In addition to grouping multiple components within an application, you can also use the Topology view to connect components with each other. You can either use a binding connector or a visual one to connect components.

A binding connection between the components can be established only if the target node is an Operator-backed service. This is indicated by the Create a binding connector tool-tip which appears when you drag an arrow to such a target node. When an application is connected to a service by using a binding connector a ServiceBinding resource is created. Then, the Service Binding Operator controller projects the necessary binding data into the application deployment. After the request is successful, the application is redeployed establishing an interaction between the connected components.

A visual connector establishes only a visual connection between the components, depicting an intent to connect. No interaction between the components is established. If the target node is not an Operator-backed service the Create a visual connector tool-tip is displayed when you drag an arrow to a target node.

Discovering and identifying Operator-backed bindable services

As a user, if you want to create a bindable service, you must know which services are bindable. Bindable services are services that the applications can consume easily because they expose their binding data such as credentials, connection details, volume mounts, secrets, and other binding data in a standard way. The Developer perspective helps you discover and identify such bindable services.

  • To discover and identify Operator-backed bindable services, consider the following alternative approaches:

    • Click +AddDeveloper CatalogOperator Backed to see the Operator-backed tiles. Operator-backed services that support service binding features have a Bindable badge on the tiles.

    • On the left pane of the Operator Backed page, select the Bindable checkbox.

      Click the help icon next to Service binding to see more information about bindable services.

    • Click +AddAdd and search for Operator-backed services. When you click the bindable service, you can view the Bindable badge in the side panel to the right.

Creating a visual connection between components

You can depict an intent to connect application components by using the visual connector.

This procedure walks you through an example of creating a visual connection between a PostgreSQL Database service and a Spring PetClinic sample application.

  • You have created and deployed a Spring PetClinic sample application by using the Developer perspective.

  • You have created and deployed a Crunchy PostgreSQL database instance by using the Developer perspective. This instance has the following components: hippo-backup, hippo-instance, hippo-repo-host, and hippo-pgbouncer.

  1. Hover over the Spring PetClinic sample application to see a dangling arrow on the node.

    odc connector
    Figure 1. Visual connector
  2. Click and drag the arrow towards the hippo-pgbouncer deployment to connect the Spring PetClinic sample application with it.

  3. Click the spring-petclinic deployment to see the Overview panel. Under the Details tab, click the edit icon in the Annotations section to see the Key = app.openshift.io/connects-to and Value = [{"apiVersion":"apps/v1","kind":"Deployment","name":"hippo-pgbouncer"}] annotation added to the deployment.

  4. Optional: You can repeat these steps to establish visual connections between other applications and components you create.