kube-tmux: Kubernetes context and namespace status for tmux

A script that lets you add the current Kubernetes context and namespace configured on kubectl to your tmux status line.

Inspired by kube-ps1, this is a port to tmux that includes all the features that make kube-ps1 efficient and brings it to the tmux status line.

Disclaimer

This plugin is actively under development, with lots of updates on the way — including a full restructure to work with TPM, tons of bug fixes, and style improvements. Expect frequent changes. Some updates might break things here and there, but I’ll be quick to patch them.

If you have any bug reports, please feel free to submit a PR, or a bug report.

Installing

Manual

Clone this repository to your $HOME/.tmux directory, and add the following line to your ~/.tmux.conf:

set -g status-right "#(/bin/bash $HOME/.tmux/kube-tmux/kube.tmux 250 red cyan)"

250 is the color selection for the default foreground, red for the context, and cyan for the namespace.

TPM (Recommended)

set -g @plugin 'tmux-plugins/tpm' # mandatory
set -g @plugin 'jonmosco/kube-tmux'

Requirements

• tmux
• kubectl and/or oc

Plugin Structure

The default plugin layout is:

<symbol> <cluster>:<namespace>

If the current-context is not set, kube-tmux will return the following:

<symbol> N/A:N/A

Customization

Colors for the default text, context, and namespace can be changed via positional arguments:

#(/bin/bash $HOME/.tmux/kube-tmux/kube.tmux text context namespace)

Configuration Variables

The following environment variables can be used to customize the plugin. These can be set in your ~/.tmux.conf or your shell profile.

Variable	Default	Meaning
KUBE_TMUX_BINARY	kubectl	Kubernetes binary to use
KUBE_TMUX_SYMBOL_ENABLE	true	Enable/disable symbol display
KUBE_TMUX_SYMBOL_DEFAULT	\u2388	Default symbol to display
KUBE_TMUX_SYMBOL_USE_IMG	false	Use alternative symbol image
KUBE_TMUX_CONTEXT_ENABLE	true	Enable/disable context display
KUBE_TMUX_NAMESPACE_ENABLE	true	Enable/disable namespace display
KUBE_TMUX_DIVIDER	:	Divider between context and namespace
KUBE_TMUX_SYMBOL_COLOR	blue	Color for the symbol
KUBE_TMUX_CTX_COLOR	red	Color for the context
KUBE_TMUX_NS_COLOR	cyan	Color for the namespace
KUBE_TMUX_TEXT_COLOR	colour250	Color for the divider and reset text
KUBE_TMUX_CLUSTER_FUNCTION	No default	Function to customize how cluster is displayed
KUBE_TMUX_NAMESPACE_FUNCTION	No default	Function to customize how namespace is displayed

Custom Functions

You can customize how the context and namespace are displayed by defining shell functions and exporting them via environment variables.

Variable	Meaning
KUBE_TMUX_CLUSTER_FUNCTION	Function to customize how the context/cluster is displayed
KUBE_TMUX_NAMESPACE_FUNCTION	Function to customize how the namespace is displayed

Each function receives the current value as its first argument and should echo the transformed value.

For example, if your cluster name is sandbox.k8s.example.com and you only want to display sandbox:

function get_cluster_short() {
    echo "$1" | cut -d . -f1
}

export KUBE_TMUX_CLUSTER_FUNCTION=get_cluster_short

To display the namespace in uppercase:

function get_namespace_upper() {
    echo "$1" | tr '[:lower:]' '[:upper:]'
}

export KUBE_TMUX_NAMESPACE_FUNCTION=get_namespace_upper

Important: These functions and variables must be defined and exported before kube-tmux is loaded in your tmux configuration. If you are using TPM, ensure you set these in your shell profile (e.g., .bashrc, .zshrc) or in a sourced script before launching tmux.

You can also place custom functions in ~/.tmux/config/kube-func.sh. This file is automatically sourced by kube-tmux if it exists, making it a convenient place to keep your customizations separate from your shell profile.

Example for manual setup in ~/.tmux.conf:

# In your shell profile (before starting tmux)
function get_cluster_short() {
    echo "$1" | cut -d . -f1
}
export KUBE_TMUX_CLUSTER_FUNCTION=get_cluster_short

# In your ~/.tmux.conf
set -g status-right "#(/bin/bash $HOME/.tmux/kube-tmux/kube.tmux 250 red cyan)"