sahil1610/kc

Kubernetes context changing CLI utility function that works per-shell, not globally

kc

kc is a tool, in the spirit of kubectx/kubens, that allows you to easily work in multiple Kubernetes contexts. Its main point of difference is that it manages a local context only; it changes context per shell, not globally, so you can run commands against two clusters, in different terminals, at the same time.

This means you're less likely to change contexts in one shell, and then accidentally run against the production cluster in a different shell where your kube-ps1 says minikube. (In other words, it works around the lack of a KUBECONTEXT environment variable.)

Usage

  kc <CONTEXT>             : switches to the given context
  kc <CONTEXT> <NAMESPACE> : switches to the given context and namespace in the current shell
  kc                       : reset your shell to use your default context and namespace

Installation

Bash

• Copy kc-init.sh somewhere (doesn't have to be on the PATH)

• Source it in your ~/.bashrc:

  if [[ -f ~/.path/to/kc-init.sh ]]; then
    source ~/.path/to/kc-init.sh
  fi

• Copy completion/kc.bash to your bash completion dir (e.g. for Homebrew on Mac OS X, this is /usr/local/etc/bash_completion.d):

  cp completion/kc.bash /usr/local/etc/bash_completion.d

oh-my-zsh

• Copy or link kc-init.sh into your ~/.oh-my-zsh/custom directory with a .zsh file extension:

  cp kc-init.sh ~/.oh-my-zsh/custom/kc-init.zsh

• Copy completion/kc.zsh to your ~/.oh-my-zsh/completions directory:

  mkdir -p ~/.oh-my-zsh/completions
  cp completion/kc.zsh ~/.oh-my-zsh/completions/

Other Features

kc has a few extra features for users of iTerm2 and/or EKS:

• kc can alias common tools like helm/kubectl to work with EKS via IAM authentication, by making use of aws-vault - to enable this feature, set KC_EKS_ALIASES=1
• Under iTerm2 kc can optionally change tab color depending on the context name
• Under iTerm2 kc will set the kubecontext and kubens user variables - these can be used to put the current context/namespace in the status bar

Configuration

kc supports the following environment variables that can alter its behavior:

env	default	behavior
KC_KUBE_PS1_TOGGLE	1	Whether to turn the kube-ps1 prompt display on and off automatically based on whether kc has set an active context
KC_ITERM_USER_VAR	1	Whether to set the iTerm2 user variables kubecontext/kubens to the current context/namespace when it changes
KC_ITERM_TAB_COLOR	0	Whether to change the iTerm2 tab color automatically based on the context name (e.g. red for prod anywhere in the context name)
KC_EKS_ALIASES	0	Whether to alias kubectl and helm to use AWS IAM authentication via aws-vault
KC_EKS_ASSUME_ROLE_TTL	60m	Passed to aws-vault as --assume-role-ttl

Limitations

• When kc is configured for EKS, it always uses aws-vault authentication and assumes your context name is the same as your AWS authentication profile name
• kc has only been tested on Mac OS X so far