Rebase

nomad/structs/node_class_test.go

@@ -13,6 +13,7 @@ func testNode() *Node {
 			"version":     "0.1.0",
 			"driver.exec": "1",
 		},
+		UniqueAttributes: make(map[string]struct{}),
 		Resources: &Resources{
 			CPU:      4000,
 			MemoryMB: 8192,

nomad/structs/structs.go

@@ -496,6 +496,9 @@ type Node struct {
 	// client. This is opaque to Nomad.
 	Meta map[string]string
 
+	// UniqueAttributes are attributes that uniquely identify a node.
+	UniqueAttributes map[string]struct{}
+
 	// NodeClass is an opaque identifier used to group nodes
 	// together for the purpose of determining scheduling pressure.
 	NodeClass string