Stop source-name loop on Google 403

A token without admin.directory.customer.readonly makes
Customers.Get return 403 forever. Treat that as terminal so
the source-name worker keeps the generic name and stops
retrying.

Signed-off-by: Bryan Frimin <bryan@probo.com>

pkg/accessreview/drivers/google_workspace_test.go

@@ -16,6 +16,8 @@ package drivers
 
 import (
 	"context"
+	"net/http"
+	"net/http/httptest"
 	"os"
 	"testing"
 
@@ -40,3 +42,64 @@ func TestGoogleWorkspaceDriver(t *testing.T) {
 	assert.NotEmpty(t, r.ExternalID)
 	assert.NotEmpty(t, r.Roles)
 }
+
+func TestGoogleWorkspaceNameResolver(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name    string
+		status  int
+		body    string
+		want    string
+		wantErr bool
+	}{
+		{
+			name:   "200 returns customer domain",
+			status: http.StatusOK,
+			body:   `{"kind":"admin#directory#customer","customerDomain":"example.com"}`,
+			want:   "example.com",
+		},
+		{
+			name:   "403 is terminal (no error, no name)",
+			status: http.StatusForbidden,
+			body:   `{"error":{"code":403,"message":"Not Authorized to access this resource/api","status":"FORBIDDEN"}}`,
+			want:   "",
+		},
+		{
+			name:    "500 is retryable",
+			status:  http.StatusInternalServerError,
+			body:    `{"error":{"code":500,"message":"Internal Server Error","status":"INTERNAL"}}`,
+			wantErr: true,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			srv := httptest.NewServer(
+				http.HandlerFunc(
+					func(w http.ResponseWriter, r *http.Request) {
+						assert.Equal(t, http.MethodGet, r.Method)
+						assert.Equal(t, "/admin/directory/v1/customers/my_customer", r.URL.Path)
+						w.Header().Set("Content-Type", "application/json")
+						w.WriteHeader(tc.status)
+						_, _ = w.Write([]byte(tc.body))
+					},
+				),
+			)
+			defer srv.Close()
+
+			client := &http.Client{Transport: &hostRewriter{target: srv.URL}}
+
+			got, err := NewGoogleWorkspaceNameResolver(client).ResolveInstanceName(t.Context())
+			if tc.wantErr {
+				require.Error(t, err)
+				return
+			}
+
+			require.NoError(t, err)
+			assert.Equal(t, tc.want, got)
+		})
+	}
+}

pkg/accessreview/drivers/name_resolver.go

@@ -18,12 +18,14 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
 
 	"go.probo.inc/probo/pkg/connector"
 	admin "google.golang.org/api/admin/directory/v1"
+	"google.golang.org/api/googleapi"
 	"google.golang.org/api/option"
 )
 
@@ -87,6 +89,11 @@ func (r *googleWorkspaceNameResolver) ResolveInstanceName(ctx context.Context) (
 
 	customer, err := adminService.Customers.Get("my_customer").Context(ctx).Do()
 	if err != nil {
+		var gerr *googleapi.Error
+		if errors.As(err, &gerr) && gerr.Code == http.StatusForbidden {
+			return "", nil
+		}
+
 		return "", fmt.Errorf("cannot fetch google workspace customer: %w", err)
 	}