale)
  ]
)

The payload is designed to behave like a Django template. If the resulting value is JSON-serializable, the payload will be returned as JSON; otherwise, it will be returned as plain text.

Step 2: Create a MessageBrokerQueue Model Instance (GCP Pub/Sub Action)

Now, create a MessageBrokerQueue model instance to define the GCP Pub/Sub action.

from action_triggers.models import MessageBrokerQueue

gcp_pubsub_action = MessageBrokerQueue.objects.create(
  config=config,
  name="my_gcp_pubsub_broker",
  conn_details={
    "project": "my-gcp-project",
    "topic": "my_topic",
  },
  parameters={}
)

In this example: - The gcp_pubsub_action is set to send messages to the GCP project my-gcp-project and the my_topic topic.

Step 3: Create a ConfigSignal Model Instance (Trigger)

Finally, link the action to a trigger event, such as saving a model instance.

from action_triggers.models import ConfigSignal
from action_triggers.enums import SignalChoices

config_signal = ConfigSignal.objects.create(
  config=config,
  signal=SignalChoices.POST_SAVE,
)

Now, whenever a new sale is created, the GCP Pub/Sub action will be triggered.

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By following these steps, you can configure your project to send messages to GCP Pub/Sub using Django Action Triggers. For more advanced configurations, refer to the related documentation sections.