custom color depending on context does not update within current shell

[ranvit]

I have the following in my .zshrc

autoload -U colors; colors
source $(brew ls zsh-kubectl-prompt | grep 'kubectl.zsh')
[[ "$(kubectl config current-context)" =~ "PRODUCTION" ]] && color=red || color=green
RPROMPT='%{$fg[$color]%}[$ZSH_KUBECTL_PROMPT]%{$reset_color%}'
# customization
zstyle ':zsh-kubectl-prompt:' separator '|' 

I want the color of the prompt to be red if my context is the production cluster.

For starters, I was unable to use ZSH_KUBECTL_CONTEXT (it doesn't get set in my environment), so I'm calling kubectl config current-context again

My problem:

Suppose I'm on my development context, the prompt color is green. Then I switch my context to production - I expect to see the prompt color change to red. It remains green instead of changing to red.
However, opening a new shell forces the prompt color to change to red.

I'm probably not doing something correct, please help.

[ranvit]

I figured out that this line is not updating the $color variable when we are switching kubernetes contexts.

[[ "$(kubectl config current-context)" =~ "PRODUCTION" ]] && color=red || color=green

Manually setting the $color variable immediately updates the prompt color

color=blue

[ranvit]

GOT IT

Someone feel free to correct my work.

So, this is the important line where color is being set into the right-prompt. Whatever RPROMT contains is what gets re-executed on every terminal entry/command.

RPROMPT='%{$fg[$color]%}[$ZSH_KUBECTL_PROMPT]%{$reset_color%}'

And from my previous comment we know that the `$color variable is not getting re-calculated. Thats because this line is not getting re-run on every terminal command

[[ "$(kubectl config current-context)" =~ "PRODUCTION" ]] && color=red || color=green

---

The solution

is to put that color calculation logic into the RPROMPT. This works for me now! Like so

RPROMPT='%{$fg[$([[ "$(kubectl config current-context)" =~ "aks-prod" ]] && echo red || echo green)]%}[$ZSH_KUBECTL_PROMPT]%{$reset_color%}'

---

On a different note, I found it nicer to set the background color to red/green as opposed to the foreground. This is what I'm using

RPROMPT='%{$bg[$([[ "$(kubectl config current-context)" =~ "PRODUCTION" ]] && echo red || echo green)]$fg[black]%}[$ZSH_KUBECTL_PROMPT]%{$reset_color%}'

[superbrothers]

I'm sorry for the late reply.

The solution

is to put that color calculation logic into the RPROMPT. This works for me now! Like so

RPROMPT='%{$fg[$([[ "$(kubectl config current-context)" =~ "aks-prod" ]] && echo red || echo green)]%}[$ZSH_KUBECTL_PROMPT]%{$reset_color%}'

zsh-kubectl-prompt creates the followting 4 variables:

• ZSH_KUBECTL_CONTEXT
• ZSH_KUBECTL_NAMESPACE
• ZSH_KUBECTL_PROMPT
• ZSH_KUBECTL_USER

So, using ZSH_KUBECTL_CONTEXT, you can do the following:

RPROMPT='%{$fg[$([[ "$ZSH_KUBECTL_PROMPT" =~ "aks-prod" ]] && echo red || echo green)]%}[$ZSH_KUBECTL_PROMPT]%{$reset_color%}'

This is light way because it does not run kubectl config current-context command.

If you have more complicated conditions, I recommend to define it as a function.

function right_prompt() {
  local color="green"

  if [[ "$ZSH_KUBECTL_CONTEXT" =~ "aks-prod" ]]; then
    color="red"
  fi

  echo "%{$fg[$color]%}[$ZSH_KUBECTL_PROMPT]%{$reset_color%}"
}

RPROMPT='$(right_prompt)'