Welcome to the Linux Foundation Forum!

Pod Networking

Hi !

I am starting to make sense of the Pod Networking model used with K8s and Calico.
I only have one outstanding question I am finding difficult to find the answer.
From everything I have read, I understand that each POD has its own network namespace and a single IP address that is provided by calico.
When deploying the nginx deployment and exposing it with ClusterIP, if I login to one of the pods that make the deployment and try to find out the internal IP, I can't.
The only part where the internal IP of the pod is found is on /etc/hosts.

  1. vxr@ubuntu-k8s-master:~$ kubectl exec nginx-7848d4b86f-7bq85 -- ip link list
  2. OCI runtime exec failed: exec failed: container_linux.go:380: starting container process caused: exec: "ip": executable file not found in $PATH: unknown
  3. command terminated with exit code 126
  4. vxr@ubuntu-k8s-master:~$
  1. vxr@ubuntu-k8s-master:~$ kubectl get ep
  2. NAME ENDPOINTS AGE
  3. kubernetes 172.19.187.10:6443 2d21h
  4. nginx 192.168.171.69:80,192.168.171.70:80,192.168.171.72:80 16h

So my question is:

1 - How can I find the internal eth0 interface from inside the pod ?
2 - How can I find the mapped IP address from inside the pod ?

Thank you very much !!!

Best Answer

  • Posts: 1,000
    Answer ✓

    Hello,

    First you would need to deploy a pod that has the necessary commands. Probably the easiest way to find the interfaces and IP addresses is to use the ip command inside a shell of a container in the pod. Other IP information can be seen via environmental, using the env command, as is seen in Exercise 3.5, step 2.

    Regards,

Answers

  • Thank you ! So I guess that the issue here is more about the Pod not having the right commands, in that case the "ip" command. I was able to find IP information looking at the /etc/hosts file but will also look at the env.
    Really appreciate your help @serewicz !

Welcome!

It looks like you're new here. Sign in or register to get started.
Sign In

Welcome!

It looks like you're new here. Sign in or register to get started.
Sign In

Categories

Upcoming Training