feat(datastore): Adding dynamic routing header (googleapis#8364)

datastore/client.go

@@ -17,6 +17,7 @@ package datastore
 import (
 	"context"
 	"fmt"
+	"net/url"
 	"time"
 
 	"cloud.google.com/go/datastore/internal"
@@ -43,14 +44,18 @@ type datastoreClient struct {
 }
 
 func newDatastoreClient(conn grpc.ClientConnInterface, projectID, databaseID string) pb.DatastoreClient {
-	resourcePrefixValue := "projects/" + projectID
-	if databaseID != "" {
-		resourcePrefixValue += "/databases/" + databaseID
+	resourcePrefixValue := "projects/" + url.QueryEscape(projectID)
+	reqParamsHeaderValue := "project_id=" + url.QueryEscape(projectID)
+
+	if databaseID != DefaultDatabaseID && databaseID != "" {
+		resourcePrefixValue += "/databases/" + url.QueryEscape(databaseID)
+		reqParamsHeaderValue += "&database_id=" + url.QueryEscape(databaseID)
 	}
 	return &datastoreClient{
 		c: pb.NewDatastoreClient(conn),
 		md: metadata.Pairs(
 			resourcePrefixHeader, resourcePrefixValue,
+			reqParamsHeader, reqParamsHeaderValue,
 			"x-goog-api-client", fmt.Sprintf("gl-go/%s gccl/%s grpc/", version.Go(), internal.Version)),
 	}
 }

datastore/datastore.go

@@ -53,6 +53,9 @@ const DetectProjectID = "*detect-project-id*"
 // the resource being operated on.
 const resourcePrefixHeader = "google-cloud-resource-prefix"
 
+// reqParamsHeader is routing header required to access named databases
+const reqParamsHeader = "x-goog-request-params"
+
 // DefaultDatabaseID is ID of the default database denoted by an empty string
 const DefaultDatabaseID = ""
 

datastore/integration_test.go

@@ -21,6 +21,7 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	"net/url"
 	"os"
 	"reflect"
 	"sort"
@@ -68,6 +69,10 @@ var (
 		return newClient(ctx, t, nil)
 	}
 	testParams map[string]interface{}
+
+	// xGoogReqParamsHeaderChecker is a HeaderChecker that ensures that the "x-goog-request-params"
+	// header is present on outgoing metadata.
+	xGoogReqParamsHeaderChecker *testutil.HeaderChecker
 )
 
 func TestMain(m *testing.M) {
@@ -121,6 +126,24 @@ func testMain(m *testing.M) int {
 	for _, databaseID := range databaseIDs {
 		log.Printf("Setting up tests to run on databaseID: %q\n", databaseID)
 		testParams["databaseID"] = databaseID
+		xGoogReqParamsHeaderChecker = &testutil.HeaderChecker{
+			Key: reqParamsHeader,
+			ValuesValidator: func(values ...string) error {
+				if len(values) == 0 {
+					return fmt.Errorf("missing values")
+				}
+				wantValue := fmt.Sprintf("project_id=%s", url.QueryEscape(testutil.ProjID()))
+				if databaseID != DefaultDatabaseID && databaseID != "" {
+					wantValue = fmt.Sprintf("%s&database_id=%s", wantValue, url.QueryEscape(databaseID))
+				}
+				for _, gotValue := range values {
+					if gotValue != wantValue {
+						return fmt.Errorf("got %s, want %s", gotValue, wantValue)
+					}
+				}
+				return nil
+			},
+		}
 		status := m.Run()
 		if status != 0 {
 			return status
@@ -153,6 +176,7 @@ func initReplay() {
 			OnFailure: t.Fatalf,
 			Checkers: []*testutil.HeaderChecker{
 				testutil.XGoogClientHeaderChecker,
+				xGoogReqParamsHeaderChecker,
 			},
 		}
 
@@ -179,6 +203,7 @@ func newClient(ctx context.Context, t *testing.T, dialOpts []grpc.DialOption) *C
 		OnFailure: t.Fatalf,
 		Checkers: []*testutil.HeaderChecker{
 			testutil.XGoogClientHeaderChecker,
+			xGoogReqParamsHeaderChecker,
 		},
 	}
 	opts := append(grpcHeadersEnforcer.CallOptions(), option.WithTokenSource(ts))