Publishing virtual topics

After adding your source topic and creating a virtual topic, you can publish your virtual topic to a set of gateway groups which will make it available in the catalog.

You can publish virtual topics to the Event Endpoint Management catalog, IBM API Connect Developer Portal, or both. All published virtual topics are displayed in the selected destination, along with source topic name, tags, and status information. The source topic owner can edit or delete their virtual topics after publishing them, as described in managing virtual topics.

Users can then discover available virtual topics and subscribe to them.

Before you begin

A gateway is required to publish a virtual topic. Ensure that you have at least one gateway group associated with your Event Manager instance. For more information, see managing gateways.

To publish virtual topics to the Developer Portal ensure that the following prerequisites are in place:

  • Developer Portal is installed in IBM API Connect and is accessible.
  • The integration between Event Endpoint Management and Developer Portal is configured.
  • The virtual topic is configured with an authentication set that uses SASL credentials.
  • The virtual topic has the Require approval toggle set to Off.

Publishing virtual topics

To publish a virtual topic, complete the following steps:

  1. Log in to the Event Endpoint Management UI by using your login credentials.
  2. In the navigation pane, click Manage > Topics. A list of source topics is displayed.
  3. Select the source topic that you want to publish a virtual topic from.
  4. Click the Virtual topics tab.
  5. For the virtual topic that you want to publish, click Publish.

  6. In the Publish virtual topic dialog, configure the following settings:

    • Gateway group: Select a gateway group from the available options.

      Note:

      • When only one gateway is available, it is selected by default. If you have multiple gateways, you can choose a gateway group from the available options.
      • Some controls require a supported gateway. If you attempt to publish a virtual topic to a gateway that does not support specific controls, a notification is displayed to inform you that this action is not possible.
      • You can only publish virtual topics to gateway groups that contain a gateway that has passed the validation checks for the cluster and source topic.
      • The target gateway group must have enough hostnames to match the number of brokers across all Kafka clusters that all the topics published to this gateway group use.

    • Publishing destination: Select where you want to publish the virtual topic:

      • Event Endpoint Management catalog: Publish to the Event Endpoint Management catalog only.
      • Developer Portal: Publish to IBM API Connect Developer Portal only.
      • Both: Publish to both the Event Endpoint Management catalog and Developer Portal.
  7. Click Publish.

Viewing published virtual topics

After the virtual topic is published, users can discover and learn more about the corresponding virtual topic in the Event Endpoint Management catalog.

To view the virtual topic within the Event Endpoint Management catalog, complete the following steps:

  1. Log in to the Event Endpoint Management UI by using your login credentials.
  2. In the navigation pane, click Catalog.
  3. Select the source topic that the virtual topic belongs to from the list.
  4. Select the virtual topic card in the Virtual topics section.

After you select a virtual topic, you can view the description and event information. Based on this information, you can subscribe to the virtual topic to get access. You can also export a virtual topic as an AsyncAPI document.

Viewing published virtual topics in Developer Portal

After the virtual topic is published, users can discover and subscribe to the corresponding virtual topic in the Developer Portal interface.

  1. Log in to Developer Portal.
  2. Go to the Asset gallery.
  3. Search for the published virtual topic that you want to work with.
  4. Click on the virtual topic to view its details, including:
    • Description and documentation
    • Schema information
    • Sample messages
    • Code accelerator samples
    • Subscription options

Users can then subscribe to the virtual topic to obtain credentials to access it.