Tailscale IP address by hostname with jq

ts-ip-by-hostname.sh

#!/bin/env bash

set -o pipefail

read -r -d '' HELP <<-'HELPDOC'

ts-ip-by-hostname — returns the Tailscale IP address of a connected
                    device by the hostname.

Usage:
  ts-ip-by-hostname <hostname>

Options:
  <hostname>  hostname to match & return IP.
  -h          Show this message.

HELPDOC

help() {
  echo "$HELP"
}

if [[ $1 == "-h" || -z $1 ]]; then
  help
  exit 1
fi

hostname="$1"
read -r -d '' query <<QUERY
.Peer | .[] | select(.HostName == "$hostname") | .TailAddr
QUERY

ip=$(tailscale status --json | jq -r "$query")

if [[ -z $ip ]]; then
  exit 1
fi

echo "$ip"

Even better tailscale ip -4 <hostname>

If you need all IPs (IPv4 and IPv6) omit the -4 or -6.

h/t Ross