anchor.diff:      spec:
         containers:
           - name: member
  -          image: centos/mongodb-26-centos7
  +          image: openshift/mongodb-24-centos7
             env:
               - name: MONGODB_USER
                 value: "${MONGODB_USER}"
  
positive.code: === Creating the Service Pod
  
  To initialize members created by xref:creating-the-deploymentconfig[the
  deployment configuration], a _service pod_ is defined in the template. This pod
  starts MongoDB with the `initiate` argument, which instructs the container
  entrypoint to behave xref:mongo-creating-headless-service[slightly differently]
  than a regular, stand-alone MongoDB database.
  
  [[example-service-pod]]
  .Service Pod Object Definition in the Example Template
  ====
  
  [source,yaml]
  ----
  kind: "Pod"
  apiVersion: "v1"
  metadata:
    name: "mongodb-service"
    creationTimestamp: null
    labels:
      name: "mongodb-service"
  spec:
    restartPolicy: "Never"
    dnsPolicy: "ClusterFirst"
    containers:
      - name: "initiate"
        image: "centos/mongodb-26-centos7"
        args:
          - "initiate"
        env:
          - name: "MONGODB_USER"
            value: "${MONGODB_USER}"
          - name: "MONGODB_PASSWORD"
            value: "${MONGODB_PASSWORD}"
          - name: "MONGODB_DATABASE"
            value: "${MONGODB_DATABASE}"
          - name: "MONGODB_ADMIN_PASSWORD"
            value: "${MONGODB_ADMIN_PASSWORD}"
          - name: "MONGODB_REPLICA_NAME"
            value: "${MONGODB_REPLICA_NAME}"
          - name: "MONGODB_SERVICE_NAME"
            value: "${MONGODB_SERVICE_NAME}"
          - name: "MONGODB_KEYFILE_VALUE"
            value: "${MONGODB_KEYFILE_VALUE}"
  ----
  ====
  
  [[mongo-creating-headless-service]]
  === Creating a Headless Service
  
  The `initiate` argument in the xref:example-service-pod[container specification
  above] instructs the container to first discover all running member pods within
  the MongoDB cluster. To achieve this, a _headless service_ is defined named
  *mongodb* in the example template.
  
negative.code: member of the cluster.
  
  Once the *PRIMARY* member has been elected, the entrypoint script starts
  creating MongoDB users and databases.
  
  Clients can then start using the MongoDB instance by sending the queries to the
  *mongodb* service. As this service is a headless service, they do not need to
  