learning-kubernetes

Repo for learning how to use Kubernetes and Helm charts with the help of Kubernetes in Action book.

1. Create GKE project
2. gcloud auth login
3. gcloud config set project <GCP PROJECT ID>
4. Run gcloud auth configure-docker
5. Run refresh.sh to update docker image to google docker repository
6. Connect kubectl to your cluster w/ gcloud container
7. kubectl create serviceaccount --namespace kube-system tiller
8. kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller
9. helm init --service-account tiller
10. Install with helm install --name test -f secrets.yml node-app-helm

Try db connection:

1. Get pods kubectl get po -o wide
2. kubectl port-forward <pod id> 8888:8888
3. From another shell run curl localhost:8888

Commands

• After changes upgrade with helm upgrade test -f secrets.yml ./node-app-helm
• Run tests with helm test --cleanup test
• Delete chart with helm delete test --purge
• See why pod initialization fails kubectl describe po <pod id>
• List pods kubectl get po

Tests

Test node network failure

1. Get a list of your nodes gcloud compute instances list
2. ssh to a kube node gcloud compute ssh <node name>
3. ifconfig eth0 down
4. gcloud compute instances reset <node>

Notes

• Templating doesn't work inside values.yml files. Maybe in helm 3.
• Subchart config overrides are done by using the chart name from the yaml file, not the folder name.
• Disruptions https://kubernetes.io/docs/concepts/workloads/pods/disruptions/#voluntary-and-involuntary-disruptions
• Resource handling on nodes https://kubernetes.io/docs/tasks/administer-cluster/out-of-resource/