Enabling a Kubernetes service for discovery

You can configure the IBM Multicloud Manager service registry to discover Kubernetes services that are in different IBM Multicloud Manager managed clusters.

A Kubernetes service exposes a group of pods that are running on a managed cluster. The IBM Multicloud Manager service discovery function only discovers Kubernetes services that are configured to be discovered.

Required user type or access level: Cluster administrator.

Discover the Kubernetes service

To discover a Kubernetes service on your managed clusters, complete the following steps:

1. Annotate the service to enable the service discovery.

   You must enable the service in the managed cluster to be discovered by adding the following annotation to your service definition yaml file for the service that you want to discover:

   mcm.ibm.com/service-discovery
   

   The following example shows the format for the dbservice:

   apiVersion: v1
   kind: Service
   metadata:
    annotations:
      mcm.ibm.com/service-discovery: "{}"
    name: dbservice
    namespace: database
   spec:
    type: LoadBalancer
    ports:
    - name: http
      nodePort: 8080
      port: 8000
      protocol: TCP
    selector:
      app: dbservice
   

   Note: The Kubernetes service that you want to discover must be either a LoadBalancer or NodePort type.

2. If the service that you added the discovery annotation for has other applications that depend on it, add the service to the application's entry as a deployable dependency.

   The following example shows how to add this dependency:

   apiVersion: apps.ibm.com/v1alpha1
   kind: Deployable
   metadata:
    name: name1
    namespace: workspace
   spec:
    template:
      apiVersion: extensions/v1beta1
      kind: Deployment
      metadata:
        name: ibm-websphere
        labels:
          app: ibm-websphere
      spec:
        replicas: 1
        selector:
          matchLabels:
            app: ibm-websphere
        template:
          metadata:
            labels:
              app: ibm-websphere
          spec:
            containers:
            - name: ibm-websphere
              image: "registry.ng.bluemix.net/seed/ibm-websphere-sample"
              imagePullPolicy: Always
    dependencies:
    - name: dbservice
      namespace: database
      kind: Service
      apiGroup: v1
   placement:
      clusterNames:
      - managed cluster1
   

   The deployable dependent service is automatically discovered in the cluster (managed cluster1) in which the application is deployed.

3. Access the discovered service by using the following format:

   <service-name>.<service-namespace>.<service-registry-dns-suffix>
   

An example of the format is: dbservice.database.mcm.svc.