Set MaxVolumesPerNode in NodeGetInfo

pkg/gce-cloud-provider/metadata/fake.go

@@ -26,6 +26,8 @@ const (
 	FakeProject    = "test-project"
 )
 
+var FakeMachineType = "n1-standard-1"
+
 func NewFakeService() MetadataService {
 	return &fakeServiceManager{}
 }
@@ -41,3 +43,11 @@ func (manager *fakeServiceManager) GetProject() string {
 func (manager *fakeServiceManager) GetName() string {
 	return "test-name"
 }
+
+func (manager *fakeServiceManager) GetMachineType() string {
+	return FakeMachineType
+}
+
+func SetMachineType(s string) {
+	FakeMachineType = s
+}

pkg/gce-cloud-provider/metadata/metadata.go

@@ -18,6 +18,7 @@ package metadata
 
 import (
 	"fmt"
+	"strings"
 
 	"cloud.google.com/go/compute/metadata"
 )
@@ -28,13 +29,15 @@ type MetadataService interface {
 	GetZone() string
 	GetProject() string
 	GetName() string
+	GetMachineType() string
 }
 
 type metadataServiceManager struct {
 	// Current zone the driver is running in
-	zone    string
-	project string
-	name    string
+	zone        string
+	project     string
+	name        string
+	machineType string
 }
 
 var _ MetadataService = &metadataServiceManager{}
@@ -52,11 +55,19 @@ func NewMetadataService() (MetadataService, error) {
 	if err != nil {
 		return nil, fmt.Errorf("failed to get instance name: %v", err)
 	}
+	fullMachineType, err := metadata.Get("instance/machine-type")
+	if err != nil {
+		return nil, fmt.Errorf("failed to get machine-type: %v", err)
+	}
+	// Response format: "projects/[NUMERIC_PROJECT_ID]/machineTypes/[MACHINE_TYPE]"
+	splits := strings.Split(fullMachineType, "/")
+	machineType := splits[len(splits)-1]
 
 	return &metadataServiceManager{
-		project: projectID,
-		zone:    zone,
-		name:    name,
+		project:     projectID,
+		zone:        zone,
+		name:        name,
+		machineType: machineType,
 	}, nil
 }
 
@@ -71,3 +82,7 @@ func (manager *metadataServiceManager) GetProject() string {
 func (manager *metadataServiceManager) GetName() string {
 	return manager.name
 }
+
+func (manager *metadataServiceManager) GetMachineType() string {
+	return manager.machineType
+}

pkg/gce-pd-csi-driver/node.go

@@ -17,6 +17,7 @@ package gceGCEDriver
 import (
 	"fmt"
 	"os"
+	"strings"
 	"sync"
 
 	csi "github.com/container-storage-interface/spec/lib/go/csi"
@@ -42,6 +43,14 @@ type GCENodeServer struct {
 
 var _ csi.NodeServer = &GCENodeServer{}
 
+// The constants are used to map from the machine type to the limit of
+// persistent disks that can be attached to an instance. Please refer to gcloud doc
+// https://cloud.google.com/compute/docs/disks/#pdnumberlimits
+const (
+	volumeLimit16  int64 = 16
+	volumeLimit128 int64 = 128
+)
+
 func (ns *GCENodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
 	ns.mux.Lock()
 	defer ns.mux.Unlock()
@@ -284,15 +293,17 @@ func (ns *GCENodeServer) NodeGetInfo(ctx context.Context, req *csi.NodeGetInfoRe
 
 	nodeID := common.CreateNodeID(ns.MetadataService.GetProject(), ns.MetadataService.GetZone(), ns.MetadataService.GetName())
 
+	volumeLimits, err := ns.GetVolumeLimits()
+
 	resp := &csi.NodeGetInfoResponse{
 		NodeId: nodeID,
 		// TODO(#19): Set MaxVolumesPerNode based on Node Type
 		// Default of 0 means that CO Decides how many nodes can be published
 		// Can get from metadata server "machine-type"
-		MaxVolumesPerNode:  0,
+		MaxVolumesPerNode:  volumeLimits,
 		AccessibleTopology: top,
 	}
-	return resp, nil
+	return resp, err
 }
 
