How do you get the Node IP from inside a Pod?

The accepted answer didn't work for me, it seems fieldPath is required now:

  env:
    - name: NODE_IP
      valueFrom:
        fieldRef:
          fieldPath: status.hostIP

Is there a way to capture the Node IP from within the Pod?

Yes, easily, using the env: valueFrom: fieldRef: status.hostIP; the whole(?) list is presented in the envVarSource docs, I guess because objectFieldSelector can appear in multiple contexts.

so:

containers:
- env:
  - name: NODE_IP
    valueFrom:
      fieldRef:
         status.hostIP