puppet: Use systemctl instead of pg_ctlcluster on CentOS.

puppet/zulip/manifests/postgres_appdb_tuned.pp

@@ -7,6 +7,10 @@ $postgres_conf = $::osfamily ? {
   'debian' => "/etc/postgresql/${zulip::base::postgres_version}/main/postgresql.conf",
   'redhat' => "/var/lib/pgsql/${zulip::base::postgres_version}/data/postgresql.conf",
 }
+$postgres_restart = $::osfamily ? {
+  'debian' => "pg_ctlcluster ${zulip::base::postgres_version} main restart",
+  'redhat' => "systemctl restart postgresql-${zulip::base::postgres_version}",
+}
 if $zulip::base::release_name == 'trusty' {
   # tools for database setup
   $postgres_appdb_tuned_packages = ['pgtune']
@@ -85,7 +89,7 @@ vm.dirty_background_ratio = 5
     content => template("zulip/postgresql/${zulip::base::postgres_version}/postgresql.conf.template.erb"),
   }
 
-  exec { "pg_ctlcluster ${zulip::base::postgres_version} main restart":
+  exec { $postgres_restart:
     require     => Package[$zulip::postgres_appdb_base::postgresql],
     refreshonly => true,
     subscribe   => [ File[$postgres_conf] ]

puppet/zulip_ops/files/postgresql/setup_disks.sh

@@ -15,6 +15,7 @@ mkfs.xfs /dev/md0
 echo "/dev/md0   /srv  xfs    nofail,noatime,barrier 1 1" >> /etc/fstab
 mount /srv
 
+# TODO use systemctl instead of pg_ctlcluster on CentOS
 pg_ctlcluster 9.5 main stop
 mv /var/lib/postgresql /srv
 ln -s /srv/postgresql/ /var/lib
@@ -23,6 +24,7 @@ mv /tmp /srv
 mkdir /tmp
 mount --bind /srv/tmp /tmp
 echo "/srv/tmp   /tmp  bind   nofail,defaults,bind 0 0" >> /etc/fstab
+# TODO use systemctl instead of pg_ctlcluster on CentOS
 pg_ctlcluster 9.5 main start
 
 # Disable /mnt line for /dev/xvdb