How do I check if a Kubernetes pod was killed for OOM or DEADLINE EXCEEDED?

If the pods are still showing up when you type kubectl get pods -a then you get type the following kubectl describe pod PODNAME and look at the reason for termination. The output will look similar to the following (I have extracted parts of the output that are relevant to this discussion):

Containers:
  somename:
    Container ID: docker://5f0d9e4c8e0510189f5f209cb09de27b7b114032cc94db0130a9edca59560c11
    Image:      ubuntu:latest
    ...
    State:      Terminated
      Reason:       Completed
      Exit Code:    0

In the sample output you will, my pod's terminated reason is Completed but you will see other reasons such as OOMKilled and others over there.

If the pod has already been deleted, you can also check kubernetes events and see what's going on:

$ kubectl get events

LAST SEEN   FIRST SEEN   COUNT    NAME                                               KIND                      SUBOBJECT                                     TYPE      REASON                SOURCE    MESSAGE
59m         59m          1        my-pod-7477dc76c5-p49k4                            Pod                       spec.containers{my-service}                   Normal    Killing               kubelet   Killing container with id docker://my-service:Need to kill Pod