Cache not to be used to form node-template during scale from zero (#119…

…) (#127)

cluster-autoscaler/core/utils/utils.go

@@ -99,8 +99,9 @@ func GetNodeInfosForGroups(nodes []*apiv1.Node, nodeInfoCache map[string]*schedu
 			continue
 		}
 
-		// No good template, check cache of previously running nodes.
-		if nodeInfoCache != nil {
+		// No good template, check cache of previously running nodes(only when nodeGrp min size is not zero. This is to avoid scenarios where nodeGrp instanceType is updated,
+		// but still cached old nodeTemplate is used)
+		if nodeInfoCache != nil && nodeGroup.MinSize() != 0 {
 			if nodeInfo, found := nodeInfoCache[id]; found {
 				if nodeInfoCopy, err := deepCopyNodeInfo(nodeInfo); err == nil {
 					result[id] = nodeInfoCopy

cluster-autoscaler/core/utils/utils_test.go

@@ -210,7 +210,9 @@ func TestGetNodeInfosForGroupsCache(t *testing.T) {
 	assertEqualNodeCapacities(t, ready2, info.Node())
 	info, found = res["ng4"]
 	assert.True(t, found)
-	assertEqualNodeCapacities(t, ready6, info.Node())
+	/* The below line is commented , as now the nodeTemplate is not formed from previously ready node of nodegrp
+	if nodeGrp has min size 0 */
+	// assertEqualNodeCapacities(t, ready6, info.Node())
 }
 
 func assertEqualNodeCapacities(t *testing.T, expected, actual *apiv1.Node) {