Scenario: "Bilbao": Basic Kubernetes Problems

Level: Easy

Type: Fix

Access: Email

Description: There's a Kubernetes Deployment with an Nginx pod and a Load Balancer declared in the manifest.yml file. The pod is not coming up. Fix it so that you can access the Nginx container through the Load Balancer.

There's no "sudo" (root) access.

Test: Running curl 10.43.216.196 returns the default Nginx Welcome page.

See /home/admin/agent/check.sh for the test that "Check My Solution" runs.

Time to Solve: 10 minutes.

Scenario: "Buenos Aires": Kubernetes Pod Crashing

Level: Medium

Type: Fix

Access: Email

Description: There are two pods: "logger" and "logshipper" living in the default namespace. Unfortunately, logshipper has an issue (crashlooping) and is forbidden to see what logger is trying to say. Could you help fix Logshipper?

Do not change the K8S definition of the logshipper pod. Use "sudo".

Because k8s takes a minute or two to change the pod state initially, the check for the scenario is made to fail in the first two minutes.

Credit Srivatsav Kondragunta

Test: kubectl get pods -l app=logshipper --no-headers -o json | jq -r '.items[] | "\(.status.containerStatuses[0].ready)"' returns true

Time to Solve: 20 minutes.

Scenario: "Poznań": Helm Chart Issue in Kubernetes

Level: Medium

Type: Fix

Access: Paid

Description: NOTE: Prompt may take a few extra seconds to be responsive while the k3s environment gets ready. Root access is not needed for this challenge ("admin" user cannot sudo).

A DevOps engineer created a Helm Chart web_chart with a custom nginx site, however he still gets the default nginx index.html.

You can check for example with POD_IP=$(kubectl get pods -n default -o jsonpath='{.items[0].status.podIP}') and curl -s "${POD_IP}">.

In addition he should set replicas to 3.

The chart is not working as expected. Fix the configurations so you get the custom HTML page from any nginx pod.

Credit Kamil Błaż

Test: Doing curl on the default port (:80) of any nginx pod returns a Welcome SadServers page. The "Check My Solution" button runs the script /home/admin/agent/check.sh, which you can see and execute.

Time to Solve: 15 minutes.

Scenario: "Bengaluru": Kubernetes StatefulSet least known characteristic

Level: Medium

Type: Fix

Access: Email

Description: There's a Kubernetes cluster (created with "k3d") with two worker nodes and two pods on the node k3d-cluster-agent-0: a Deployment demo-deployment-... and a StatefulSet demo-statefulset-0. Their manifests are identical except for the different kind of K8s resource.

Make the node hosting the pods unavailable (it "goes down" or "crashes" without being deleted from k8s), for example with: docker stop k3d-mycluster-agent-0.

After waiting for about a minute (tolerationSeconds in the manifest is 30s, we shorten the K8S 5 minutes default so you don't have to wait so much, plus a grace period), both pods are marked as Terminating. While the Deployment pod is evicted and deployed onto the remaining available node k3d-cluster-agent-1, the StatefulSet demo-statefulset-0 is not (Why?).

Make the StatefulSet pod demo-statefulset-0 run on the available node.

Note: you can use k as a shortcut for kubectl.

Test: Node k3d-cluster-agent-0 is NotReady. Both the Deployment and the StatefulSet are running on the node k3d-cluster-agent-1
The "Check My Solution" button runs the script /home/admin/agent/check.sh, which you can see and execute.

Time to Solve: 15 minutes.

Scenario: "Ruaka": Kubernetes pod in distress

Level: Medium

Type: Fix

Access: Paid

Description: A developer wants to deploy an open-source tool on Kubernetes. The tool unfortunately has limited documentation.

They built a helm chart and a container image. When the application is deployed, for some reason the server in Kubernetes doesn't seem to work but when the binary is started on their laptop/machine it works perfectly.

The application server is deployed by Helm. The command they used is: helm upgrade --install ruaka charts/ruaka.

Debug and help the developer find the issue. NOTE: Do not change or delete any current Helm field value in the chart, only add if needed.

Remember to give enough time to k8S after you apply a change before checking the solution.

Test: kubectl get pod shows the ruaka application pod up and running, while no Helm fields have been taken out from the applicaiton chart.

The "Check My Solution" button runs the script /home/admin/agent/check.sh, which you can see and execute.

Time to Solve: 15 minutes.

Scenario: "Singara": Docker and Kubernetes web app not working.

Level: Hard

Type: Fix

Access: Email

Description: There's a k3s Kubernetes install you can access with kubectl. The Kubernetes YAML manifests under /home/admin have been applied. The objective is to access from the host the "webapp" web server deployed and find what message it serves (it's a name of a town or city btw). In order to pass the check, the webapp Docker container should not be run separately outside Kubernetes as a shortcut.

Test: curl localhost:8888 returns a value from the webapp deployed Kubernetes pod.

Time to Solve: 20 minutes.

Scenario: "Amygdala": Do you have enough insight to see the secrets?

Level: Hard

Type: Fix

Access: Paid

Description: Troubleshoot and fix a Kubernetes web application running in the app namespace. Make the deployment run successfully so that it returns Hello handsome! when you curl it.

Fix first your admin user access to the local Kubernetes cluster; the KUBECONFIG environment variable must be set to $HOME/.kube/config.

You have full admin access to a Vault server (containing the secrets you need) from the admin user. All the used manifests for the application are placed on the /home/admin/manifests directory.

Test: Running: POD_IP=$(kubectl get po -n app -l app=app -o jsonpath='{.items[0].status.podIP}') curl http://$POD_IP returns Hello handsome!.

The "Check My Solution" button runs the script /home/admin/agent/check.sh, which you can see and execute.

Time to Solve: 20 minutes.