Lab 3 - Debugging¶

30 min Intermediate

Problem¶

The Hyper Drive isn't working, and we need to find out why. Debug the hyper-drive deployment and its service so we can reach light speed again.

Some tips to get you started:

Check the status and description of the deployment and its pods.
Get the logs of one of the broken pods and save them to a file.
Check that the correct ports are used everywhere.
Make sure your labels and selectors match.
Check that the probes are working.

The application listens on port 8080 and serves its health check on /healthz.

Setup¶

Create a project, then apply the broken application:

oc new-project vader

oc apply -f - <<'EOF'
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hyper-drive
spec:
  replicas: 3
  selector:
    matchLabels:
      app: hyper-drive
  template:
    metadata:
      labels:
        app: hyper-drive
    spec:
      containers:
        - name: hyper-drive
          image: registry.k8s.io/e2e-test-images/agnhost:2.56
          args: ["netexec", "--http-port=8080"]
          ports:
            - containerPort: 8080
          livenessProbe:
            tcpSocket:
              port: 80
---
apiVersion: v1
kind: Service
metadata:
  name: hyper-drive
spec:
  selector:
    run: hyper-drive
  ports:
    - protocol: TCP
      port: 80
EOF

Wait a minute or two before you start. Some of the problems only show up after the pods have been running for a while.

Verification¶

You're done when all of the following are true:

All 3 hyper-drive pods are Running, 1/1 ready, and their RESTARTS count has stopped increasing:
```
oc get pods -l app=hyper-drive
```

The service has 3 endpoints on port 8080:

oc get endpointslices -l kubernetes.io/service-name=hyper-drive

The service answers from inside the cluster. Start a client pod, then call the service by name:

oc run client --image=registry.access.redhat.com/ubi9/ubi-minimal -- sleep infinity
oc wait --for=condition=Ready pod/client
oc exec client -- curl -s --max-time 5 hyper-drive/hostname

This prints the name of one of the hyper-drive pods.

Cleanup¶

oc delete project vader