docker-entrypoint.sh

#!/bin/bash
set -e

set_listen_addresses() {
	sedEscapedValue="$(echo "$1" | sed 's/[\/&]/\\&/g')"
	sed -ri "s/^#?(listen_addresses\s*=\s*)\S+/\1'$sedEscapedValue'/" "$PGDATA/postgresql.conf"
}

if [ "$1" = '/usr/bin/supervisord' ]; then
	mkdir -p "$PGDATA"
	chown -R postgres "$PGDATA"

	chmod g+s /run/postgresql
	chown -R postgres /run/postgresql

	# look specifically for PG_VERSION, as it is expected in the DB dir
	if [ ! -s "$PGDATA/PG_VERSION" ]; then
		gosu postgres initdb

		# check password first so we can output the warning before postgres
		# messes it up
		if [ "$POSTGRES_PASSWORD" ]; then
			pass="PASSWORD '$POSTGRES_PASSWORD'"
			authMethod=md5
		else
			# The - option suppresses leading tabs but *not* spaces. :)
			cat >&2 <<-'EOWARN'
				****************************************************
				WARNING: No password has been set for the database.
				         This will allow anyone with access to the
				         Postgres port to access your database. In
				         Dockers default configuration, this is
				         effectively any other container on the same
				         system.
				         Use "-e POSTGRES_PASSWORD=password" to set
				         it in "docker run".
				****************************************************
			EOWARN

			pass=
			authMethod=trust
		fi

		{ echo; echo "host all all 0.0.0.0/0 $authMethod"; } >> "$PGDATA/pg_hba.conf"

		set_listen_addresses '*' # we're going to start up postgres, but it's not ready for use yet (this is initialization), so don't listen to the outside world yet

		gosu postgres "postgres" &
		pid="$!"
		for i in {30..0}; do
			if echo 'SELECT 1' | psql --username postgres &> /dev/null; then
				break
			fi
			echo 'PostgreSQL init process in progress...'
			sleep 1
		done
		if [ "$i" = 0 ]; then
			echo >&2 'PostgreSQL init process failed'
			exit 1
		fi

		: ${POSTGRES_USER:=postgres}
		: ${POSTGRES_DB:=$POSTGRES_USER}

		if [ "$POSTGRES_DB" != 'postgres' ]; then
			psql --username postgres <<-EOSQL
				CREATE DATABASE "$POSTGRES_DB" ;
			EOSQL
			echo
		fi

		if [ "$POSTGRES_USER" = 'postgres' ]; then
			op='ALTER'
		else
			op='CREATE'
		fi

		psql --username postgres <<-EOSQL
			$op USER "$POSTGRES_USER" WITH SUPERUSER $pass ;
		EOSQL
		echo

		echo
		for f in /docker-entrypoint-initdb.d/*; do
			case "$f" in
				*.sh)  echo "$0: running $f"; . "$f" ;;
				*)     echo "$0: ignoring $f" ;;
			esac
			echo
		done

		if ! kill -s TERM "$pid" || ! wait "$pid"; then
			echo >&2 'No need to kill PostgreSQL since its not running'
		fi

		echo
		echo 'PostgreSQL init process complete; ready for start up.'
		echo
	else
		for f in /docker-entrypoint-initdb.d/*; do
			case "$f" in
				*.sh)  echo "$0: running $f"; . "$f" ;;
				*)     echo "$0: ignoring $f" ;;
			esac
			echo
		done
	fi

	exec "$@"
fi

exec "$@"