Enable Tailscale Subnet Routes via API

tailscale-enable-subnet-routes.sh

#!/usr/bin/env sh

set -e

if [ "$TAILSCALE_APIKEY" = "" ]; then
  echo "Missing TAILSCALE_APIKEY environment variable, exiting"; exit 21
fi

NAME="$(hostname -f)"
TAILSCALE_API="https://api.tailscale.com/api/v2"
TAILSCALE_NET="yourDomain.com"
# jq can create this output for you if the cidrs are in an array
# echo '{"cidrs": ["10.0.0.0/24","10.0.1.0/24"]}' | jq -r '.cidrs | @csv'
TAILSCALE_SUBNET_ROUTES='"10.0.0.0/24","10.0.1.0/24"'

# Dependencies for Alpine Linux
if [ -f "/etc/alpine-release" ]; then
  echo "Installing curl & jq"
  apk add jq curl
fi

echo "Hostname: $NAME"
echo "Routes:   $TAILSCALE_SUBNET_ROUTES"
echo "Searching for this machine in the list of registered machines..."

INDEX=0
# Search for the device (machine), if it was just registered and it doesn't return at first we'll keep trying
while [ "$DEVICE_ID" = "" ]; do
  DEVICE_ID=$(
    curl -s --retry 5 -u "${TAILSCALE_APIKEY}:" "${TAILSCALE_API}/tailnet/${TAILSCALE_NET}/devices" | \
      jq -r --arg HOSTNAME "$NAME" '.devices[] | select(.hostname==$HOSTNAME) | .id'
  )

  # Timeout after ~5 minutes
  if [ $INDEX -gt 55 ]; then
    echo "Timeout: Unable to find $NAME in the list of registered machines"
    exit 22
  fi

  if [ "$DEVICE_ID" = "" ]; then
    INDEX=$(( $INDEX + 1 ))
    sleep 5
  fi
done

echo "Found this machine registered with ID: $DEVICE_ID"

echo "Enabling routes:"
curl -s --retry 5 -u "${TAILSCALE_APIKEY}:" "${TAILSCALE_API}/device/${DEVICE_ID}/routes"  \
        --data-binary "{\"routes\": [${TAILSCALE_SUBNET_ROUTES}]}" | jq .