doc: Update Kubernetes examples to use Readiness Checks (#8727)

docs/orchestration/kubernetes/minio-distributed-headless-service.yaml

@@ -5,6 +5,7 @@ metadata:
   labels:
     app: minio
 spec:
+  publishNotReadyAddresses: true
   clusterIP: None
   ports:
     - port: 9000

docs/orchestration/kubernetes/minio-distributed-statefulset.yaml

@@ -5,6 +5,7 @@ metadata:
   name: minio
 spec:
   serviceName: minio
+  podManagementPolicy: Parallel
   replicas: 4
   selector:
     matchLabels:
@@ -41,6 +42,15 @@ spec:
             port: 9000
           initialDelaySeconds: 120
           periodSeconds: 20
+        # Readiness probe detects situations where MinIO server instance
+        # is not ready to accept connections. Kubernetes automatically
+        # stops all the traffic to the pods if readiness checks fail.
+        readinessProbe:
+          httpGet:
+            path: /minio/health/ready
+            port: 9000
+          initialDelaySeconds: 120
+          periodSeconds: 20
   # These are converted to volume claims by the controller
   # and mounted at the paths mentioned above.
   volumeClaimTemplates: