Probes

Image jakousa/dwk-app8:v1 works, jakousa/dwk-app8:v2 does not work. Let's try probes and rollbacks.

whoami/flaky.yml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: flaky
  namespace: __NAME__
spec:
  replicas: 3
  selector:
    matchLabels:
      app: flaky-update
  template:
    metadata:
      labels:
        app: flaky-update
    spec:
      containers:
        - name: flaky-update
          image: jakousa/dwk-app8:v1
          readinessProbe: # Should application receive traffic?
            initialDelaySeconds: 10 # Initial delay until the readiness is tested
            periodSeconds: 5 # How often to test
            httpGet:
              path: /healthz
              port: 3541
          livenessProbe: # Should application be restarted?
            initialDelaySeconds: 20 # Initial delay until the liveness is tested
            periodSeconds: 5 # How often to test
            httpGet:
              path: /healthz
              port: 3541

Apply, change image tag to v2 and see how it fails.

Fix with

kubectl rollout -n __NAME__ undo deployment/flaky

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