Local service instrumentation

run_services.bash

#!/usr/bin/env bash

# This script runs services in the background, logs their output, and spins them down gently
#
# I use it in development, since I don't want to have databases and message brokers running
# all the time on my laptop.
#
# Reads a list of services either from ARGV or from a ".services" file
# Alternatively, can take a list of services (from either source) in label=command format

function cleanup_from_pid_file() {
  # send a SIGINT for a graceful shutdown
  kill -2 $(cat $1) >/dev/null 2>&1
  sleep 3
  kill -0 $(cat $1) >/dev/null 2>&1
  if [[ $? -eq 1 ]]; then
    rm $1
    exit 0
  fi
  # a bit more insistent this time, send them SIGTERM
  kill -15 $(cat $1) >/dev/null 2>&1
  sleep 10
  kill -0 $(cat $1) >/dev/null 2>&1
  if [[ $? -eq 1 ]]; then
    rm $1
    exit 0
  fi
  # leave it to the user to send SIGKILL
  exit 1
}

function cleanup() {
  for label in "$@"; do
    cleanup_from_pid_file ".${label}.pid" &
  done
}

function map_service() {
  case "$1" in
    postgresql|postgres|pgsql|pg|psql)
      echo "postgres=postgres -D /usr/local/var/postgres"
      ;;
    redis)
      echo "redis=redis-server /usr/local/etc/redis.conf"
      ;;
    memcached|memcache|mcache|memc)
      echo "memcached=memcached"
      ;;
    rabbitmq|rmq)
      echo "rabbitmq=rabbitmq-server"
      ;;
    mongodb|mongo)
      echo "mongodb=mongod --dbpath=.mongodb"
      ;;
    mailcatcher|mailc)
      echo "mailcatcher=mailcatcher -f"
      ;;
    *)
      echo "$1=$@"
      ;;
  esac
}

function main() {
  if [[ $# -gt 0 ]]; then
    local services=( "$@" )
  elif [[ -s "./.services" ]]; then
    local -a services
    mapfile services < ./.services
  else
    local services=( )
  fi

  if [[ ${#services[@]} -eq 0 ]]; then
    echo "Usage: run_services SERVICES"
    echo "Or list services to run in a .services file"
    exit 1
  fi
  local -a labels
  local -a commands
  for i in ${!services[@]}; do
    services[$i]=$( map_service ${services[$i]} )
    labels[$i]="${services[$i]/%=*/}"
    commands[$i]="${services[$i]:((${#labels[$i]} + 1))}"
  done
  trap "cleanup ${labels[@]}; exit" SIGHUP SIGINT SIGTERM
  for i in ${!services[@]}; do
    ${commands[$i]} > .${labels[$i]}.log &
    echo $! > .${labels[$i]}.pid
  done
  while true; do
    sleep 10
  done
}

main "$@"