lifecycle.yaml

apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name:  lifecycle
  labels:
    name:  helloworld
spec:
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      labels:
        app:  lifecycle
    spec:
      initContainers: # here this container will run right in the beginning before the main container
      # starts
        - name: init
          image: busybox
          command: ['sh', '-c', 'sleep 10'] # here the command is only for sleeping for 10 seconds
      containers:
      - image:  busybox
        name:  lifecyle-container
        command: ['sh', '-c', 'echo $(date +%s): Running >> /timing && echo "The app is running!" && /bin/sleep 120'] # all the commands being executed are essentially for the purpose of observing
        # the pod lifecycle
        resources:
          requests:
            cpu: "20m"
            memory: "55M"
        livenessProbe:
          exec:
            command: ['sh', '-c', 'echo $(date +%s): livenessProbe >> /timing']
          initialDelaySeconds: 35
          timeoutSeconds: 30
        readinessProbe:
          exec:
            command: ['sh', '-c', 'echo $(date +%s): readinessProbe >> /timing']
          initialDelaySeconds: 35
          timeoutSeconds: 10
        lifecycle:
          postStart:
            exec:
              command: ['sh', '-c', 'echo $(date +%s): postStart >> /timing && sleep 10 && echo $(date +%s): end postStart >> /timing']
          preStop:
            exec:
              command: ['sh', '-c', 'echo $(date +%s): preStop >> /timing && sleep 10']
        env:
        - name:  ENVVARNAME
          value:  ENVVARVALUE       
        ports:
        - containerPort:  5000
          name:  my-name
        volumeMounts:
        - mountPath: /data
          name: data
      volumes:
        - name: data
          emptyDir: {}
      restartPolicy: Always
      imagePullPolicy: Always