Allow default workload identity pool name pattern (#15342)

Co-authored-by: Ben Hu <[email protected]>

Author: benhxy

mmv1/templates/terraform/constants/iam_workload_identity_pool.go.tmpl

@@ -1,4 +1,5 @@
 const workloadIdentityPoolIdRegexp = `^[0-9a-z-]+$`
+const defaultWorkloadIdentityPoolIdSuffix = ".svc.id.goog"
 
 func ValidateWorkloadIdentityPoolId(v interface{}, k string) (ws []string, errors []error) {
     value := v.(string)
@@ -8,9 +9,13 @@ func ValidateWorkloadIdentityPoolId(v interface{}, k string) (ws []string, error
             "%q (%q) can not start with \"gcp-\"", k, value))
     }
 
+    if strings.HasSuffix(value, defaultWorkloadIdentityPoolIdSuffix) {
+        value = strings.TrimRight(value, defaultWorkloadIdentityPoolIdSuffix)
+    }
+
     if !regexp.MustCompile(workloadIdentityPoolIdRegexp).MatchString(value) {
        errors = append(errors, fmt.Errorf(
-            "%q must contain only lowercase letters (a-z), numbers (0-9), or dashes (-)", k))
+            "%q must contain only lowercase letters (a-z), numbers (0-9), or dashes (-), or end in '.svc.id.goog'", k))
     }
 
     if len(value) < 4 {

mmv1/third_party/terraform/services/iambeta/resource_iam_workload_identity_pool_id_test.go

@@ -16,6 +16,7 @@ func TestValidateIAMBetaWorkloadIdentityPoolId(t *testing.T) {
 		{TestName: "short", Value: "foos"},
 		{TestName: "long", Value: "12345678901234567890123456789012"},
 		{TestName: "has a hyphen", Value: "foo-bar"},
+		{TestName: "default pool format", Value: "foo-bar.svc.id.goog"},
 
 		// With errors
 		{TestName: "empty", Value: "", ExpectError: true},