Chapter 1. Service binding

1. Install the Service Binding Operator version 1.0 and higher using the Installing the Service Binding Operator from the OpenShift Container Platform web UI procedure.

   1. Verify the installation:

      oc get csv -n openshift-operators -w

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      • When the phase of the Service Binding Operator is set to Succeeded, proceed to the next step.

2. Install the Crunchy PostgreSQL Operator from OperatorHub by using the web console or CLI. For links to instructions, see the Deploy & use section.

   1. Verify the installation:

      oc get csv -n openshift-operators -w

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      • When the phase of the operator is set to Succeeded, proceed to the next step.

3. Create a PostgreSQL cluster:

   1. Create a new OpenShift Container Platform namespace, in the space of which you will create a cluster and deploy your application later on. Throughout this procedure, the namespace is called demo.

      oc new-project demo

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   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

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      Note

      This YAML has been reused from Service Binding Operator Quickstart.

   3. Apply the created custom resource:

      oc apply -f ~/pg-cluster.yml

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      Note

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

   4. Check the Pods to verify the installation:

      oc get pods -n demo

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      • Wait for the Pods to get into the READY state, which signals the installation is complete.

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

   • The application we are going to create is going to be a simple todo application that will connect to PostgreSQL by using hibernate and panache.

     1. Generate the application:

        mvn com.redhat.quarkus.platform:quarkus-maven-plugin:2.13.9.SP2-redhat-00003:create \
          -DplatformGroupId=com.redhat.quarkus.platform \
          -DplatformVersion=2.13.9.SP2-redhat-00003 \
          -DprojectGroupId=org.acme \
          -DprojectArtifactId=todo-example \
          -DclassName="org.acme.TodoResource" \
          -Dpath="/todo"

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     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"

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

        package org.acme;
        
        import javax.persistence.Column;
        import javax.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;
            }
        
        }

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     4. Expose the entity:

        package org.acme;
        
        import javax.transaction.Transactional;
        import javax.ws.rs.*;
        import javax.ws.rs.core.Response;
        import javax.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();
               }
        
           }

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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 done by setting a quarkus.kubernetes-service-binding.services.<id>. prefix as in the example below. The id is used to group properties together and can be anything.

        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

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   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);

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

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

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   • Wait for the deployment to finish.

Verification

1. Verify the deployment:

   oc get pods -n demo -w

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2. Verify the installation

   1. Port forward to http port locally and access the /todo endpoint:

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

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   2. Open the following URL in a browser:

      http://localhost:8080/todo

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