Annoying Client

Version 0.1.0
2018 Bojan Markovic
bmarkovic.79@gmail.com

Annoying Client is a HTTP client designed to emulate potentially infinitely long constant "pressure" to website. This is in contrast to tools like ab or wrk which are designed to simulate concurrent hammering of a web server over a limited number of requests or finite time.

Furthermore, while both ab and wrk are designed for web server becnhmarking annoying_client is primarily designed to "generate requests" i.e. simulate constant, normal traffic to a website in an unattended manner.

Although similar effect can be achieved using, say, wrk with LuaJIT scripting and cron, I was unable to find a solution for my specific use-case of generating constant traffic on a web server appearing to come from multiple clients and observing results in real time..

Installation

Requires Node.js 8 or newer. The installation is typical one for Node.js based software:

$ git clone https://github.com/bmarkovic/annoying-client.git
$ cd annoying-client
$ npm install

And then you start it with node . in the annoying-client directory.

Note: It was tested only on Linux and at the very least the tui mode (see below) is not very likely to work on Windows.

Configuration

The configuration should be in the config.json file in the same directory.

In this version it's possible to configure the following (the data given corresponds to the defaults apart from localAdresses and clientAuth which don't exist in the default config):

{
  // HTTP listening port
  httpPort: 9900,
  // Base URL for performed requests
  baseUrl: 'http://127.0.0.1/',
  // number of paralel fetches in each interval
  paralel: 10,
  // interval between batches of requests 250 -> 4 times per second
  // so with paralel set to 10 it equals 40 req/sec
  interval: 250,
  // percentage of requests to index URI
  index_pct: 60,
  // URI for index requests
  index: '/',
  // URIs for other requests
  otherUris: [
    '/foo',
    '/bar'
  ],
  // List of addresses (must be available on local ifaces)
  // that the traffic will seem to come from
  localAdresses: [
    "127.0.0.2",
    "127.0.0.3",
    "127.0.0.4",
    "127.0.0.5"
    ],
  // Auth header for client auth against the tested server.
  clientAuth: "Basic YW5ub3lpbmc6cGxhaW50ZXh0",
  // Can also be an object in the form:
  clientAuth: {
    username: "annoying"
    password: "plaintext"
  }
  // This configuration can be updated by performing a PUT request to the
  // /config URI. The request must be authenticated with Basic Auth.
  //
  // PUT auth username
  username: 'annoying',
  // PUT auth password SHA256 HEX obtainable with Node 'crypto' as:
  // hash = crypto.createHash('sha256').update(password).digest('hex')
  password: '9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08'
  // the one above is 'test'
}

The actual configuration must be in proper JSON format (quoted keys, no comments).

As noted above in the comments to the JSON config, configuration can be updated by PUT-ing of a JSON object with keys to override any of the options above to the /config URI endpoint.

If successful, the user will receive the config object stripped of password field as a confirmation of changes.

Stats

You can get the statistics on requests performed (and their results) by GET-ing the localhost:9900 (by default) URI in pretty-printed JSON. You can set up a watch to monitor in real time e.g.

$ watch 'curl -s localhost:9900'

Advanced usage

If you want test traffic to appear comming from multiple (loooback) addresses you can do so by creating a script that lifts loopback addresses before it starts the Annoying Client:

#!/bin/bash

ifconfig lo:1 127.0.0.2 up
ifconfig lo:2 127.0.0.3 up
ifconfig lo:3 127.0.0.4 up
ifconfig lo:4 127.0.0.5 up
# ... add as many as you need

cd annoying-client
node .

Another helpful option would be setting DEBUG to any "truthy" value. This will cause a special "tui" mode to be activated where the terminal is cleared every interval with updated stats. E.g.:

$ DEBUG=1 node .