Im using microservice in kubernete and docker and I got an UnknownHostException
when Zuul (gateway) forward request data to service I can't ping to service container by pod name (but when i use docker swarm instead of Kubernetes, i can ping by host name normally)
This is my service yaml file
apiVersion: apps/v1beta1
kind: Deployment
metadata:
name: merchantservice
labels:
run: merchantservice
spec:
template:
metadata:
labels:
name: merchantservice
spec:
containers:
- name: merchantservice
image: merchantservice:latest
ports:
- containerPort: 8001
env:
- name: EUREKA_SERVER
value: "eureka1"
- name: EUREKA_SERVER2
value: "eureka2"
- name: CONFIG_SERVER
value: "configserver"
---
apiVersion: v1
kind: Service
metadata:
name: merchantservice
spec:
selector:
name: merchantservice
ports:
- port: 8001
targetPort: 8001
type: LoadBalancer
And this is error output
2019-05-28 04:29:53.443 WARN 1 --- [nio-8444-exec-6] o.s.c.n.z.filters.post.SendErrorFilter : Error during filtering
com.netflix.zuul.exception.ZuulException: Forwarding error
...
Caused by: com.netflix.client.ClientException: null
...
Caused by: java.lang.RuntimeException: java.net.UnknownHostException: merchantservice-79cc77d9cc-224mf: Try again
at rx.exceptions.Exceptions.propagate(Exceptions.java:57) ~[rxjava-1.3.8.jar!/:1.3.8]
at rx.observables.BlockingObservable.blockForSingle(BlockingObservable.java:463) ~[rxjava-1.3.8.jar!/:1.3.8]
at rx.observables.BlockingObservable.single(BlockingObservable.java:340) ~[rxjava-1.3.8.jar!/:1.3.8]
at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:112) ~[ribbon-loadbalancer-2.3.0.jar!/:2.3.0]
... 158 common frames omitted
Caused by: java.net.UnknownHostException: merchantservice-79cc77d9cc-224mf: Try again
...
in openshift you cannot hit a pod by pod-id but you can hit it by local DNS and service. ..svc.cluster.local: I think the same will work in your case. please try below
merchantservice.<bob-id/project-id>.svc.cluster.local:8081
I am posting @Matthew L Daniel answer from the comments for better visibility:
kube-dns does not create DNS records for pods, since they are ephemeral; if you want to address pods, use their IP or use a Service – Matthew L Daniel
Make sure that you have added eureka.instance.preferIpAddress = true in your application.properties file of the microservice which has to be routed via zuul.