Pods do not resolve the domain names of a service through ingress - dns

Question

I have a problem that my pods in minikube cluster are not able to see the service through the domain name.
to run my minikube i use the following commands (running on windows 10):
minikube start --vm-driver hyperv;
minikube addons enable kube-dns;
minikube addons enable ingress;
This is my deployment.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
run: hello-world
name: hello-world
namespace: default
spec:
progressDeadlineSeconds: 600
replicas: 1
revisionHistoryLimit: 10
selector:
matchLabels:
run: hello-world
strategy:
rollingUpdate:
maxSurge: 1
maxUnavailable: 1
type: RollingUpdate
template:
metadata:
creationTimestamp: null
labels:
run: hello-world
spec:
containers:
- image: karthequian/helloworld:latest
imagePullPolicy: Always
name: hello-world
ports:
- containerPort: 80
protocol: TCP
resources: {}
dnsPolicy: ClusterFirst
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
terminationGracePeriodSeconds: 30
this is the service.yaml:
apiVersion: v1
kind: Service
metadata:
labels:
run: hello-world
name: hello-world
namespace: default
selfLink: /api/v1/namespaces/default/services/hello-world
spec:
ports:
- nodePort: 31595
port: 80
protocol: TCP
targetPort: 80
selector:
run: hello-world
sessionAffinity: None
type: ExternalName
externalName: minikube.local.com
status:
loadBalancer: {}
this is my ingress.yaml:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: minikube-local-ingress
spec:
rules:
- host: minikube.local.com
http:
paths:
- path: /
backend:
serviceName: hello-world
servicePort: 80
So, if i go inside the hello-world pod and from /bin/bash will run curl minikube.local.com or nslookup minikube.local.com.
So how can i make sure that the pods can resolve the DNS name of the service?
I know i can specify hostAlias in the deployment definition, but is there an automatic way tht will allow to update the DNS of kubernetes?

Answer 1

So, you want to expose your app on Minikube? I've just tried it using the default ClusterIP service type (essentially, removing the ExternalName stuff you had) and with this YAML file I can see your service on https://192.168.99.100 where the Ingress controller lives:
The service now looks like so:
apiVersion: v1
kind: Service
metadata:
labels:
run: hello-world
name: hello-world
spec:
ports:
- port: 80
targetPort: 80
selector:
run: hello-world
And the ingress is:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: minikube-local-ingress
annotations:
ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- host:
http:
paths:
- path: /
backend:
serviceName: hello-world
servicePort: 80
Note: Within the cluster your service is now available via hello-world.default (that's the DNS name assigned by Kubernetes within the cluster) and from the outside you'd need to map, say hello-world.local to 192.168.99.100 in your /etc/hosts file on your host machine.
Alternatively, if you change the Ingress resource to - host: hello-world.local then you can (from the host) reach your service using this FQDN like so: curl -H "Host: hello-world.local" 192.168.99.100.