From Pod to localhost, ssh works well. And ping also works well with each other. There is centos7 in Pod. Also, openssh-server is installed in Pod. But there is always an error.
kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE
hadoop-master-pod 1/1 Running 0 39m 10.244.9.25 slave10 <none>
hadoop-secondary-pod 1/1 Running 0 48m 10.244.11.11 slave12 <none>ssh 10.244.9.25
ssh: connect to host 10.244.9.25 port 22: Connection refused10.244.9.25 IP is an internal IP address given to pod by Kubernetes ( you can read more about Kubernetes networking model here ) to use inside Kubernets cluster so you won't be able to SSH or even to ping to these IPs from outside the cluster. In other words the network containing 10.244.9.25 is like a private network inside the K8 cluster and your host machine (localhost) is on different network.
If you want to get into the container for example in here you can use kubectl exec -it hadoop-master-pod -- /bin/bash or /bin/sh depending on the shell installed in the container and you can do anything that you tried to do by SSH into the pod.
If you really want to SSH into the pod from localhost (outside the cluster) you can write a Kubernetes Service probably exposing over NodePort which will expose the 22 (default port of SSH) to outside via NodePort.
You should be able to connect using kubectl exec -it hadoop-master-pod -- /bin/bash
Then You can check if your pod in listening on port 22 for 0.0.0.0
Check the iptables if there is nothing blocked.
Make sure openssh is running and on which port it's running.