In the latest release of IBM® App Connect on IBM Cloud™ – Custom Enterprise, Cloud Connector and Lite plans – we’ve expanded the callable flow function so that IBM App Connect on IBM Cloud flows can be exposed as callable flows. This opens up the massive collection of App Connect applications to IBM App Connect Enterprise and IBM Integration Bus flows. So it’s now simple for App Connect Enterprise or Integration Bus flows to make use of any of the actions that are available in your App Connect on IBM Cloud applications. This, combined with the existing ability for App Connect on IBM Cloud flows to call App Connect Enterprise or Integration Bus flows, allows for seamless hybrid integration where it is easy to construct integrations that combine function in the cloud and on-premises.
As an example, let’s imagine you want to create an integration that:
- Receives data from SAP in the form of a BAPI.
- Enriches that data with a lookup to an Oracle database.
- Uses part of the data to update Marketo.
- Uses part of the data to update Eventbrite.
- Uses the results from Marketo and Eventbrite to create a response to the BAPI call.
You can start by constructing a flow in App Connect on IBM Cloud that uses a “Callable flow” event to trigger the update actions in Marketo and Eventbrite. Next, create an App Connect Enterprise or Integration Bus flow that has SAP as an input, and then a database lookup, followed by a callable flow that invokes the App Connect on IBM Cloud flow, and finally, an SAP reply node. Deploy and start both flows, and the full hybrid integration will be up and running!
Exposing an App Connect on IBM Cloud flow as a callable flow
Let’s briefly explore how to expose an App Connect on IBM Cloud flow as a callable flow.
- From the flow editor of a new flow in App Connect on IBM Cloud, go to the Toolbox tab.
- Select Callable flow as the event that triggers the flow.Note: A callable reply node is automatically added to the flow and can be used to construct a reply to return to the calling flow.
- Insert any actions that you want to perform between the event node and the reply node.
You can call this callable flow from an App Connect Enterprise or Integration Bus flow by using an application name that is identical to the App Connect on IBM Cloud flow name, with the endpoint name set to default.
There’s no need to copy any definitions from App Connect Enterprise or Integration Bus to App Connect on IBM Cloud, or vice versa. Once the App Connect on IBM Cloud flow is started, it can be discovered and then executed by any flow that’s configured with the correct application name and endpoint name.
For an example that demonstrates an ACE flow calling a flow in App Connect on IBM Cloud, see the tutorial Sharing data and processing from on-premises activities with on-cloud SaaS applications using a callable on-cloud flow.
To find out more about flows in App Connect on IBM Cloud calling flows in ACE or IIB, and a tutorial, see the previous post: IBM App Connect flows can now directly call IBM Integration Bus callable flows.