Postgres docker `docker-entrypoint-initdb.d` script to add non-superuser user/password

init_db-user.sh

#!/usr/bin/env bash

####################################################################################################
# Initializes a new non-superuser user and password for use with the database
#
# This may be officially supported soon: https://github.com/docker-library/postgres/issues/175

main() {
	file_env 'POSTGRES_DB_USER'
	file_env 'POSTGRES_DB_PASSWORD'

	if [ "$POSTGRES_DB_USER" ] && [ "$POSTGRES_DB_PASSWORD" ] && [ "$POSTGRES_DB" ]; then
		"${psql[@]}" <<-EOSQL
			CREATE ROLE "$POSTGRES_DB_USER" WITH NOSUPERUSER LOGIN PASSWORD '$POSTGRES_DB_PASSWORD' ;
			GRANT ALL PRIVILEGES ON DATABASE "$POSTGRES_DB" TO "$POSTGRES_DB_USER" ;
		EOSQL
	else
		error-exit "POSTGRES_DB_USER, POSTGRES_DB_PASSWORD, POSTGRES_DB must all be set."
	fi
}

error-exit() {
	echo "$1" >&2
	echo
	exit 1
}

main "$@"