Prompt command to track GCert expiration

Basics

This provides a function, useful in $PROMPT, for showing the time left until certificate expiration. It monitors your command history, grepping for when you run gcert, and updates the file .gcert_expiration¹ with the expiration time when you do. Then it displays the time remaining before certificate expiration when you run the command.

With Oh-My-Zsh

To use it, copy the gcert directory (/google/data/ro/users/mw/mweigel/oh-my-zsh/plugins/gcert) to your custom plugin directory (by default this would be ~/.oh-my-zsh/custom/plugins) and add gcert to the plugins array in your zshrc file:

plugins=(... gcert)

Without Oh-My-Zsh

If you aren't using Oh-My-Zsh, copy the file gcert.plugin.zsh somewhere local on your workstation and source it from your zshrc file. For example if you copied it to ~/.gcert.plugin.zsh then you might add

source ~/.gcert.plugin.zsh

To your zshrc.

With Powerlevel9k / Powerlevel10k

Follow the above OMZ/not-OMZ instructions, and add gcert to POWERLEVEL9K_LEFT_PROMPT_ELEMENTS or POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS.

Customization

For Normal PROMPT

To see the gcert expiration time in your prompt, add $(gcert_prompt_time) somewhere in $PROMPT.

To change the file used for caching expiration time, set ZSH_THEME_GCERT_EXPIRY_FILE after the script loads.

You can set the duration (in hours) at which you want to change the display of the duration by setting the variable ZSH_THEME_GCERT_PROMPT_WARN_HOURS (the default is 2, for 2 hours).

You can decorate the display with ZSH_THEME_GCERT_PROMPT_PREFIX and ZSH_THEME_GCERT_PROMPT_POSTFIX or, in the warning state, with ZSH_THEME_GCERT_PROMPT_WARN_PREFIX and ZSH_THEME_GCERT_PROMPT_WARN_POSTFIX.

You can disable checking your history by setting ZSH_THEME_GCERT_PROMPT_PARANOID to "true". If you do that, you can still trigger an update to the file by running gcert_update_expiry.

State for Powerlevel9k/Powerlevel10k

The gcert prompt segment has EXPIRED, LOW, and NORMAL states. You can set POWERLEVEL9K_GCERT_LOW_THRESHOLD to the number of hours left that triggers the LOW state instead of NORMAL. You can set foreground/background colors as usual for a segment with states: POWERLEVEL9K_GCERT_{STATE}_(FOREGROUND,BACKGROUND).

You can also customize the messages with POWERLEVEL9K_GCERT_{STATE}_MESSAGE.

Changes

The code for this plugin resides in google3/experimental/users/mweigel/oh-my-zsh/plugins/gcert/. CLs are gratefully reviewed, just add reviewer: mweigel

The cached expiration timestamp is put in $ZSH_CACHE_DIR if that variable is defined (it should be for Oh-My-Zsh). Otherwise if $XDG_CACHE_HOME is set and exists, it will use that. If neither variable is set but $HOME/.cache exists, it will use that; and as a fallback it will use $HOME. ↩︎