Can't communicate with pods through services - laravel

Question

I have two deployment, where one of them creates 4 replica for php-fpm and another is a nginx webserver exposed to Internet through Ingress.
problem is that I can't connect to app service in webserver pod! (same issue while trying to connect to other services)
ping result:
$ ping -c4 app.ternobo-connect
PING app.ternobo-connect (10.245.240.225): 56 data bytes
--- app.ternobo-connect ping statistics ---
4 packets transmitted, 0 packets received, 100% packet loss
but pods are individually available with their ClusterIP.
app-deployment.yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
ternobo.kubernates.service: app
ternobo.kubernates.network/app-network: "true"
name: app
namespace: ternobo-connect
spec:
replicas: 4
strategy:
rollingUpdate:
maxSurge: 1
maxUnavailable: 50%
selector:
matchLabels:
ternobo.kubernates.service: app
template:
metadata:
labels:
ternobo.kubernates.network/app-network: "true"
ternobo.kubernates.service: app
spec:
containers:
- env:
- name: SERVICE_NAME
value: app
- name: SERVICE_TAGS
value: production
image: ghcr.io/ternobo/ternobo-connect:0.1.01
name: app
ports:
- containerPort: 9000
resources: {}
tty: true
workingDir: /var/www
envFrom:
- configMapRef:
name: appenvconfig
imagePullSecrets:
- name: regsecret
restartPolicy: Always
status: {}
app-service.yaml:
apiVersion: v1
kind: Service
metadata:
labels:
ternobo.kubernates.network/app-network: "true"
name: app
namespace: ternobo-connect
spec:
type: ClusterIP
ports:
- name: "9000"
port: 9000
targetPort: 9000
selector:
ternobo.kubernates.service: app
status:
loadBalancer: {}
network-policy:
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: app-network
namespace: ternobo-connect
spec:
podSelector: {}
ingress:
- {}
policyTypes:
- Ingress
I also tried to removing netwok policy and but it didn't work! and change podSelector rules to only select services with ternobo.kubernates.network/app-network: "true" label.

Answer 1

Kubernetes services urls are in my-svc.my-namespace.svc.cluster-domain.example format, see: https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/#a-aaaa-records
So the ping should be
ping -c4 app.ternobo-connect.svc.cluster.local
If the webserver is in the same namespace as the service you can ping the service name directly
ping -c4 app
I don't know the impact of network policy, I haven't worked with it.