Kubernetes Tips

Use the nice starship command line prompt, which supports Kubernetes: https://starship.rs/config/#kubernetes This needs te be activated in ~/.config/starship.toml.

kubectl

Create a simple service

k create deployment mynginx --image=nginx 

k expose deployment mynginx --port 8080 --target-port 80


k port-forward services/mynginx 8080

# keep above command running and open a second shell

open http://localhost:8080

Get external IP of a control plane

kubectl get nodes -o jsonpath="{.items[*].status.addresses[?(@.type=='ExternalIP')].address}" -l node-role.kubernetes.io/control-plane |  cut -d' ' -f1

Stern

Show all logs of the last 5min by time, sorted by time

stern --since=5m --no-follow --only-log-lines -A -t . | sort -k4

By the way, I prefer to install stern via brew. I don't know why the kubectl plugin manager krew exists.

Not solved yet

How to get all pods of a deployment.

https://stackoverflow.com/questions/52957227/kubectl-command-to-list-pods-of-a-deployment-in-kubernetes

Ugly shell scripts.

Things I would like to see in core (k/k)

Things I would like in the core of Kubernetes:

• stakater/Reloader: A Kubernetes controller to watch changes in ConfigMap and Secrets and do rolling upgrades on Pods with their associated Deployment, StatefulSet, DaemonSet and DeploymentConfig.
• Kubernetes Cluster Proportional Autoscaler: Scale the amount of pods by the size of the cluster (Node/CPU count).
• postfinance/kubelet-csr-approver: Kubernetes controller to enable automatic kubelet CSR validation after a series of (configurable) security checks.