#!/usr/bin/env bash

set -Eeo pipefail

file_env() {
	local var="$1"
	local fileVar="${var}_FILE"
	local def="${2:-}"
	if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
		printf >&2 'error: both %s and %s are set (but are exclusive)\n' "$var" "$fileVar"
		exit 1
	fi
	local val="$def"
	if [ "${!var:-}" ]; then
		val="${!var}"
	elif [ "${!fileVar:-}" ]; then
		val="$(< "${!fileVar}")"
	fi
	export "$var"="$val"
	unset "$fileVar"
}

docker_setup_env() {
	file_env 'PGPOOL_ADMIN_USERNAME'
	file_env 'PGPOOL_ADMIN_PASSWORD'
	file_env 'POSTGRES_PGPOOL_USERNAME'
	file_env 'POSTGRES_PGPOOL_PASSWORD'
}

if [ "$(id -u)" = '0' ]; then
  rm /etc/pgpool2/pcp.conf /etc/pgpool2/pgpool.conf
	exec gosu postgres "$BASH_SOURCE"
fi

install --directory --owner postgres --group postgres --mode 700 /var/lib/postgresql/.ssh
cp /ssh/* /var/lib/postgresql/.ssh/
chmod 600 /var/lib/postgresql/.ssh/*

docker_setup_env

{
  printf "%s:" "$PGPOOL_ADMIN_USERNAME"
  pg_md5 "$PGPOOL_ADMIN_PASSWORD"
  printf "\n"
} > /etc/pgpool2/pcp.conf
{
  printf "localhost:9898:%s:%s\n" "$PGPOOL_ADMIN_USERNAME" "$PGPOOL_ADMIN_PASSWORD"
  printf "pgpool:9898:%s:%s\n" "$PGPOOL_ADMIN_USERNAME" "$PGPOOL_ADMIN_PASSWORD"
} > ~/.pcppass
chmod 600 /etc/pgpool2/pcp.conf ~/.pcppass

{
  printf "listen_addresses = '*'\n"
  printf "port = 5432\n"
  printf "unix_socket_directories = '/run'\n"
  printf "pcp_socket_dir = '/run'\n"
  printf "enable_pool_hba = off\n"
  printf "allow_clear_text_frontend_auth = on\n"
  printf "process_management_mode = 'dynamic'\n"
  printf "backend_clustering_mode = 'raw'\n"
  printf "health_check_timeout = 5\n"
  printf "health_check_period = 5\n"
  printf "health_check_user = 'pgpool'\n"
  printf "health_check_password = '%s'\n" "$PGPOOL_PASSWORD"

  IFS=':'
  n=0
  for backend in $PGPOOL_BACKEND
  do
    printf "backend_hostname%d = '%s'\n" $n $backend
    printf "backend_port%d = 5432\n" $n
  ((n+=1))
  done
} > /etc/pgpool2/pgpool.conf


service ssh start
/usr/sbin/pgpool

while true
do
  echo "$(date)"
  sleep 3600
done