Server Startup Time

startup.sh

#!/bin/bash
set -eo pipefail

#
# Test server startup times using crude scripting
#
# Use:
#
#   time CMD="npm start" URL=localhost:3000 ./startup.sh
#

START_TIME=$(date +%s)
RETRY_COUNT=0

bash -c "$CMD" &> /dev/null &

while [ "$(curl -fks "$URL" &> /dev/null; echo $?)" -gt 0 ] && [ "$RETRY_COUNT" -lt 1000 ]; do
  RETRY_COUNT=$((RETRY_COUNT + 1))
  sleep 0.1
done

END_TIME=$(date +%s)

echo "Duration: $(bc <<< "$END_TIME - $START_TIME") seconds"

kill -9 $! # stop background command