WILT: Kubernetes
Looking into Kubernetes, some initial command preservation
Kubernetes, being able to orchestrate full deployments w' scaling etc. using YAML files - I remain a proponent of infrastructure-as-code in a human readable and version controllable fashion.
You need a kubectl command line tool to interact with kubernetes, and minikube is what I'm using to run local kubernetes. Grab them from Kubernetes Documentation / Tasks / Install tools.
My Wordpress Kube thing that runs on M1 (see below) is zipped and downloadable. It's based on the stateful example at Kubernetes.io Wordpress deploy example
Online references
| Name | URL | Good for |
|---|---|---|
| Kubernetes Documentation | https://kubernetes.io | Really good at getting started. Nice collection of usable commands |
| bitnami/charts | bitnami/charts/wordpress | Kubernetes document recommends using this via helm to run a production ready Wordpress. To review |
| Package manager for Helm | Helm Docs | ...managing your deployed packages |
Commands
| Command | Used for | Example |
|---|---|---|
minikube start |
Starting your local cluster | |
kubectl version |
Checking version of client and server - good to verify the server's running | |
kubectl get |
Get information on things | kubectl get nodes - Show all nodes in the cluster |
kubectl create deployment |
Create a deployment | kubectl create deployment kubernetes-bootcamp --image=gcr.io/google-samples/kubernetes-bootcamp:v1 - Deploy the Google sample application |
kubectl describe |
Get details on primitives | kubectl describe pods - Get pod information |
kubectl logs |
Get logs for a pod | kubectl logs $POD_NAME - Get the logs for pod $POD_NAME |
kubectl expose |
Open ports that will direct traffic to services | kubectl expose deployment/kubernetes-bootcamp --type="NodePort" --port 8080 - Expose a port 8080 for the kube, but we need to tie in the external port you can get it from! |
kubectrl exec |
Running stuff in the container from outside | kubectl exec --stdin --tty <container> -- /bin/bash - Get an interactive shell on the container |
helm |
Automates a bunch of Kubernetes things, using Chart and Value files, among others | See the Bitnami online reference above for a functioning use |
Gotchas
M1
Mac's M1 ARM64 architecture gives Docker conniptions. Since my training repos are from Docker images, naturally things went to hell - out of the box tutorials using MySQL failed. Some searching found someone hosting arm64 compiled MySQL architectures so I could use those. Thanks, Jamiel Sharief.
Ports
You need to use expose to get an internal port assigned a kube port; then you can use that kube port to connect:
1kubectl expose deployment/[thing] --type="NodePort" --port 8080
2export NODE_PORT=$(kubectl get services/[service-name] -o go-template='{{(index .spec.ports 0).nodePort}}')
3curl $(minikube ip):$NODE_PORT