fix(kubectx): fix display of k8s contexts without double quotes (#12534)

BREAKING CHANGE: the `kubectx` plugin now properly displays contexts from the
kubectx_mapping array, without using double quotes. Please refer to the plugin
README to see how to use it properly.

Closes #12534

Co-authored-by: Ken Kelly <ken@kenhkelly.us>

plugins/kubectx/README.md

@@ -1,25 +1,55 @@
 # kubectx - show active kubectl context
 
-This plugins adds ```kubectx_prompt_info()``` function. It shows name of the
-active kubectl context (```kubectl config current-context```).
+This plugins adds `kubectx_prompt_info()` function. It shows name of the active
+kubectl context (`kubectl config current-context`).
 
 You can use it to customize prompt and know if You are on prod cluster ;)
 
-_Example_. Add to **.zshrc**:
+To use this plugin, add `kubectx` to the plugins array in your zshrc file:
 
+```zsh
+plugins=(... kubectx)
 ```
+
+### Usage
+
+Add to **.zshrc**:
+
+```zsh
+# right prompt
 RPS1='$(kubectx_prompt_info)'
+# left prompt
+PROMPT="$PROMPT"'$(kubectx_prompt_info)'
 ```
 
-### custom ctx names
+### Custom context names
 
-One can rename default context name for better readability.
+You can rename the default context name for better readability or additional formatting.
+These values accept [prompt expansion sequences](http://zsh.sourceforge.net/Doc/Release/Prompt-Expansion.html)
+such as `%F{color}`, `%f`, `%K{color}`, `%k`, `%B`, `%b`, `%U`, `%u`, `%S`, `%s`, `%{...%}`.
 
-_Example_. Add to **.zshrc**:
+**Example**: add this to your .zshrc file:
+
+```zsh
+kubectx_mapping[minikube]="mini"
+kubectx_mapping[context_name_from_kubeconfig]="$emoji[wolf_face]"
+kubectx_mapping[production_cluster]="%{$fg[yellow]%}prod!%{$reset_color%}"
+# contexts with spaces
+kubectx_mapping[context\ with\ spaces]="%F{red}spaces%f"
+# don't use quotes as it will break the prompt
+kubectx_mapping["context with spaces"]="%F{red}spaces%f" # ti
 ```
-kubectx_mapping["minikube"]="mini"
-kubectx_mapping["context_name_from_kubeconfig"]="$emoji[wolf_face]"
-kubectx_mapping["production_cluster"]="%{$fg[yellow]%}prod!%{$reset_color%}"
+
+You can also define the whole mapping array at once:
+
+```zsh
+typeset -A kubectx_mapping
+kubectx_mapping=(
+  minikube                      "mini"
+  context_name_from_kubeconfig  "$emoji[wolf_face]"
+  production_cluster            "%{$fg[yellow]%}prod!%{$reset_color%}"
+  "context with spaces"         "%F{red}spaces%f"
+)
 ```
 
 ![staging](stage.png)

plugins/kubectx/kubectx.plugin.zsh

@@ -7,7 +7,9 @@ function kubectx_prompt_info() {
 
   [[ -n "$current_ctx" ]] || return
 
-  # use value in associative array if it exists
-  # otherwise fall back to the context name
-  echo "${kubectx_mapping[\"$current_ctx\"]:-${current_ctx:gs/%/%%}}"
+  # Use value in associative array if it exists, otherwise fall back to the context name
+  #
+  # Note: we need to escape the % character in the prompt string when coming directly from
+  # the context name, as it could contain a % character.
+  echo "${kubectx_mapping[$current_ctx]:-${current_ctx:gs/%/%%}}"
 }