How to fix kubectl unknown shorthand flag: 'f' in -f

Problem:

You want to run a Kubernetes kubectl command like

kubectl -f my-app-deployment.yaml

but you see this error message after kubectl prints its entire help page:

unknown shorthand flag: 'f' in -f

Solution

You are missing an actual command to kubectl. Most likely you want create something on your Kubernetes instance, in which case you want to run this instead:

kubectl create -f my-app-deployment.yaml

You might also want to apply or replace your config instead. Note that apply does not automatically restart your Kubernetes Pods. Read How to fix Kubernetes kubectl apply not restarting pods for more information.