Script for DAPS to wait for a service to come available on a certain port before returning

wait-for-port.sh

#!/bin/bash

MAX_ATTEMPTS=120

if [[ -z "$1" ]]; then
  HOST="localhost"
else
  HOST="$1"
fi

if [[ -z "$2" ]]; then
  PORT="1636"
else
  PORT="$2"
fi

ATTEMPTS=1
while : ; do
  nc -w 1 -z "$HOST" "$PORT"
  STATUS=$?
  [[ $STATUS -eq 1 && $ATTEMPTS -lt $MAX_ATTEMPTS ]] || exit $STATUS
  ((ATTEMPTS=ATTEMPTS+1))
done