enhance: Enable prefer node lables in resource group

add prefer node labels in resource groups, so resource group will prefer
to accept some node with given label.

Signed-off-by: Wei Liu <[email protected]>

proto/rg.proto

@@ -19,10 +19,15 @@ message ResourceGroupTransfer {
   string resource_group = 1; // resource groups can be transfered with current resource group.
   // preserve for other option, such as weight, priority or affinity setup.
 }
+
+message ResourceGroupNodeFilter {
+  repeated string prefer_node_labels = 1; // node in resource group must match node labels requirements
+}
 
 message ResourceGroupConfig {
   ResourceGroupLimit requests = 1; // requests node num in resource group, if node num is less than requests.nodeNum, it will be transfer from other resource group.
   ResourceGroupLimit limits = 2; // limited node num in resource group, if node num is more than limits.nodeNum, it will be transfer to other resource group.
   repeated ResourceGroupTransfer transfer_from = 3; // missing node should be transfer from given resource group at high priority in repeated list.
   repeated ResourceGroupTransfer transfer_to = 4; // redundant node should be transfer to given resource group at high priority in repeated list.
+  ResourceGroupNodeFilter node_filter = 5; // node in resource group must match node filters, otherwise node should be move out
 }