DevOps: What is Kubernetes Pod Lifecycle and Hooks?

1apiVersion: apps/v1
2kind: Deployment
3metadata:
4  name: myapp
5spec:
6  replicas: 2
7  template:
8    spec:
9      containers:
10      - name: app
11        image: myapp:latest
12        lifecycle:
13          postStart:
14            exec:
15              command:
16              - sh
17              - -c
18              - |
19                echo "Container started" > /tmp/startup.log
20                wget -qO- http://config-server/config > /app/config
21          preStop:
22            httpGet:
23              path: /shutdown
24              port: 8080
25              httpHeaders:
26              - name: X-Custom-Header
27                value: shutdown
28            exec:
29              command:
30              - sh
31              - -c
32              - sleep 15 && kill -TERM 1
33        startupProbe:
34          httpGet:
35            path: /healthz
36            port: 8080
37          failureThreshold: 30
38          periodSeconds: 10
39        readinessProbe:
40          httpGet:
41            path: /ready
42            port: 8080
43          initialDelaySeconds: 5
44          periodSeconds: 10
45        livenessProbe:
46          httpGet:
47            path: /healthz
48            port: 8080
49          initialDelaySeconds: 15
50          periodSeconds: 20