extend systemd define to handle instance systemd files

manifests/server/instance/config.pp

@@ -252,12 +252,11 @@
       notify => Class['postgresql::server::reload'],
     }
   }
-  # RHEL based systems and Gentoo need variables set for $PGPORT, $DATA_DIR or $PGDATA via a drop-in file
-  if $facts['os']['family'] == 'RedHat' or ($facts['os']['family'] == 'Gentoo' and $facts['service_provider'] == 'systemd') {
-    postgresql::server::instance::systemd { $service_name:
-      port                 => $port,
-      datadir              => $datadir,
-      extra_systemd_config => $extra_systemd_config,
-    }
+
+  postgresql::server::instance::systemd { $name:
+    port                 => $port,
+    datadir              => $datadir,
+    extra_systemd_config => $extra_systemd_config,
+    service_name         => $service_name,
   }
 }

manifests/server/instance/systemd.pp

@@ -5,26 +5,36 @@
 define postgresql::server::instance::systemd (
   Stdlib::Port $port,
   Stdlib::Absolutepath $datadir,
+  String[1] $instance_name                  = $name,
   Optional[String[1]] $extra_systemd_config = undef,
   String[1] $service_name                   = $name,
   Enum[present, absent] $drop_in_ensure     = 'present',
 ) {
-  # Template uses:
-  # - $port
-  # - $datadir
-  # - $extra_systemd_config
-  systemd::dropin_file { "${service_name}.conf":
-    ensure  => $drop_in_ensure,
-    unit    => "${service_name}.service",
-    owner   => 'root',
-    group   => 'root',
-    content => epp('postgresql/systemd-override.conf.epp', {
-        port                 => $port,
-        datadir              => $datadir,
-        extra_systemd_config => $extra_systemd_config,
+  if $facts['service_provider'] == 'systemd' {
+    if $facts['os']['family'] in ['RedHat', 'Gentoo'] {
+      # RHEL 7 and 8 both support drop-in files for systemd units.
+      # Gentoo also supports drop-in files.
+      # RHEL based Systems need Variables set for $PGPORT, $DATA_DIR or $PGDATA, thats what the drop-in file is for.
+      # For additional instances (!= 'main') we need a new systemd service anyhow and use one systemd-file. no dropin needed.
+      #
+      # Template uses:
+      # - $port
+      # - $datadir
+      # - $extra_systemd_config
+      systemd::dropin_file { "${service_name}.conf":
+        ensure  => $drop_in_ensure,
+        unit    => "${service_name}.service",
+        owner   => 'root',
+        group   => 'root',
+        content => epp('postgresql/systemd-override.conf.epp', {
+            port                 => $port,
+            datadir              => $datadir,
+            extra_systemd_config => $extra_systemd_config,
+          }
+        ),
+        notify  => Class['postgresql::server::service'],
+        before  => Class['postgresql::server::reload'],
       }
-    ),
-    notify  => Class['postgresql::server::service'],
-    before  => Class['postgresql::server::reload'],
+    }
   }
 }