Kubernetes

Notes relating to Kubernetes!

Kubernetes

Tools

Kind

kubectx/kubens

Super useful for easily switching contexts and namespaces

Stern

Great for live tailing logs from multiple pods/containers

kube-ps1

Shows some nice Kubernetes output in the CLI

keda

chart-testing

The ct command is great for testing Helm charts

Commands

Get pods

kubectl get po

Create Service Account

ClusterRoleBinding

Rollout Restart

kubectl rollout restart -n $namespace deployment/$deployment-name

Running a one-off command against a pod

The below runs env within the pod without having the directly exec into it

kubectl exec -it my-pod-name -- env

Tail logs

Use stern for this!

Init Containers

To view logs from the init container, use the -c flag

kubectl logs <pod-name> -c <init-container>

Resources

External Secrets

Used to create Secret resources without needing to store credentials in source control!

AWS system manager (Parameter )

Basic Setup

apiVersion: "kubernetes-client.io/v1"
kind: ExternalSecret
metadata:
  name: hello-service
spec:
  backendType: systemManager
  data:
    - name: password
      key: /hello-service/password

Namespaces

Deleting namespaces

Namespaces can often get stuck in a Terminating process despite being completely empty

To fully delete the namespace, run the following

NAMESPACE=linkerd
kubectl get namespace $NAMESPACE -o json > $NAMESPACE.json
sed -i -e 's/"kubernetes"//' $NAMESPACE.json
kubectl replace --raw "/api/v1/namespaces/$NAMESPACE/finalize" -f ./$NAMESPACE.json