 func (ns *GCENodeServer) NodeGetVolumeStats(ctx context.Context, req *csi.NodeGetVolumeStatsRequest) (*csi.NodeGetVolumeStatsResponse, error) {
@@ -302,3 +313,16 @@ func (ns *GCENodeServer) NodeGetVolumeStats(ctx context.Context, req *csi.NodeGe
 func (ns *GCENodeServer) NodeExpandVolume(ctx context.Context, req *csi.NodeExpandVolumeRequest) (*csi.NodeExpandVolumeResponse, error) {
 	return nil, status.Error(codes.Unimplemented, fmt.Sprintf("NodeExpandVolume is not yet implemented"))
 }
+
+func (ns *GCENodeServer) GetVolumeLimits() (int64, error) {
+	var volumeLimits int64
+
+	// Machine-type format: n1-type-CPUS or custom-CPUS-RAM or f1/g1-type
+	machineType := ns.MetadataService.GetMachineType()
+	if strings.HasPrefix(machineType, "n1-") || strings.HasPrefix(machineType, "custom-") {
+		volumeLimits = volumeLimit128
+	} else {
+		volumeLimits = volumeLimit16
+	}
+	return volumeLimits, nil
+}

pkg/gce-pd-csi-driver/node_test.go

@@ -13,3 +13,76 @@ limitations under the License.
 */
 
 package gceGCEDriver
+
+import (
+	"testing"
+
+	csi "github.com/container-storage-interface/spec/lib/go/csi"
+	"golang.org/x/net/context"
+	metadataservice "sigs.k8s.io/gcp-compute-persistent-disk-csi-driver/pkg/gce-cloud-provider/metadata"
+	mountmanager "sigs.k8s.io/gcp-compute-persistent-disk-csi-driver/pkg/mount-manager"
+)
+
+func getTestGCEDriver(t *testing.T) *GCEDriver {
+	gceDriver := GetGCEDriver()
+	err := gceDriver.SetupGCEDriver(nil, mountmanager.NewFakeSafeMounter(), mountmanager.NewFakeDeviceUtils(), metadataservice.NewFakeService(), driver, "test-vendor")
+	if err != nil {
+		t.Fatalf("Failed to setup GCE Driver: %v", err)
+	}
+	return gceDriver
+}
+
+func TestNodeGetVolumeLimits(t *testing.T) {
+
+	gceDriver := getTestGCEDriver(t)
+	ns := gceDriver.ns
+	req := &csi.NodeGetInfoRequest{}
+
+	testCases := []struct {
+		name           string
+		machineType    string
+		expVolumeLimit int64
+	}{
+		{
+			name:           "Predifined standard machine",
+			machineType:    "n1-standard-1",
+			expVolumeLimit: volumeLimit128,
+		},
+		{
+			name:           "Predifined micro machine",
+			machineType:    "f1-micro",
+			expVolumeLimit: volumeLimit16,
+		},
+		{
+			name:           "Predifined small machine",
+			machineType:    "g1-small",
+			expVolumeLimit: volumeLimit16,
+		},
+		{
+			name:           "Custom machine with 1GiB Mem",
+			machineType:    "custom-1-1024",
+			expVolumeLimit: volumeLimit128,
+		},
+		{
+			name:           "Custom machine with 4GiB Mem",
+			machineType:    "custom-2-4096",
+			expVolumeLimit: volumeLimit128,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Logf("Test case: %s", tc.name)
+		metadataservice.SetMachineType(tc.machineType)
+		res, err := ns.NodeGetInfo(context.Background(), req)
+		if err != nil {
+			t.Fatalf("Failed to get node info: %v", err)
+		} else {
+			volumeLimit := res.GetMaxVolumesPerNode()
+			if volumeLimit != tc.expVolumeLimit {
+				t.Fatalf("Expected volume limit: %v, got %v, for machine-type: %v",
+					tc.expVolumeLimit, volumeLimit, tc.machineType)
+			}
+			t.Logf("Get node info: %v", res)
+		}
+	}
+}

test/e2e/tests/single_zone_e2e_test.go

@@ -37,15 +37,24 @@ import (
 const (
 	testNamePrefix = "gcepd-csi-e2e-"
 
-	defaultSizeGb     int64 = 5
-	defaultRepdSizeGb int64 = 200
-	readyState              = "READY"
-	standardDiskType        = "pd-standard"
-	ssdDiskType             = "pd-ssd"
+	defaultSizeGb      int64 = 5
+	defaultRepdSizeGb  int64 = 200
+	readyState               = "READY"
+	standardDiskType         = "pd-standard"
+	ssdDiskType              = "pd-ssd"
+	defaultVolumeLimit int64 = 128
 )
 
 var _ = Describe("GCE PD CSI Driver", func() {
 
+	It("Should get reasonable volume limits from nodes with NodeGetInfo", func() {
+		testContext := getRandomTestContext()
+		resp, err := testContext.Client.NodeGetInfo()
+		Expect(err).To(BeNil())
+		volumeLimit := resp.GetMaxVolumesPerNode()
+		Expect(volumeLimit).To(Equal(defaultVolumeLimit))
+	})
+
 	It("Should create->attach->stage->mount volume and check if it is writable, then unmount->unstage->detach->delete and check disk is deleted", func() {
 		testContext := getRandomTestContext()