Integrating NATS Messaging with Orkes Conductor

This developer guide includes the steps to integrate NATS Messaging with Orkes Conductor. This integration lets you connect your NATS server to Conductor to publish and receive messages from queues.

Get Configuration Credentials from NATS Messaging

Pre-Requisites

You must set up NATS messaging before integrating with Orkes Conductor. Refer to the NATS Messaging official documentation for more details.

Get the following credentials from the NATS server:

• Server name
• Username & password if you prefer to authenticate with credentials.

Integrating with NATS Messaging as a Message Broker

Once you have the required configuration credentials from NATS Messaging, let’s integrate with Orkes Conductor.

1. Navigate to Integrations from the left menu on the Conductor cluster.
2. Click + New integration from the top-right corner of your window.
3. Under the Message Broker section, choose NATS Messaging.
4. Click +Add and provide the following parameters:

Paremeters	Description
Integration Name	A name to identify your integration.
Server	Provide the NATS server name to be integrated with Orkes Conductor.
Connection Type	Choose the required connection type for the integration. It can take two values: Default Jetstream
Authentication Type	Choose the required authentication type. You can opt for With Credentials or Without Credentials.
Username	Provide the username for authentication. This field is required only if the Authentication Type is chosen as With Credentials.
Password	Provide the password for authentication. This field is required only if the Authentication Type is chosen as With Credentials.
Description	Provide a description of the integration.

5. You can toggle on the Active button to activate the integration instantly.
6. Click Save.

Creating Event Handlers in Orkes Conductor

The integration is created successfully now. The next step is to create an event handler in Orkes Conductor.

To do this:

1. Navigate to Definitions > Event Handler from the left menu on your Conductor console.
2. Click the + Define event handler option from the top-right corner of the window.
3. Create an event handler with the following configurations:

Event Handler Parameters	Description
Name	Provide a name to identify your event handler definition.
Event	Provide the event integration you have created in the following format: Type : Config Name : Queue Name Example: nats:nats-test:queue-name Notes: The drop-down automatically lists the integration you’ve added to the Conductor cluster. You can choose that and add the queue name you want to publish/receive messages.
Condition	Provide the ECMAScript to control the message processing if required. Check out the event handler documentation for more details.
Actions	Choose the required actions to be carried out on sending/receiving the events from NATS. It can take the following values: Complete Task Terminate Workflow Update Variables Fail Task Start Workflow Each type of action requires and supports a certain set of input parameters. Check out the event handler documentation for more details.
Active	Set this to true or false. It determines if the event handler is running or not.

A sample JSON for the event handler is as follows:

{
 "name": "nats-userpass",
 "event": "nats:natstest:events-test-1.test",
 "condition": "true",
 "actions": [
   {
     "action": "start_workflow",
     "start_workflow": {
       "name": "event-handler-test",
       "version": 1,
       "correlationId": "",
       "input": {
         "payload": "${$}"
       }
     },
     "expandInlineJSON": false
   }
 ],
 "active": true,
 "evaluatorType": "javascript"
}

RBAC - Governance on who can use Integrations

Once the integration is added, the next step is determining who can access these integrations.

The permissions can be granted to applications/groups within the Orkes Conductor cluster.

To provide explicit permission to Groups:

1. From the left menu on your Conductor cluster, navigate to Access Control > Groups.
2. Create a new group or choose an existing group.
3. Under the Permissions section, click +Add Permission.
4. From the Integrations sub-tab, choose the integration with required permissions.
5. Click Add Permissions. This ensures that all the group members can access these integration models in their workflows.

Similarly, you can also provide permissions to applications.

Creating Workflow in Orkes Conductor

This step involves creating a workflow with an event task in Orkes Conductor. Here, we are utilizing the NATS queue as a sink for the event.

You can quickly build a workflow from UI in Orkes Conductor.

For this,

1. Navigate to Definitions > Workflow, and click the Define Workflow button.
2. Create a workflow and add an event task at the required point with the Sink in the format nats:Nats-integration-test:queue-name, where “Nats-integration-test” is the integration name and “queue-name” is the queue to which Conductor should send/receive messages.

Executing Workflow in Orkes Conductor

The workflow can be run using different methods. You can use the Run Workflow button for quick testing, as shown in the image below:

Upon successful execution, you can verify the message's delivery through the NATS server.

Check out the official NATS documentation on enabling monitoring & how to monitor the NATS messaging system.

The action added in the event handler definition was to start the workflow event-handler-test. You can verify the same from the Executions > Workflow page.