postgresql: improve init script

Use newly introduced procd_add_restart_mount_trigger to make sure
postmaster gets started only once PGDATA becomes available.
Relocate socket directory to /var/lib/postgresql to make it possible
to run postgresql inside a ujail.
Use signal for shutdown, so it works nicely with jail.
Allow multiple script in UCI 'config postgres-db' to be a list and
run them in order listed.
User more silent methods to check for db or role existence and make
it easy to create several databases owned by the same user by passing
the same credentials multiple times.
Remove disfunctional reload handler.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

libs/postgresql/files/postgresql.init

@@ -32,40 +32,57 @@ start_service() {
 	user_exists postgres 5432 || user_add postgres 5432
 	group_exists postgres 5432 || group_add postgres 5432
 
+	[ "$_BOOT" = "1" ] &&
+		[ "$(procd_get_mountpoints $pgdata)" ] && return 0
+
 	fix_perms
 	fix_hosts
 
-	if [ ! -d "${pgdata}" ]; then
+	if [ ! -e "${pgdata}/PG_VERSION" ]; then
 		pg_init_data ${pgdata}
 		[ $? -gt 0 ] && return 1
 	fi
 
 	cleanup "${pgdata}"
 
-	procd_open_instance
+	mkdir -m 0755 -p /var/run/postgresql
+	chmod 0750 /var/run/postgresql
+	chown postgres:postgres /var/run/postgresql
+	procd_open_instance postmaster
 	procd_set_param user postgres
 	procd_set_param command $PROG
 	procd_append_param command -D "${pgdata}"
+	procd_append_param command -k "/var/run/postgresql"
 	[ -n "${pgopts}" ] && procd_append_param command -o "${pgopts}"
 	procd_set_param respawn retry=60
+	procd_add_jail postgresql log
+	procd_add_jail_mount /usr/lib/postgresql /usr/share/postgresql
+	procd_add_jail_mount_rw /var/run/postgresql "${pgdata}"
+	procd_add_jail_mount_rw /dev/shm
+	procd_set_param stderr 1
+	procd_set_param stdout 1
 	procd_close_instance
 
-	procd_open_instance
+	procd_open_instance uci_dbinit
 	procd_set_param user postgres
 	procd_set_param command /lib/functions/postgresql.sh init "${pgdata}"
+	procd_set_param stdout 1
+	procd_set_param stderr 1
 	procd_close_instance
 }
 
-reload_service() {
+boot() {
+	_BOOT=1 start
+}
+
+service_triggers() {
 	config_load "postgresql"
 	config_get pgdata config PGDATA
-	/usr/bin/pg_ctl reload -U postgres -D "${pgdata}" -s
+	procd_add_restart_mount_trigger "${pgdata}"
 }
 
 stop_service() {
-	config_load "postgresql"
-	config_get pgdata config PGDATA
-	/usr/bin/pg_ctl stop -U postgres -D "${pgdata}" -s
+	procd_send_signal "postgresql" postmaster SIGTERM
 }
 
 status_service() {