If you are not familiar with the oc command, refer to OpenShift - Getting Started with the oc command.

A node contains one or more pods, and each pod contains one or more containers.

The oc exec command can be used to execute a command in a pod. The oc get pods command can be used to list the pods in the currently selected namespace.

~]# oc get pods
NAME            READY   STATUS     RESTARTS  AGE
my-pod-7stht    1/1     Running    0         8d
my-pod-ab56h    1/1     Running    0         8d
my-pod-pxzd7    1/1     Running    0         8d

In this example, the df (disk filesystem usage) command is used to list the mounted file systems usage.

~]# oc exec pod/my-pod-7stht -- df
Filesystem                           1K-blocks     Used Available Use% Mounted on
/dev/sda1                               372607   170989    177862  50% /boot
/dev/sda2                               129774     6994    122780   6% /opt

The -it flag can be used to get an interactive shell into the container.

oc exec -it pod/my-pod-7stht -- /bin/bash

You will probably need to include /bin/bash -c if you are going to be issuing a for loop in the container.

oc exec -it pod/my-pod-7stht -- /bin/bash -c 'for file in $(find -type f /usr); do echo $file; done;'