Elasticsearch version (bin/elasticsearch --version):
Version: 5.5.1, Build: 19c13d0/2017-07-18T20:44:24.823Z

Plugins installed: []

JVM version (java -version):
openjdk version "1.8.0_131"

OS version (uname -a if on a Unix-like system):
Linux ubuntu 4.4.0-62-generic

Description of the problem including expected versus actual behavior:
I am running a single ES node bound to a specific IP address (network.host: 10.26.1.102). As per the docs, the _nodes request should return, among other things, http_address, and yet it doesn't. Other fields are present, but that one is not. Is this a bug, or are the docs outdated?

Steps to reproduce:
curl -XGET 10.26.1.102:9200/_nodes?pretty

Provide logs (if relevant):

"nodes" : {
  "MU4dFMhCRCOd-dmzkRoncA" : {
    "name" : "MU4dFMh",
    "transport_address" : "10.26.1.102:9300",
    "host" : "10.26.1.102",
    "ip" : "10.26.1.102",
    "version" : "5.5.1",
    "build_hash" : "19c13d0",
    "total_indexing_buffer" : 213876736,
    "roles" : [
      "master",
      "data",
      "ingest"
    ],
    ...