Dump command for https://hub.docker.com/_/postgres

dump.sh

#!/usr/bin/env bash
set -Eeo pipefail

# check to see if this file is being run or sourced from another script
_is_sourced() {
	# https://unix.stackexchange.com/a/215279
	[ "${#FUNCNAME[@]}" -ge 2 ] \
		&& [ "${FUNCNAME[0]}" = '_is_sourced' ] \
		&& [ "${FUNCNAME[1]}" = 'source' ]
}

source docker-entrypoint.sh 

_check(){
  PGPASSWORD=$POSTGRES_PASSWORD psql -U $POSTGRES_USER -c &> /dev/null '\q'
}
_wait(){
  echo "Waiting startup..."
  until _check; do
    sleep 1
  done
  echo "Started"
}
_dump(){
  if ! _check; then
    _main postgres &> /dev/null &
    _wait
  fi
  echo "Waiting for a dump to complete..."
  pg_dump -a -U ${POSTGRES_USER} ${POSTGRES_DB:-POSTGRES_USER} > /docker-entrypoint-initdb.d/1_data.sql
  echo "Done"
}
if ! _is_sourced; then
	_dump
fi