How to explicitely define an Endpoint of an Kubernetes Service - kubernetes

Question

I've provisioned a kubernetes cluster on my own couple of virtual machines via kubespray. Kubespray uses project-calico as default network-plugin which fits my requirements of proxying services in the cluster network to the outer world pretty well.
Kubespray deploys the apiserver itself as a ClusterIP Service. To make it reachable from outside it defines an Endpoint of this service with the master nodes Host IP Adress, which is routed to the internal ClusterIP by Calico as far as I could figure it out by myself.
My Question is: How is it possible to define my own endpoint (for another service), as these get implicietly defined already by provisioning the service.yaml and cannot be overwritten. I would like to follow a similar approach to get my Rook/Ceph Dashboard visible from outside the cluster.
EDIT: Note that kubectl get ingresses.networking.k8s.io --all-namespaces returns No resources found. and kubectl describe service kubernete returns
Name: kubernetes
Namespace: default
Labels: component=apiserver
provider=kubernetes
Annotations: <none>
Selector: <none>
Type: ClusterIP
IP: 10.233.0.1
Port: https 443/TCP
TargetPort: 6443/TCP
Endpoints: 192.168.103.254:6443
Session Affinity: None
Events: <none>

Answer 1

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: v1
kind: Service
metadata:
name: my-service
spec:
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: v1
kind: Endpoints
metadata:
name: my-service
subsets:
- 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.

Answer 2

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: v1
kind: Service
metadata:
name: examplelb
spec:
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 pattern
internal port 22223 exposed on 31913.
$ kubectl get svc examplelb
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
examplelb 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.