Node.js
HTTP
post
Client

Node.js の http クライアントの使い方 (Post)

node-rest-client というライブラリーを使います。
インストール方法

sudo npm install node-rest-client
http_post.js
#! /usr/bin/node
// ---------------------------------------------------------------
//  http_post.js
//
//                  May/04/2018
//
// ---------------------------------------------------------------
var Client = require('node-rest-client').Client

var client = new Client()

var args = {
    data: { user: "jiro", password: "123456" },
    headers: { "Content-Type": "application/json" }
}

client.post("http://httpbin.org/post", args, function (data, response) {
    console.log(data)
})

// ---------------------------------------------------------------

実行結果

$ ./http_post.js 
{ args: {},
  data: '{"user":"jiro","password":"123456"}',
  files: {},
  form: {},
  headers: 
   { Connection: 'close',
     'Content-Length': '35',
     'Content-Type': 'application/json',
     Host: 'httpbin.org' },
  json: { password: '123456', user: 'jiro' },
  origin: '202.214.230.180',
  url: 'http://httpbin.org/post' }