Intermediate Reading #kubernetes #k8s #yaml #devops

Reading Kubernetes Manifests

5 exercises on reading Kubernetes Deployment YAML: API versioning, resource requests and limits, liveness probes, rolling update strategies, and Secrets vs ConfigMaps.

Kubernetes manifest structure

apiVersion + kind — which API handles it and what type of resource
metadata — name, namespace, labels (used by selectors)
spec — desired state: replicas, containers, volumes, strategy
resources.requests — minimum guaranteed (used for scheduling)
resources.limits — maximum allowed (CPU: throttle; memory: OOMKill)
livenessProbe → restart if unhealthy; readinessProbe → stop traffic if not ready

0 / 5 completed

1 / 5

Read this Kubernetes Deployment manifest excerpt and answer the question:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: api-server
  namespace: production
spec:
  replicas: 3
  selector:
    matchLabels:
      app: api-server

What do apiVersion: apps/v1 and kind: Deployment tell Kubernetes?

2 / 5

Read this container spec and answer the question:

    spec:
      containers:
        - name: api-server
          image: myregistry.io/api-server:2.4.1
          resources:
            requests:
              memory: "256Mi"
              cpu: "250m"
            limits:
              memory: "512Mi"
              cpu: "500m"

What happens if the container's CPU usage consistently reaches 500m (the limit)?

3 / 5

Read this liveness probe configuration and answer the question:

          livenessProbe:
            httpGet:
              path: /healthz
              port: 8080
            initialDelaySeconds: 15
            periodSeconds: 10
            failureThreshold: 3

What action does Kubernetes take when the liveness probe fails 3 times in a row?

4 / 5

Read this Deployment update strategy and answer the question:

  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0

What does maxUnavailable: 0 guarantee during a rolling update?

5 / 5

Read this environment injection and answer the question:

          env:
            - name: DB_HOST
              valueFrom:
                secretKeyRef:
                  name: db-credentials
                  key: host
            - name: LOG_LEVEL
              valueFrom:
                configMapKeyRef:
                  name: app-config
                  key: log_level

What is the key difference between a Kubernetes Secret and a ConfigMap?