How to find the url of a service in kubernetes? - kubernetes

Question

I have a local kubernetes cluster on my local docker desktop.
This is how my kubernetes service looks like when I do a kubectl describe service
Name: helloworldsvc
Namespace: test
Labels: app=helloworldsvc
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"app":"helloworldsvc"},"name":"helloworldsvc","namespace":"test...
Selector: app=helloworldapp
Type: ClusterIP
IP: 10.108.182.240
Port: http 9111/TCP
TargetPort: 80/TCP
Endpoints: 10.1.0.28:80
Session Affinity: None
Events: <none>
This service is pointing to a deployment with a web app.
My question how to I find the url for this service?
I already tried http://localhost:9111/ and that did not work.
I verified that the pod that this service points to is up and running.

Answer 1

URL of service is in the below format:
<service-name>.<namespace>.svc.cluster.local:<service-port>
In your case it is:
helloworldsvc.test.svc.cluster.local:9111

Answer 2

Get the service name: kubectl get service -n test
URL to a kubernetes service is service-name.namespace.svc.cluster.local:service-port where cluster.local is the kubernetes cluster name.
To get the cluster name: kubectl config get-contexts | awk {'print $2'}
URL to service in your case will be helloworldsvc.test.svc.cluster.local:9111
The way you are trying to do won't work as to make it available on your localhost you need to make the service available at nodeport or using port-forward or using kubectl proxy.
However, if you want dont want a node port and to check if inside the container everything works fine then follow these steps to get inside the container if it has a shell.
kubectl exec -it container-name -n its-namespace-name sh
then do a
curl localhost:80 or curl helloworldsvc.test.svc.cluster.local:9111 or curl 10.1.0.28:80
but both curl commands will work only inside Kubernetes pod and not on your localhost machine.
To access on your host machine kubectl port-forward svc/helloworldsvc 80:9111 -n test

Answer 3

The service you have created is of type ClusterIP which is only accessible from inside the cluster. You have two ways to access it from your desktop:
Create a nodeport type service and then access it via nodeip:nodeport
Use Kubectl port forward and then access it via localhost:forwardedport

Answer 4

The following url variations worked for me when in the same cluster and on the same namespace (namespace: default; though all but first should still work when services are on different namespaces):
http://helloworldsvc
http://helloworldsvc.default
http://helloworldsvc.default.svc
http://helloworldsvc.default.svc.cluster.local
http://helloworldsvc.default.svc.cluster.local:80
//
using HttpClient client = new();
string result = await client.GetStringAsync(url);
Notes:
I happen to be calling to and from an ASP.NET 6 application using HttpClient
That client I think just sets port to 80 by default, so no 80 port needs to be explicitly set to work. But I did verify for all of these it can be added or removed from the url
http only (not https, unless you configured it specially)
namespace can only be omitted in the first case (i.e. when domain / 'authority' is just the service name alone). So helloworldsvc.svc.cluster.local:80 fails with exception "Name or service not known (helloworldsvc.svc.cluster.local:80)"

Answer 5

If you are working with minikube , you can run the code below
minikube service --all
for specific service
minikube service service-name --url

Answer 6

Here is another way to get the URL of service
Enter one pod through kubectl exec
kubectl exec -it podName -n namespace -- /bin/sh
Then execute nslookup IP of service such as 172.20.2.213 in the pod
/ # nslookup 172.20.2.213
nslookup: can't resolve '(null)': Name does not resolve
Name: 172.20.2.213
Address 1: 172.20.2.213 172-20-2-213.servicename.namespace.svc.cluster.local
Or execute nslookup IP of serviceName in the pod
/ # nslookup servicename
nslookup: can't resolve '(null)': Name does not resolve
Name: 172.20.2.213
Address 1: 172.20.2.213 172-20-2-213.servicename.namespace.svc.cluster.local
Now the service URL is servicename.namespace.svc.cluster.local attached with the service port after removing IP for the output of nslookup.