How to explicitely define an Endpoint of an Kubernetes Service

I am not exactly sure if what You mean but i think what You are looking for is ability to expose services externally.

You can expose Your services like Rook/Ceph Dashboard with "Publishing Services" (service types that expose internal services externally).

As quoted from kubernetes documentation:

For some parts of your application (for example, frontends) you may want to expose a Service onto an external IP address, that’s outside of your cluster.

Kubernetes ServiceTypes allow you to specify what kind of Service you want. The default is ClusterIP.

Type values and their behaviors are:

• ClusterIP: Exposes the Service on a cluster-internal IP. Choosing this value makes the Service only reachable from within the cluster. This is the default ServiceType.
• NodePort: Exposes the Service on each Node’s IP at a static port (the NodePort). A ClusterIP Service, to which the NodePort Service routes, is automatically created. You’ll be able to contact the NodePort Service, from outside the cluster, by requesting <NodeIP>:<NodePort>.
• LoadBalancer: Exposes the Service externally using a cloud provider’s load balancer. NodePort and ClusterIP Services, to which the external load balancer routes, are automatically created.
• ExternalName: Maps the Service to the contents of the externalName field (e.g. foo.bar.example.com), by returning a CNAME record with its value. No proxying of any kind is set up.

Here is an example from documentation.

You can also define the Services with yaml manifests like this:

apiVersion: v1kind: Servicemetadata:  name: examplelbspec:  type: LoadBalancer  selector:    app: asd  ports:    -      name: koala      port: 22223      targetPort: 22225      nodePort: 31913    -      name: grisly      port: 22224      targetPort: 22226      nodePort: 31914    -      name: polar      port: 22225      targetPort: 22227      nodePort: 31915

This makes pods with label: app: asd have following ports exposed with patterninternal port 22223 exposed on 31913.

$ kubectl get svc examplelbNAME        TYPE           CLUSTER-IP     EXTERNAL-IP   PORT(S)                                           AGEexamplelb   LoadBalancer   10.111.8.204   <pending>     22223:31913/TCP,22224:31914/TCP,22225:31915/TCP   7d2h

If service with type LoadBalancer has External-IP pending you can still access all those ports on each node as NodePort.

Hope this helps.

I'll refer to your question:

How is it possible to define my own endpoint?

You'll have to:

1 ) Create a Service without a Pod selector:

apiVersion: v1kind: Servicemetadata:  name: my-servicespec:  ports:    - protocol: TCP      port: 8080      targetPort: 9376

(At this point, no auto-generated Endpoints will be created by K8S because it can't decide to which pods those Endpoints should be referring).

2 ) Crate an Endpoints object and map it to the desired network address and port where the external resource is running:

apiVersion: v1kind: Endpointsmetadata:  name: my-servicesubsets:  - addresses:      - ip: 192.0.2.45    ports:      - port: 9376

(*) Notice that there should be a match between the service name and the name of the Endpoints object.