Zsh, iTerm2, and Kubectl

This repo holds my personal config for my shell. Over time, I've adopted zsh as my shell (with a custom oh-my-zsh theme), iTerm2 badges, and some helpers to make my Kubectl experience better.

Install and use

If you wish to install/use this, you can either use the shell helpers in this repo, or preferrably, install them from the original sources:

1. oh-my-zsh
2. iTerm2 shell integration

Kubectl and iTerm2 badges

Sometimes, it's really useful to know which Kubernetes config the shell is pointing at. On a daily basis, I may be connecting and switching between multiple Kubernetes clusters, and had to come up with a way to know to which cluster my kubectl command was going to. So here are some helpful tools with that.

Alias

The simplest one is to alias kubectl:

alias k='kubectl'

Kubectl config files

Kubectl allows you to have multiple Kubernetes cluster connection config in a single file, calling them a "context". I found this hard to use, as I couldn't have 2 different terminal windows talking to 2 different clusters and share the single file. So I've gone with having separate "kubeconfig" files for each cluster, each having a single "context". This means NOT having a `~/.kube/config" file, and each time some installer/tool creates one, I make sure to rename it.

To switch between them, I just set the KUBECONFIG env var to the shell:

export KUBECONFIG=~/.kube/my-test-cluster

Helper tools like ktx can help here.

iTerm2 badges

Unfortunately, sometimes it's hard to remember which KUBECONFIG is set on a terminal. To help provide a signal, I chose to have my iTerm2 terminal have a "badge" with this info.

The .shell/it2badges script sets up a zsh precmd(), which is run before each prompt and uses the KUBECONFIG value as a badge. The result is something like this:

Each time a KUBECONFIG changes, the badge should reflect it. This provides a quick visual check as to which Kubeconfig it's using.

Kubernetes namespace

Another typing intensive item with kubectl is that any command to a specific namespace requires you to type -n <namespace> or --namespace <namespace>. Since I often work within a single namespace at a time, it'd be nice to save all that typing.

Here, kubectl can help you, but it's not as trivial. So, the bin/kn script helps you set this:

#/bin/sh

export CUR_CTX=$(kubectl config current-context)
kubectl config set-context ${CUR_CTX} --namespace=$1

So, if you're doing a lot of work in a my-dev-space namespace, you can now:

# Before
$ kubectl get pods -n my-dev-space
$ kubectl get pod pod-1234 -n my-dev-space -o yaml

# Set the namespace
$ kn my-dev-space

# After
$ kubectl get pods 
$ kubectl get pod pod-1234 -o yaml

AWS-vault

If you do a lot of AWS work, another tool I'd recommend is AWS Vault. The iTerm2 badge script above will also show which AWS context it's currently set.