example.yaml

apiVersion: v1
kind: Pod
metadata:
  name: runner
  namespace: tmp
spec:
  terminationGracePeriodSeconds: 60
  volumes:
    - name: share
      emptyDir: {}
  containers:
  - name: sidecar
    command: ["python", "-c", "import time;time.sleep(9999)"]
    image: python:3.5
    lifecycle:
      preStop:
        exec:
          command: ["sh", "-c", "while ! [ -f /tmp/share/kill_sidecar ]; do sleep 1; done; kill -2 1"]
    volumeMounts:
      - mountPath: /tmp/share
        name: share
  - command:
    - sh
    - -c
    - >
      touch /tmp/messaging &&
      while ! [ -f /tmp/kill_me ];
        do
        cat /tmp/messaging;
        rm /tmp/messaging && touch /tmp/messaging;
        sleep 1;
      done;
      touch /tmp/share/kill_sidecar
    image: bash
    name: runner
    lifecycle:
      postStart:
        exec:
          command: ["sh", "-c", "echo postStart >> /tmp/messaging"]
      preStop:
        exec:
          command: ["sh", "-c", "echo preStop >> /tmp/messaging && sleep 10 && touch /tmp/kill_me"]
    volumeMounts:
      - mountPath: /tmp/share
        name: share