Challenge 04 - Your First Deployment - Coach’s Guide

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Notes & Guidance

• Students will be provided with two sample template yaml files one for a Service resource and one for a Deployment resource. A good recommendation would be to create two copies of each (one set for content-api and one set for content-web)
• Students will need to find extra settings to add to their template YAML files. They should make use of the Kubernetes docs in addition to whatever else they can find on the web.
  • NOTE: Fully fleshed out YAML files are available in the Coach Solutions folder for Challenge 4.
  • NOTE: If you observe students using foo and bar unchanged in the template files, you should recommend they consider more relevant names such as web, content-web, api, or content-api.
• In the Deployment YAML for content-api, they’ll need these settings in the spec section:
  • containers.resources.requests.cpu: 0.5 (or 500m)
  • containers.resources.requests.memory: 128Mi
  • containers.ports.containerPort: 3001
• In the deployment YAML for content-web, they will need these settings in the spec section:
  • containers.resources.requests.cpu: 0.5 (or 500m)
  • containers.resources.requests.memory: 128Mi
  • containers.ports.containerPort: 3000
  • containers.env.name: CONTENT_API_URL
  • containers.env.value: http://content-api:3001
    • NOTE: The value content-api in the URL must be whatever was used as the name of the service during deployment.
• In the Service YAML for content-web, they need to figure out that the type should be changed to “LoadBalancer”.
• Coaches should be familiar with common kubectl commands in order to help the students troublshoot:
  • kubectl get nodes
  • kubectl get pods
  • kubectl describe pod <pod-name>
  • kubectl get services
  • kubectl get deployments
  • kubectl delete deployment <deployment-name>
  • kubectl delete pod <pod-name>
    • kubectl delete service <service-name>
  • kubectl apply -f <yaml-file>
• Running a shell in a pod:
  • If students get stuck, point them to: https://kubernetes.io/docs/tasks/debug-application-cluster/get-shell-running-container/
  • Additionally, you may want to coach the students that a number of tools make this as easy as point and click. Encourage your students to try out any of VS Code with the AKS Extension, Lens, or K9S
• When the service is deployed it will take some time for an External IP to be assigned.
  • Issue the following kubectl command and look in the EXTERNAL-IP column
    • kubectl get services
  • You will see <pending> if the IP hasn’t yet been assigned.
• To verify that the API app is correctly deployed the students need to:
  • Figure out the name of the pod the API app was deployed to, eg: - content-api-23aceed
  • Then use a kubectl command like this to get a bash shell:
    • kubectl exec -it content-api-23aceed -- /bin/bash
  • To verify the API app is working you need to curl the /speakers endpoint:
    • curl http://localhost:3001/speakers
  • They should see a huge JSON document printed to the screen.

Videos

Challenge 4 Solution