kubectl

see also kubernetes. kubectl is the utility to control and manage kubernetes.

copy files from and to pod

copy a file from a pod to the local filesystem:

kubectl cp my-pod-name:/report.xlsx report.xlsx

copy a file from the local filesystem to a pod:

kubectl cp hello.txt my-pod-name:/world.txt

download kubectl for arm architecture, like an raspberry pi

I don’t know why they make it so hard, but here you go:

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/arm/kubectl"

execute command in pod

one-off command:

kubectl exec rabbitmq-0 -- rabbitmqctl list_queues

run with tty interactively:

kubectl exec -it --tty rabbitmq-0 -- /bin/sh

get kubernetes event log

…sorted by timestamp

kubectl get events --sort-by=.metadata.creationTimestamp

pod / deployment memory usage

kubectl top pods -l app=<appname> --no-headers | awk '{SUM += $3} END { print "Total Memory Usage: " SUM " MiB"}'

port forwarding

you may want to omit --address=0.0.0.0

kubectl port-forward pod-name-here --address=0.0.0.0 8384:8384

get a random local port:

kubectl port-forward pod-name-here --address=0.0.0.0 :8384

run cronjob manually

get list of cron jobs:

kubectl get cronjob
# gickup   0 4 * * * [...]

run a manual job:

kubectl create job --from=cronjob/gickup gickup-run-manual

you might want to delete the job afterwards:

kubectl delete job gickup-run-manual

run one-off pod

example, run the minio/mc container and override the command to end up in a shell instead of the default mc entrypoint

kubectl run -i --tty mc --image=minio/mc --command /bin/sh

run pod with registry secrets

update / replace registry-secret-name and specify your image after --image

kubectl run -i --tty my-container --image=ghcr.io/example/private-image:latest --command /bin/sh --overrides='{ "spec": { "imagePullSecrets": [{"name": "registry-secret-name"}] } }'

logs

get all logs of a deployment

given you have a deployment with the label app=your-app-name and multiple pods in there:

kubectl logs -l app=your-app-name --all-containers

tail logs

this will read the last 100 log entries and also keep following the log for new entries

kubectl logs -f --tail=100 <pod-name>