cinder-csi-plugin: Don't report topology capability when --with-topology=False

The 'PluginCapability_Service_VOLUME_ACCESSIBILITY_CONSTRAINTS'
capability flag determines whether the provisioner attempts to look up
topology information from the node or not [1][2]. If we report it but
don't return topology information from the node, we end up with
failures to provision [3]. Fix the issue by optionally reporting the
capability, like Manila already does.

[1] https://github.com/kubernetes-csi/external-provisioner/blob/17e2429e9f/pkg/controller/controller.go#L685-L700
[2] https://github.com/kubernetes-csi/external-provisioner/blob/17e2429e9f/pkg/controller/controller.go#L994-L996
[3] https://github.com/kubernetes-csi/external-provisioner/blob/17e2429e9f/pkg/controller/topology.go#L177

Signed-off-by: Stephen Finucane <[email protected]>

Author: stephenfin

pkg/csi/cinder/identityserver.go

@@ -52,36 +52,39 @@ func (ids *identityServer) Probe(ctx context.Context, req *csi.ProbeRequest) (*c
 
 func (ids *identityServer) GetPluginCapabilities(ctx context.Context, req *csi.GetPluginCapabilitiesRequest) (*csi.GetPluginCapabilitiesResponse, error) {
 	klog.V(5).Infof("GetPluginCapabilities called with req %+v", req)
-	return &csi.GetPluginCapabilitiesResponse{
-		Capabilities: []*csi.PluginCapability{
-			{
-				Type: &csi.PluginCapability_Service_{
-					Service: &csi.PluginCapability_Service{
-						Type: csi.PluginCapability_Service_CONTROLLER_SERVICE,
-					},
+	caps := []*csi.PluginCapability{
+		{
+			Type: &csi.PluginCapability_Service_{
+				Service: &csi.PluginCapability_Service{
+					Type: csi.PluginCapability_Service_CONTROLLER_SERVICE,
 				},
 			},
-			{
-				Type: &csi.PluginCapability_Service_{
-					Service: &csi.PluginCapability_Service{
-						Type: csi.PluginCapability_Service_VOLUME_ACCESSIBILITY_CONSTRAINTS,
-					},
+		},
+		{
+			Type: &csi.PluginCapability_VolumeExpansion_{
+				VolumeExpansion: &csi.PluginCapability_VolumeExpansion{
+					Type: csi.PluginCapability_VolumeExpansion_ONLINE,
 				},
 			},
-			{
-				Type: &csi.PluginCapability_VolumeExpansion_{
-					VolumeExpansion: &csi.PluginCapability_VolumeExpansion{
-						Type: csi.PluginCapability_VolumeExpansion_ONLINE,
-					},
+		},
+		{
+			Type: &csi.PluginCapability_VolumeExpansion_{
+				VolumeExpansion: &csi.PluginCapability_VolumeExpansion{
+					Type: csi.PluginCapability_VolumeExpansion_OFFLINE,
 				},
 			},
-			{
-				Type: &csi.PluginCapability_VolumeExpansion_{
-					VolumeExpansion: &csi.PluginCapability_VolumeExpansion{
-						Type: csi.PluginCapability_VolumeExpansion_OFFLINE,
-					},
+		},
+	}
+
+	if ids.Driver.withTopology {
+		caps = append(caps, &csi.PluginCapability{
+			Type: &csi.PluginCapability_Service_{
+				Service: &csi.PluginCapability_Service{
+					Type: csi.PluginCapability_Service_VOLUME_ACCESSIBILITY_CONSTRAINTS,
 				},
 			},
-		},
-	}, nil
+		})
+	}
+
+	return &csi.GetPluginCapabilitiesResponse{Capabilities: caps}, nil
 }