[curl] How do I make curl ignore the proxy?

I have http_proxy and https_proxy are defined. I don't want to unset and set again those environments but --noproxy '*' works perfectly for me.

curl --noproxy '*' -XGET 172.17.0.2:9200
{
  "status" : 200,
  "name" : "Medusa",
  "cluster_name" : "elasticsearch",
  "version" : {
    "number" : "1.5.0",
    "build_hash" : "544816042d40151d3ce4ba4f95399d7860dc2e92",
    "build_timestamp" : "2015-03-23T14:30:58Z",
    "build_snapshot" : false,
    "lucene_version" : "4.10.4"
  },
  "tagline" : "You Know, for Search"
}