FZF is general purpose option selector for Linux command line. By default fzf is an super-upgrade for the ctrl-r command history finder, but it is helpful for almost any scenario where you need to pick 1 item from a list.

Here’s a tiny use case where I use fzf to select a kubernetes namespace and set it as the default namespace, just to save the effort to type --namespace flag everytime when I need to do something not in the default namespace.

#!/bin/bash
function kns() {
   cns=$(kubectl get namespaces --output=jsonpath='{range .items[*]}{.metadata.name}{"\n"}{end}'|fzf)
   kubectl config set-context --current --namespace=$cns
}

Let me explain the script above step by step:

1. kubectl get namespaces will list all namespaces currently accessible
2. --output=jsonpath='{range .items[*]}{.metadata.name}{"\n"}' will only output the name of namespaces and 1 in each line
3. |fzf to pipe the result from step 2 to fzf, a list will popup and becomes interactive for the user to choose one.
4. kubectl config set-context --current --namespace=$cns will set the chosen namespace from step 3 as the default namespace

This is very convenient when there are not too many namespaces and when you need to work in different namespaces randomly. 🙂