Call to Kubernetes service failed - kubernetes

Question

kubernetes version: 1.5.2
os: centos 7
etcd version: 3.4.0
First, I create an etcd pod, the etcd dockerfile and etcd pod YAML file like this:
etcd dockerfile:
FROM alpine
COPY . /usr/bin
WORKDIR /usr/bin
CMD etcd --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://0.0.0.0:2379
EXPOSE 2379
pod yaml file
apiVersion: v1
kind: Pod
metadata:
name: etcd
namespace: storageplatform
labels:
app: etcd
spec:
containers:
- name: etcd
image: "karldoenitz/etcd:3.4.0"
ports:
- containerPort: 2379
hostPort: 12379
After created the docker image and push to dockerhub, I run the command kubectl apply -f etcd.yaml to create the etcd pod.
The ip of etcd pod is 10.254.140.117, I ran the command use ETCDCTL_API=3 etcdctl --endpoints=175.24.47.64:12379 put 1 1 and got OK.
My service yaml:
apiVersion: v1
kind: Service
metadata:
name: storageservice
namespace: storageplatform
spec:
type: NodePort
ports:
- port: 12379
targetPort: 12379
nodePort: 32379
selector:
app: etcd
apply the yaml file to create the service.run the command kubectl get services -n storageplatform, I got these infomation.
NAMESPACE NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
storageplatform storageservice 10.254.140.117 <nodes> 12379:32379/TCP 51s
After all, I run the command
ETCDCTL_API=3 etcdctl --endpoints=10.254.140.117:32379 get 1
or
ETCDCTL_API=3 etcdctl --endpoints={host-ip}:32379 get 1
I got Error: context deadline exceeded.
What's the matter? How to make the service useful?

Answer 1

You defined a service that is available inside the kubernetes network using the service name/ip (10.254.140.117 ) and the service port (12379) and which is available on ALL nodes of the kubernetes cluster even outside the kubernetes network with the node port (32379)
You need to fix the service in order to map to the correct container port: targetPort must match the pod containerPort (and the port in the dockerfile).
If the error Error: context deadline exceeded persits, it hints at a communication problem. This can be explained when using the internal service ip with the external node port (your first get 1). For the node port (your second command) I assume that either the etcd pod is not running properly, or the port is firewalled on the node.

Answer 2

Change the service to refer to containerPort instead of hostPort
apiVersion: v1
kind: Service
metadata:
name: storageservice
namespace: storageplatform
spec:
type: NodePort
ports:
- port: 2379
targetPort: 2379
nodePort: 32379
selector:
app: etcd