Powerkube

Powerkube is a Powerline segment that shows your current Kubernetes context. It can be configured to show any or all of:

• the current cluster
• the current namespace
• the current user

Two other nifty features that it has are:

1. The ability to toggle on or off the powerkube segment using an environment variable which can easily be mapped to a function in your ~/.bash_profile.
2. The ability to define certain namespaces to be colored differently for alerting purposes. For example, you could have your production namespaces show up in bright red.

The screenshot below demonstrates this functionality:

Note that powerkube currently only supports Python 2.7 due to a dependency, kubernetes-py, only being Python 2.7 compatible.

Installation

1. Add the Python package. Powerkube is available on pypi so you can install it with pip:

   pip install --user powerkube

2. Create a user configuration directory. Once powerkube has been installed, we'll need to add it to our powerline shell's theme and colorscheme. The best way to do this is to alter our powerline user config, which will override the powerline defaults. If you don't already have a ~/.config/powerline/ folder, create it. Next we'll be copying some of the default powerline configs into this location. Find where powerline is installed by using pip show powerline-status | grep 'Location', then navigate to the config_files/ folder there. We'll be copying config.json, themes/shell/default.json, and colorschemes/shell/default.json to our ~/.config/powerline/ folder, adding the necessary folders to match that original file structure (i.e. adding the themes/ and colorschemes/ folders, etc.

3. Add powerkube to your user config. Within our user config, we'll need to add the powerkube segment to our shell by adding the following lines to our ~/.config/powerline/themes/shell/default.json:

   {
       "function": "powerkube.context",
       "priority": 30,
       "args": {"show_cluster": true,
   	     "show_namespace": true,
   	     "show_user": true,
   	     "alert_namespaces": ["data-prod", "infra-prod"]}
   }

   Next we'll add the highlighting colors we'll use to our ~/.config/powerline/colorschemes/shell/default.json:

   {
       "name": "Default",
       "groups": {
   	    "kubernetes_cluster":         { "fg": "white", "bg": "gray6",     "attrs": [] },
   	    "kubernetes_namespace":       { "fg": "white", "bg": "gray8",     "attrs": [] },
   	    "kubernetes_namespace:alert": { "fg": "white", "bg": "brightred", "attrs": [] },
   	    "kubernetes_user":            { "fg": "white", "bg": "gray9",     "attrs": [] }
       }
   }

4. You may need to reload powerline with powerline-daemon --replace to load the new settings. That's it!

5. (Optional) By default powerkube will render the kubernetes context if the enviroment variable RENDER_POWERLINE_KUBERNETES is either set to YES or is not set at all. Rather than setting this variable manually, you can create a simple kshow function by placing the following in your ~/.bash_profile:

   kshow() {
       if [[ $RENDER_POWERLINE_KUBERNETES = "NO" ]]; then
       export RENDER_POWERLINE_KUBERNETES=YES
       else
       export RENDER_POWERLINE_KUBERNETES=NO
       fi
   }

You're all set up! Happy coding!

License

Licensed under the Apache License 2.0.