openstack-manuals/doc/common/samples/server-scheduler-hints2.json

{
   "server":{
      "name":"server-1",
      "imageRef":"cedef40a-ed67-4d10-800e-17455edce175",
      "flavorRef":"1"
   },
   "os:scheduler_hints":{
      "query":"[>=,$free_ram_mb,1024]"
   }
}