Add option to only attempt table grant if table already exists

manifests/server/grant.pp

@@ -2,12 +2,13 @@
 define postgresql::server::grant (
   $role,
   $db,
-  $privilege   = undef,
-  $object_type = 'database',
-  $object_name = undef,
-  $psql_db     = $postgresql::server::default_database,
-  $psql_user   = $postgresql::server::user,
-  $port        = $postgresql::server::port
+  $privilege      = undef,
+  $object_type    = 'database',
+  $object_name    = undef,
+  $psql_db        = $postgresql::server::default_database,
+  $psql_user      = $postgresql::server::user,
+  $port           = $postgresql::server::port,
+  $onlyif_exists  = false,
 ) {
   $group     = $postgresql::server::group
   $psql_path = $postgresql::server::psql_path
@@ -22,6 +23,8 @@
   $_object_type = upcase($object_type)
   $_privilege   = upcase($privilege)
 
+  validate_bool($onlyif_exists)
+
   ## Validate that the object type is known
   validate_string($_object_type,
     #'COLUMN',
@@ -59,6 +62,7 @@
         'ALL','ALL PRIVILEGES')
       $unless_function = 'has_database_privilege'
       $on_db = $psql_db
+      $onlyif_function = undef
     }
     'SCHEMA': {
       $unless_privilege = $_privilege ? {
@@ -69,6 +73,7 @@
       validate_string($_privilege, 'CREATE', 'USAGE', 'ALL', 'ALL PRIVILEGES')
       $unless_function = 'has_schema_privilege'
       $on_db = $db
+      $onlyif_function = undef
     }
     'TABLE': {
       $unless_privilege = $_privilege ? {
@@ -79,12 +84,17 @@
         'TRUNCATE','REFERENCES','TRIGGER','ALL','ALL PRIVILEGES')
       $unless_function = 'has_table_privilege'
       $on_db = $db
+      $onlyif_function = $onlyif_exists ? {
+        true    => 'table_exists',
+        default => undef,
+      }
     }
     'ALL TABLES IN SCHEMA': {
       validate_string($_privilege,'SELECT','INSERT','UPDATE','DELETE',
         'TRUNCATE','REFERENCES','TRIGGER','ALL','ALL PRIVILEGES')
       $unless_function = 'custom'
       $on_db = $db
+      $onlyif_function = undef
 
       $schema = $object_name
 
@@ -150,6 +160,11 @@
                   '${_granted_object}', '${unless_privilege}')",
   }
 
+  $_onlyif = $onlyif_function ? {
+      'table_exists' => "SELECT true FROM pg_tables WHERE tablename = '${_togrant_object'",
+      default        => undef,
+  }
+
   $grant_cmd = "GRANT ${_privilege} ON ${_object_type} \"${_togrant_object}\" TO
       \"${role}\""
   postgresql_psql { "grant:${name}":
@@ -159,6 +174,7 @@
     psql_user  => $psql_user,
     psql_group => $group,
     psql_path  => $psql_path,
+    onlyif     => $_onlyif,
     unless     => $_unless,
     require    => Class['postgresql::server']
   }

manifests/server/table_grant.pp

@@ -5,18 +5,20 @@
   $table,
   $db,
   $role,
-  $port      = $postgresql::server::port,
-  $psql_db   = undef,
-  $psql_user = undef
+  $port                = $postgresql::server::port,
+  $psql_db             = undef,
+  $psql_user           = undef,
+  $onlyif_table_exists = false,
 ) {
   postgresql::server::grant { "table:${name}":
-    role        => $role,
-    db          => $db,
-    port        => $port,
-    privilege   => $privilege,
-    object_type => 'TABLE',
-    object_name => $table,
-    psql_db     => $psql_db,
-    psql_user   => $psql_user,
+    role                => $role,
+    db                  => $db,
+    port                => $port,
+    privilege           => $privilege,
+    object_type         => 'TABLE',
+    object_name         => $table,
+    psql_db             => $psql_db,
+    psql_user           => $psql_user,
+    onlyif_table_exists => $onlyif_table_exists,
   }
 }