docker-entrypoint.sh

#!/bin/bash
set -e

if [ "$1" = 'postgres' ]; then
	chown -R postgres "$PGDATA"
	
	if [ -z "$(ls -A "$PGDATA")" ]; then
		gosu postgres initdb
		
		sed -ri "s/^#(listen_addresses\s*=\s*)\S+/\1'*'/" "$PGDATA"/postgresql.conf
		
		# check password first so we can ouptut 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.
				         Use "-e POSTGRES_PASSWORD=password" to set
				         it in "docker run".
				****************************************************
			EOWARN
			
			pass=
			authMethod=trust
		fi
		
		: ${POSTGRES_USER:=postgres}
		if [ "$POSTGRES_USER" = 'postgres' ]; then
			op='ALTER'
		else
			op='CREATE'
			gosu postgres postgres --single -jE <<-EOSQL
				CREATE DATABASE "$POSTGRES_USER" ;
			EOSQL
			echo
		fi
		
		gosu postgres postgres --single -jE <<-EOSQL
			$op USER "$POSTGRES_USER" WITH SUPERUSER $pass ;
		EOSQL
		echo
		
		{ echo; echo "host all \"$POSTGRES_USER\" 0.0.0.0/0 $authMethod"; } >> "$PGDATA"/pg_hba.conf
		
		if [ -d /docker-entrypoint-initdb.d ]; then
			for f in /docker-entrypoint-initdb.d/*.sh; do
				[ -f "$f" ] && . "$f"
			done
		fi
	fi
	
	exec gosu postgres "$@"
fi

exec "$@"