I have created a service(grpc-service) on my Kubernetes cluster(ubuntu 16.04) and cannot find it's dns Hostname
Also as a side node , my pod does not show up on nslookup (it works with busybox)
kubectl exec -ti server-pod -- nslookup kubernetes.default
OCI runtime exec failed: exec failed: container_linux.go:345: starting container process caused "exec: \"nslookup\": executable file not found in $PATH": unknownexpecting somthing similar to:
grpc-service.<namespace>.svc.<cluster-domain> which is usually
grpc-service.default.svc.cluster.localbut cannot find it ,neither can ping/curl it (curl -I grpc-service)
@Tanmay Shrivastava
clusterIP: None
However, you can use headless service, use statefulset
apiVersion: v1
kind: Service
metadata:
name: httpd-service
labels:
app: httpd
spec:
ports:
- port: 80
name: web
clusterIP: None
selector:
app: httpdCheck this link: https://supergiant.io/blog/creating-stateful-apps-with-kubernetes-statefulsets/
Take below as an example. Make sure you use correct labels/selectors. And use busybox version <= busybox:1.28.4 for tests. With newer version dns doesnt work correctly.
apiVersion: v1
kind: Pod
metadata:
name: busybox-pod
labels:
app: busybox
spec:
containers:
- image: busybox:1.28.4
command:
- sleep
- "3600"
imagePullPolicy: IfNotPresent
name: busybox
restartPolicy: Always
---
apiVersion: v1
kind: Pod
metadata:
name: nginx-pod
labels:
app: nginx
spec:
hostNetwork: true
containers:
- name: client-pod
image: nginx
---
apiVersion: v1
kind: Service
metadata:
name: server
labels:
app: nginx
spec:
clusterIP: None
ports:
- port: 80
targetPort: 80
protocol: TCP
selector:
app: nginx
---Checking:
kubectl get all -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod/busybox-pod 1/1 Running 0 5m6s 10.44.2.6 gke-standard-cluster-1-default-pool-00736803-xn08 <none> <none>
pod/nginx-pod 1/1 Running 0 5m6s 10.164.0.16 gke-standard-cluster-1-default-pool-00736803-xn08 <none> <none>
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
service/kubernetes ClusterIP 10.110.0.1 <none> 443/TCP 71m <none>
service/server ClusterIP None <none> 80/TCP 5m7s app=nginx
kubectl describe service server
Name: server
Namespace: default
Labels: app=nginx
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"app":"nginx"},"name":"server","namespace":"default"},"spec":{"...
Selector: app=nginx
Type: ClusterIP
IP: None
Port: <unset> 80/TCP
TargetPort: 80/TCP
Endpoints: 10.164.0.16:80
Session Affinity: None
Events: <none>
kubectl -n default exec -ti busybox-pod -- nslookup kubernetes.default
Server: 10.110.0.10
Address 1: 10.110.0.10 kube-dns.kube-system.svc.cluster.local
Name: kubernetes.default
Address 1: 10.110.0.1 kubernetes.default.svc.cluster.local
kubectl -n default exec -ti busybox-pod -- ping server
PING server (10.164.0.16): 56 data bytes
64 bytes from 10.164.0.16: seq=0 ttl=64 time=0.089 ms
64 bytes from 10.164.0.16: seq=1 ttl=64 time=0.129 ms
64 bytes from 10.164.0.16: seq=2 ttl=64 time=0.156 ms
64 bytes from 10.164.0.16: seq=3 ttl=64 time=0.124 ms
kubectl -n default exec -ti busybox-pod -- cat /etc/resolv.conf
nameserver 10.110.0.10
search default.svc.cluster.local svc.cluster.local cluster.local
options ndots:5