postgresql_default_privileges: Allow empty privileges list (#118)

* allow empty list for postgresql_default_privileges

* add test for empty list in postgresql_default_privileges

* update docs for empty list in postgresql_default_privileges

* Duplicate new test step at the end to assert it revokes correctly.

Co-authored-by: Cyril Gaudin <cyril.gaudin@gmail.com>

postgresql/resource_postgresql_default_privileges.go

@@ -57,12 +57,11 @@ func resourcePostgreSQLDefaultPrivileges() *schema.Resource {
 				}, false),
 				Description: "The PostgreSQL object type to set the default privileges on (one of: table, sequence, function, type)",
 			},
-			"privileges": &schema.Schema{
+			"privileges": {
 				Type:        schema.TypeSet,
 				Required:    true,
 				Elem:        &schema.Schema{Type: schema.TypeString},
 				Set:         schema.HashString,
-				MinItems:    1,
 				Description: "The list of privileges to apply as default privileges",
 			},
 			"with_grant_option": {
@@ -183,6 +182,7 @@ func readRoleDefaultPrivileges(txn *sql.Tx, d *schema.ResourceData) error {
 	owner := d.Get("owner").(string)
 	pgSchema := d.Get("schema").(string)
 	objectType := d.Get("object_type").(string)
+	privilegesInput := d.Get("privileges").(*schema.Set).List()
 
 	if err := pgLockRole(txn, owner); err != nil {
 		return err
@@ -226,11 +226,13 @@ func readRoleDefaultPrivileges(txn *sql.Tx, d *schema.ResourceData) error {
 		return fmt.Errorf("could not read default privileges: %w", err)
 	}
 
-	// We consider no privileges as "not exists"
+	// We consider no privileges as "not exists" unless no privileges were provided as input
 	if len(privileges) == 0 {
 		log.Printf("[DEBUG] no default privileges for role %s in schema %s", role, pgSchema)
-		d.SetId("")
-		return nil
+		if len(privilegesInput) != 0 {
+			d.SetId("")
+			return nil
+		}
 	}
 
 	privilegesSet := pgArrayToSet(privileges)
@@ -249,6 +251,11 @@ func grantRoleDefaultPrivileges(txn *sql.Tx, d *schema.ResourceData) error {
 		privileges = append(privileges, priv.(string))
 	}
 
+	if len(privileges) == 0 {
+		log.Printf("[DEBUG] no default privileges to grant for role %s, owner %s in database: %s,", d.Get("role").(string), d.Get("owner").(string), d.Get("database").(string))
+		return nil
+	}
+
 	var inSchema string
 
 	// If a schema is specified we need to build the part of the query string to action this

postgresql/resource_postgresql_default_privileges_test.go

@@ -48,6 +48,23 @@ resource "postgresql_default_privileges" "test_ro" {
 				},
 				Providers: testAccProviders,
 				Steps: []resource.TestStep{
+					{
+						Config: fmt.Sprintf(tfConfig, `[]`),
+						Check: resource.ComposeTestCheckFunc(
+							func(*terraform.State) error {
+								tables := []string{"test_schema.test_table"}
+								// To test default privileges, we need to create a table
+								// after having apply the state.
+								dropFunc := createTestTables(t, dbSuffix, tables, "")
+								defer dropFunc()
+
+								return testCheckTablesPrivileges(t, dbName, roleName, tables, []string{})
+							},
+							resource.TestCheckResourceAttr("postgresql_default_privileges.test_ro", "object_type", "table"),
+							resource.TestCheckResourceAttr("postgresql_default_privileges.test_ro", "with_grant_option", fmt.Sprintf("%t", withGrant)),
+							resource.TestCheckResourceAttr("postgresql_default_privileges.test_ro", "privileges.#", "0"),
+						),
+					},
 					{
 						Config: fmt.Sprintf(tfConfig, `["SELECT"]`),
 						Check: resource.ComposeTestCheckFunc(
@@ -83,6 +100,23 @@ resource "postgresql_default_privileges" "test_ro" {
 							resource.TestCheckResourceAttr("postgresql_default_privileges.test_ro", "privileges.1759376126", "UPDATE"),
 						),
 					},
+					{
+						Config: fmt.Sprintf(tfConfig, `[]`),
+						Check: resource.ComposeTestCheckFunc(
+							func(*terraform.State) error {
+								tables := []string{"test_schema.test_table"}
+								// To test default privileges, we need to create a table
+								// after having apply the state.
+								dropFunc := createTestTables(t, dbSuffix, tables, "")
+								defer dropFunc()
+
+								return testCheckTablesPrivileges(t, dbName, roleName, tables, []string{})
+							},
+							resource.TestCheckResourceAttr("postgresql_default_privileges.test_ro", "object_type", "table"),
+							resource.TestCheckResourceAttr("postgresql_default_privileges.test_ro", "with_grant_option", fmt.Sprintf("%t", withGrant)),
+							resource.TestCheckResourceAttr("postgresql_default_privileges.test_ro", "privileges.#", "0"),
+						),
+					},
 				},
 			})
 		})

website/docs/r/postgresql_default_privileges.html.markdown

@@ -31,6 +31,21 @@ resource "postgresql_default_privileges" "read_only_tables" {
 * `role` - (Required) The name of the role to which grant default privileges on.
 * `database` - (Required) The database to grant default privileges for this role.
 * `owner` - (Required) Role for which apply default privileges (You can change default privileges only for objects that will be created by yourself or by roles that you are a member of).
-* `schema` - (Required) The database schema to set default privileges for this role.
+* `schema` - (Optional) The database schema to set default privileges for this role.
 * `object_type` - (Required) The PostgreSQL object type to set the default privileges on (one of: table, sequence, function, type).
-* `privileges` - (Required) The list of privileges to apply as default privileges.
+* `privileges` - (Required) The list of privileges to apply as default privileges. An empty list could be provided to revoke all default privileges for this role.
+
+
+## Examples
+
+Revoke default privileges for functions for "public" role:
+
+```hcl
+resource "postgresql_default_priviliges" "revoke_public" {
+  database    = postgresql_database.example_db.name
+  role        = "public"
+  owner       = "object_owner"
+  object_type = "function"
+  privileges  = []
+}
+```