Chapter 1. Service binding

1. Install the Service Binding Operator version 1.3.3 and higher using the Installing the Service Binding Operator from the OpenShift Container Platform web UI procedure.

   1. Verify the installation:

      oc get csv -w

      Proceed to the next step when the phase of the Service Binding Operator is set to Succeeded.

2. Install the Crunchy PostgreSQL Operator from OperatorHub by using either the web console or CLI.

   1. Verify the installation:

      oc get csv -w

      Proceed to the next step when the operator’s phase is set to Succeeded.

3. Create a PostgreSQL cluster:

   1. Create a new OpenShift Container Platform namespace, which will be used for creating a cluster and deploying your application later. This namespace will be referred to as demo throughout the procedure.

      oc new-project demo

   2. Create the following custom resource and save it as pg-cluster.yml:

      apiVersion: postgres-operator.crunchydata.com/v1beta1
      kind: PostgresCluster
      metadata:
        name: hippo
      spec:
        openshift: true
        image: registry.developers.crunchydata.com/crunchydata/crunchy-postgres:ubi8-14.2-1
        postgresVersion: 14
        instances:
          - name: instance1
            dataVolumeClaimSpec:
              accessModes:
              - "ReadWriteOnce"
              resources:
                requests:
                  storage: 1Gi
        backups:
          pgbackrest:
            image: registry.developers.crunchydata.com/crunchydata/crunchy-pgbackrest:ubi8-2.38-0
            repos:
            - name: repo1
              volume:
                volumeClaimSpec:
                  accessModes:
                  - "ReadWriteOnce"
                  resources:
                    requests:
                      storage: 1Gi

      Note

      This YAML has been reused from Service Binding Operator Quickstart.

   3. Apply the created custom resource:

      oc apply -f ~/pg-cluster.yml

      Note

      This command assumes that you saved the pg-cluster.yml file in the HOME directory.

   4. Check the pods to verify the installation:

      oc get pods -n demo

      • Wait for the Pods to enter the READY state, indicating the installation is complete.

4. Create a Quarkus application that binds to the PostgreSQL database.

   The application you are creating is a basic todo application that connects to PostgreSQL using Hibernate and Panache.

   1. Generate the application:

      mvn com.redhat.quarkus.platform:quarkus-maven-plugin:3.8.6.redhat-00004:create \
        -DplatformGroupId=com.redhat.quarkus.platform \
        -DplatformVersion=3.8.6.redhat-00004 \
        -DprojectGroupId=org.acme \
        -DprojectArtifactId=todo-example \
        -DclassName="org.acme.TodoResource" \
        -Dpath="/todo"

   2. Add all required extensions for connecting to PostgreSQL, generating all required resources, and building a container image for our application:

      ./mvnw quarkus:add-extension -Dextensions="resteasy-reactive-jackson,jdbc-postgresql,hibernate-orm-panache,openshift,kubernetes-service-binding"

   3. Create a simple entity, as outlined in the following example:

      package org.acme;
      
      import jakarta.persistence.Column;
      import jakarta.persistence.Entity;
      
      import io.quarkus.hibernate.orm.panache.PanacheEntity;
      
      @Entity
      public class Todo extends PanacheEntity {
      
          @Column(length = 40, unique = true)
          public String title;
      
          public boolean completed;
      
          public Todo() {
          }
      
          public Todo(String title, Boolean completed) {
              this.title = title;
          }
      
      }

   4. Expose the entity:

      package org.acme;
      
      import jakarta.transaction.Transactional;
      import jakarta.ws.rs.*;
      import jakarta.ws.rs.core.Response;
      import jakarta.ws.rs.core.Response.Status;
      import java.util.List;
      
         @Path("/todo")
         public class TodoResource {
      
             @GET
             @Path("/")
             public List<Todo> getAll() {
               return Todo.listAll();
             }
      
             @GET
             @Path("/{id}")
             public Todo get(@PathParam("id") Long id) {
                 Todo entity = Todo.findById(id);
                 if (entity == null) {
                     throw new WebApplicationException("Todo with id of " + id + " does not exist.", Status.NOT_FOUND);
                 }
                 return entity;
             }
      
             @POST
             @Path("/")
             @Transactional
             public Response create(Todo item) {
                 item.persist();
                 return Response.status(Status.CREATED).entity(item).build();
             }
      
             @GET
             @Path("/{id}/complete")
             @Transactional
             public Response complete(@PathParam("id") Long id) {
                 Todo entity = Todo.findById(id);
                 entity.id = id;
                 entity.completed = true;
                 return Response.ok(entity).build();
             }
      
      
             @DELETE
             @Transactional
             @Path("/{id}")
             public Response delete(@PathParam("id") Long id) {
                 Todo entity = Todo.findById(id);
                 if (entity == null) {
                     throw new WebApplicationException("Todo with id of " + id + " does not exist.", Status.NOT_FOUND);
                 }
                 entity.delete();
                 return Response.noContent().build();
             }
      
         }

5. Bind to the target PostgreSQL cluster by generating a ServiceBinding resource.

   1. Provide the service coordinates to generate the binding and configure the data source:

      • apiVersion: postgres-operator.crunchydata.com/v1beta1
      • kind: PostgresCluster

      • name: pg-cluster

        This is accomplished by setting a quarkus.kubernetes-service-binding.services.<id>. prefix, as demonstrated in the example below. The id is used to group properties together and can be assigned any value.

        quarkus.kubernetes-service-binding.services.my-db.api-version=postgres-operator.crunchydata.com/v1beta1
        quarkus.kubernetes-service-binding.services.my-db.kind=PostgresCluster
        quarkus.kubernetes-service-binding.services.my-db.name=hippo
        
        quarkus.datasource.db-kind=postgresql
        quarkus.hibernate-orm.database.generation=drop-and-create
        quarkus.hibernate-orm.sql-load-script=import.sql

   2. Create an import.sql script with some initial data:

      INSERT INTO todo(id, title, completed) VALUES (nextval('hibernate_sequence'), 'Finish the blog post', false);

6. Deploy the application, including ServiceBinding, and apply it to the cluster:

   mvn clean install -Dquarkus.kubernetes.deploy=true -DskipTests

   Wait for the deployment to finish.

Verification

1. Verify the deployment:

   oc get pods -n demo -w

2. Verify the installation:

   1. Port forward to the HTTP port locally, and then access the /todo endpoint.

      oc port-forward service/todo-example 8080:80

   2. Open the following URL in a web browser:

      http://localhost:8080/todo