A Powerlevel10k prompt segment for your VAULT_ADDR

.zshrc

# Create a Powerlevel10k prompt segment that shows that value of $VAULT_ADDR if set.
function prompt_my_vault_addr() {                                       
  if [[ -n $VAULT_ADDR ]]; then                                         
    p10k segment -i '🔐' -f brightwhite -b blue -t "$VAULT_ADDR"        
  fi                                                                    
}                                                                       

# Add it to the right prompt.                                           
POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS+=my_vault_addr                       

# Only show it when running 'vault'.                                    
typeset -g POWERLEVEL9K_MY_VAULT_ADDR_SHOW_ON_COMMAND='vault'           

A more subtle color option:

function prompt_my_vault_addr() {
  if [[ -n $VAULT_ADDR ]]; then
    p10k segment -i 'LOCK_ICON' -r -f black -b cyan -t "$VAULT_ADDR"
  fi
}

There's an actual Hashicorp Vault icon in the devicons/devicon project: devicons/devicon#1609

Powerlevel10k uses NerdFonts, which includes an unmaintained version of devicons (vorillaz/devicons).

The devicons/devicon project is actively maintained and has more icons, and NerdFonts is trying to migrate to the newer project, but that hasn't completed yet: ryanoasis/nerd-fonts#615